Genes that influence the PHENOTYPE only in the homozygous state.
The magnitude of INBREEDING in humans.
The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
An individual in which both alleles at a given locus are identical.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
A genetic disorder with autosomal recessive inheritance, characterized by multiple CYSTS in both KIDNEYS and associated LIVER lesions. Serious manifestations are usually present at BIRTH with high PERINATAL MORTALITY.
The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.
Any method used for determining the location of and relative distances between genes on a chromosome.
Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.
Biochemical identification of mutational changes in a nucleotide sequence.
A characteristic symptom complex.
An individual having different alleles at one or more loci regarding a specific character.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.
A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)
The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.
Any of several generalized skin disorders characterized by dryness, roughness, and scaliness, due to hypertrophy of the stratum corneum epidermis. Most are genetic, but some are acquired, developing in association with other systemic disease or genetic syndrome.
'Abnormalities, Multiple' is a broad term referring to the presence of two or more structural or functional anomalies in an individual, which may be genetic or environmental in origin, and can affect various systems and organs of the body.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
An amino acid-specifying codon that has been converted to a stop codon (CODON, TERMINATOR) by mutation. Its occurance is abnormal causing premature termination of protein translation and results in production of truncated and non-functional proteins. A nonsense mutation is one that converts an amino acid-specific codon to a stop codon.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A congenital abnormality in which the CEREBRUM is underdeveloped, the fontanels close prematurely, and, as a result, the head is small. (Desk Reference for Neuroscience, 2nd ed.)
Form of epidermolysis bullosa characterized by atrophy of blistered areas, severe scarring, and nail changes. It is most often present at birth or in early infancy and occurs in both autosomal dominant and recessive forms. All forms of dystrophic epidermolysis bullosa result from mutations in COLLAGEN TYPE VII, a major component fibrils of BASEMENT MEMBRANE and EPIDERMIS.
The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.
The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.
A general term for the complete loss of the ability to hear from both ears.
Presence of less than the normal amount of hair. (Dorland, 27th ed)
A type of mutation in which a number of NUCLEOTIDES deleted from or inserted into a protein coding sequence is not divisible by three, thereby causing an alteration in the READING FRAMES of the entire coding sequence downstream of the mutation. These mutations may be induced by certain types of MUTAGENS or may occur spontaneously.
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Subnormal intellectual functioning which originates during the developmental period. This has multiple potential etiologies, including genetic defects and perinatal insults. Intelligence quotient (IQ) scores are commonly used to determine whether an individual has an intellectual disability. IQ scores between 70 and 79 are in the borderline range. Scores below 67 are in the disabled range. (from Joynt, Clinical Neurology, 1992, Ch55, p28)
Identification of genetic carriers for a given trait.
The presence of apparently similar characters for which the genetic evidence indicates that different genes or different genetic mechanisms are involved in different pedigrees. In clinical settings genetic heterogeneity refers to the presence of a variety of genetic defects which cause the same disease, often due to mutations at different loci on the same gene, a finding common to many human diseases including ALZHEIMER DISEASE; CYSTIC FIBROSIS; LIPOPROTEIN LIPASE DEFICIENCY, FAMILIAL; and POLYCYSTIC KIDNEY DISEASES. (Rieger, et al., Glossary of Genetics: Classical and Molecular, 5th ed; Segen, Dictionary of Modern Medicine, 1992)
Designation for several severe forms of ichthyosis, present at birth, that are characterized by hyperkeratotic scaling. Infants may be born encased in a collodion membrane which begins shedding within 24 hours. This is followed in about two weeks by persistent generalized scaling. The forms include bullous (HYPERKERATOSIS, EPIDERMOLYTIC), non-bullous (ICHTHYOSIS, LAMELLAR), wet type, and dry type.
That part of the genome that corresponds to the complete complement of EXONS of an organism or cell.
A phenomenon that is observed when a small subgroup of a larger POPULATION establishes itself as a separate and isolated entity. The subgroup's GENE POOL carries only a fraction of the genetic diversity of the parental population resulting in an increased frequency of certain diseases in the subgroup, especially those diseases known to be autosomal recessive.
The health status of the family as a unit including the impact of the health of one member of the family on the family as a unit and on individual family members; also, the impact of family organization or disorganization on the health status of its members.
I'm sorry for any confusion, but "Pakistan" is a country located in South Asia and it does not have a medical definition. If you have any medical question or term that you would like me to define, please provide it and I will be happy to help.
A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.
A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
Hearing loss resulting from damage to the COCHLEA and the sensorineural elements which lie internally beyond the oval and round windows. These elements include the AUDITORY NERVE and its connections in the BRAINSTEM.
The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.
A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).
Abnormal development of cartilage and bone.
Incoordination of voluntary movements that occur as a manifestation of CEREBELLAR DISEASES. Characteristic features include a tendency for limb movements to overshoot or undershoot a target (dysmetria), a tremor that occurs during attempted movements (intention TREMOR), impaired force and rhythm of diadochokinesis (rapidly alternating movements), and GAIT ATAXIA. (From Adams et al., Principles of Neurology, 6th ed, p90)
A chronic, congenital ichthyosis inherited as an autosomal recessive trait. Infants are usually born encased in a collodion membrane which sheds within a few weeks. Scaling is generalized and marked with grayish-brown quadrilateral scales, adherent at their centers and free at the edges. In some cases, scales are so thick that they resemble armored plate.
A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
A genetic or pathological condition that is characterized by short stature and undersize. Abnormal skeletal growth usually results in an adult who is significantly below the average height.
Diseases that are caused by genetic mutations present during embryo or fetal development, although they may be observed later in life. The mutations may be inherited from a parent's genome or they may be acquired in utero.
A non-fibrillar collagen involved in anchoring the epidermal BASEMENT MEMBRANE to underlying tissue. It is a homotrimer comprised of C-terminal and N-terminal globular domains connected by a central triple-helical region.
A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.
A heterogeneous group of inherited MYOPATHIES, characterized by wasting and weakness of the SKELETAL MUSCLE. They are categorized by the sites of MUSCLE WEAKNESS; AGE OF ONSET; and INHERITANCE PATTERNS.
Detection of a MUTATION; GENOTYPE; KARYOTYPE; or specific ALLELES associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing.
The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.
A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.
Developmental bone diseases are a category of skeletal disorders that arise from disturbances in the normal growth and development of bones, including abnormalities in size, shape, structure, or composition, which can lead to various musculoskeletal impairments and deformities.
Group of genetically determined disorders characterized by the blistering of skin and mucosae. There are four major forms: acquired, simple, junctional, and dystrophic. Each of the latter three has several varieties.
Variation in a population's DNA sequence that is detected by determining alterations in the conformation of denatured DNA fragments. Denatured DNA fragments are allowed to renature under conditions that prevent the formation of double-stranded DNA and allow secondary structure to form in single stranded fragments. These fragments are then run through polyacrylamide gels to detect variations in the secondary structure that is manifested as an alteration in migration through the gels.
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder.
The different ways GENES and their ALLELES interact during the transmission of genetic traits that effect the outcome of GENE EXPRESSION.
Excessive formation of dense trabecular bone leading to pathological fractures; OSTEITIS; SPLENOMEGALY with infarct; ANEMIA; and extramedullary hemopoiesis (HEMATOPOIESIS, EXTRAMEDULLARY).
Errors in metabolic processes resulting from inborn genetic mutations that are inherited or acquired in utero.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Mice bearing mutant genes which are phenotypically expressed in the animals.
Members of a Semitic people inhabiting the Arabian peninsula or other countries of the Middle East and North Africa. The term may be used with reference to ancient, medieval, or modern ethnic or cultural groups. (From Random House Unabridged Dictionary, 2d ed)
'Eye proteins' are structural or functional proteins, such as crystallins, opsins, and collagens, located in various parts of the eye, including the cornea, lens, retina, and aqueous humor, that contribute to maintaining transparency, refractive power, phototransduction, and overall integrity of the visual system.
Mutation process that restores the wild-type PHENOTYPE in an organism possessing a mutationally altered GENOTYPE. The second "suppressor" mutation may be on a different gene, on the same gene but located at a distance from the site of the primary mutation, or in extrachromosomal genes (EXTRACHROMOSOMAL INHERITANCE).
A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.
Inherited myotonic disorders with early childhood onset MYOTONIA. Muscular hypertrophy is common and myotonia may impair ambulation and other movements. It is classified as Thomsen (autosomal dominant) or Becker (autosomal recessive) generalized myotonia mainly based on the inheritance pattern. Becker type is also clinically more severe. An autosomal dominant variant with milder symptoms and later onset is known as myotonia levior. Mutations in the voltage-dependent skeletal muscle chloride channel are associated with the disorders.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
The age, developmental stage, or period of life at which a disease or the initial symptoms or manifestations of a disease appear in an individual.
A hereditary motor and sensory neuropathy transmitted most often as an autosomal dominant trait and characterized by progressive distal wasting and loss of reflexes in the muscles of the legs (and occasionally involving the arms). Onset is usually in the second to fourth decade of life. This condition has been divided into two subtypes, hereditary motor and sensory neuropathy (HMSN) types I and II. HMSN I is associated with abnormal nerve conduction velocities and nerve hypertrophy, features not seen in HMSN II. (Adams et al., Principles of Neurology, 6th ed, p1343)
Deletion of sequences of nucleic acids from the genetic material of an individual.
A general term for the complete or partial loss of the ability to hear from one or both ears.
A group of hereditary disorders involving tissues and structures derived from the embryonic ectoderm. They are characterized by the presence of abnormalities at birth and involvement of both the epidermis and skin appendages. They are generally nonprogressive and diffuse. Various forms exist, including anhidrotic and hidrotic dysplasias, FOCAL DERMAL HYPOPLASIA, and aplasia cutis congenita.
An autosomal recessive disease, usually of childhood onset, characterized pathologically by degeneration of the spinocerebellar tracts, posterior columns, and to a lesser extent the corticospinal tracts. Clinical manifestations include GAIT ATAXIA, pes cavus, speech impairment, lateral curvature of spine, rhythmic head tremor, kyphoscoliosis, congestive heart failure (secondary to a cardiomyopathy), and lower extremity weakness. Most forms of this condition are associated with a mutation in a gene on chromosome 9, at band q13, which codes for the mitochondrial protein frataxin. (From Adams et al., Principles of Neurology, 6th ed, p1081; N Engl J Med 1996 Oct 17;335(16):1169-75) The severity of Friedreich ataxia associated with expansion of GAA repeats in the first intron of the frataxin gene correlates with the number of trinucleotide repeats. (From Durr et al, N Engl J Med 1996 Oct 17;335(16):1169-75)
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Recording of electric potentials in the retina after stimulation by light.
Defective bone formation involving individual bones, singly or in combination.
An antineoplastic agent with alkylating properties. It also acts as a mutagen by damaging DNA and is used experimentally for that effect.
An infant during the first month after birth.
Clinical conditions caused by an abnormal chromosome constitution in which there is extra or missing chromosome material (either a whole chromosome or a chromosome segment). (from Thompson et al., Genetics in Medicine, 5th ed, p429)
Deformities in nail structure or appearance, including hypertrophy, splitting, clubbing, furrowing, etc. Genetic diseases such as PACHYONYCHIA CONGENITA can result in malformed nails.
A social group consisting of parents or parent substitutes and children.
A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)
Coloration or discoloration of a part by a pigment.
Heterogeneous group of autosomal recessive disorders comprising at least four recognized types, all having in common varying degrees of hypopigmentation of the skin, hair, and eyes. The two most common are the tyrosinase-positive and tyrosinase-negative types.
An ethnic group with historical ties to the land of ISRAEL and the religion of JUDAISM.
Congenital or developmental anomaly in which the eyeballs are abnormally small.
Persistent flexure or contracture of a joint.
A congenital anomaly of the hand or foot, marked by the webbing between adjacent fingers or toes. Syndactylies are classified as complete or incomplete by the degree of joining. Syndactylies can also be simple or complex. Simple syndactyly indicates joining of only skin or soft tissue; complex syndactyly marks joining of bony elements.
A group of connective tissue diseases in which skin hangs in loose pendulous folds. It is believed to be associated with decreased elastic tissue formation as well as an abnormality in elastin formation. Cutis laxa is usually a genetic disease, but acquired cases have been reported. (From Dorland, 27th ed)
A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.
A heterogeneous group of hereditary and acquired disorders in which the KIDNEY contains one or more CYSTS unilaterally or bilaterally (KIDNEY, CYSTIC).
The analysis of a sequence such as a region of a chromosome, a haplotype, a gene, or an allele for its involvement in controlling the phenotype of a specific trait, metabolic pathway, or disease.
A group of disorders marked by progressive degeneration of motor neurons in the spinal cord resulting in weakness and muscular atrophy, usually without evidence of injury to the corticospinal tracts. Diseases in this category include Werdnig-Hoffmann disease and later onset SPINAL MUSCULAR ATROPHIES OF CHILDHOOD, most of which are hereditary. (Adams et al., Principles of Neurology, 6th ed, p1089)
Congenital absence of or defects in structures of the eye; may also be hereditary.
A group of genetic disorders of the KIDNEY TUBULES characterized by the accumulation of metabolically produced acids with elevated plasma chloride, hyperchloremic metabolic ACIDOSIS. Defective renal acidification of URINE (proximal tubules) or low renal acid excretion (distal tubules) can lead to complications such as HYPOKALEMIA, hypercalcinuria with NEPHROLITHIASIS and NEPHROCALCINOSIS, and RICKETS.
Alterations or deviations from normal shape or size which result in a disfigurement of the foot occurring at or before birth.
Diseases affecting the orderly growth and persistence of hair.
A group of inherited disorders characterized by degeneration of dorsal root and autonomic ganglion cells, and clinically by loss of sensation and autonomic dysfunction. There are five subtypes. Type I features autosomal dominant inheritance and distal sensory involvement. Type II is characterized by autosomal inheritance and distal and proximal sensory loss. Type III is DYSAUTONOMIA, FAMILIAL. Type IV features insensitivity to pain, heat intolerance, and mental deficiency. Type V is characterized by a selective loss of pain with intact light touch and vibratory sensation. (From Joynt, Clinical Neurology, 1995, Ch51, pp142-4)
Disorders affecting amino acid metabolism. The majority of these disorders are inherited and present in the neonatal period with metabolic disturbances (e.g., ACIDOSIS) and neurologic manifestations. They are present at birth, although they may not become symptomatic until later in life.
A group of inherited diseases that share similar phenotypes but are genetically diverse. Different genetic loci for autosomal recessive, autosomal dominant, and x-linked forms of hereditary spastic paraplegia have been identified. Clinically, patients present with slowly progressive distal limb weakness and lower extremity spasticity. Peripheral sensory neurons may be affected in the later stages of the disease. (J Neurol Neurosurg Psychiatry 1998 Jan;64(1):61-6; Curr Opin Neurol 1997 Aug;10(4):313-8)
Genetic diseases that are linked to gene mutations on the X CHROMOSOME in humans (X CHROMOSOME, HUMAN) or the X CHROMOSOME in other species. Included here are animal models of human X-linked diseases.
A family of transmembrane dystrophin-associated proteins that play a role in the membrane association of the DYSTROPHIN-ASSOCIATED PROTEIN COMPLEX.
Hereditary diseases that are characterized by the progressive expansion of a large number of tightly packed CYSTS within the KIDNEYS. They include diseases with autosomal dominant and autosomal recessive inheritance.
A SMN complex protein that is essential for the function of the SMN protein complex. In humans the protein is encoded by a single gene found near the inversion telomere of a large inverted region of CHROMOSOME 5. Mutations in the gene coding for survival of motor neuron 1 protein may result in SPINAL MUSCULAR ATROPHIES OF CHILDHOOD.
The functional hereditary units of PLANTS.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
A metabolic disease characterized by the defective transport of CYSTINE across the lysosomal membrane due to mutation of a membrane protein cystinosin. This results in cystine accumulation and crystallization in the cells causing widespread tissue damage. In the KIDNEY, nephropathic cystinosis is a common cause of RENAL FANCONI SYNDROME.
The percent frequency with which a dominant or homozygous recessive gene or gene combination manifests itself in the phenotype of the carriers. (From Glossary of Genetics, 5th ed)
Atrophy of the optic disk which may be congenital or acquired. This condition indicates a deficiency in the number of nerve fibers which arise in the RETINA and converge to form the OPTIC DISK; OPTIC NERVE; OPTIC CHIASM; and optic tracts. GLAUCOMA; ISCHEMIA; inflammation, a chronic elevation of intracranial pressure, toxins, optic nerve compression, and inherited conditions (see OPTIC ATROPHIES, HEREDITARY) are relatively common causes of this condition.
The appearance of the face that is often characteristic of a disease or pathological condition, as the elfin facies of WILLIAMS SYNDROME or the mongoloid facies of DOWN SYNDROME. (Random House Unabridged Dictionary, 2d ed)
A country in northern Africa between ALGERIA and LIBYA. Its capital is Tunis.
A diminution of the skeletal muscle tone marked by a diminished resistance to passive stretching.
Congenital disorder affecting all bone marrow elements, resulting in ANEMIA; LEUKOPENIA; and THROMBOPENIA, and associated with cardiac, renal, and limb malformations as well as dermal pigmentary changes. Spontaneous CHROMOSOME BREAKAGE is a feature of this disease along with predisposition to LEUKEMIA. There are at least 7 complementation groups in Fanconi anemia: FANCA, FANCB, FANCC, FANCD1, FANCD2, FANCE, FANCF, FANCG, and FANCL. (from Online Mendelian Inheritance in Man, http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=227650, August 20, 2004)
A species of fruit fly much used in genetics because of the large size of its chromosomes.
Group of mostly hereditary disorders characterized by thickening of the palms and soles as a result of excessive keratin formation leading to hypertrophy of the stratum corneum (hyperkeratosis).
Color of hair or fur.
Abnormal number or structure of the SEX CHROMOSOMES. Some sex chromosome aberrations are associated with SEX CHROMOSOME DISORDERS and SEX CHROMOSOME DISORDERS OF SEX DEVELOPMENT.
A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.
Congenital structural deformities, malformations, or other abnormalities of the cranium and facial bones.
Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.
Failure or imperfection of vision at night or in dim light, with good vision only on bright days. (Dorland, 27th ed)
The relative amount by which the average fitness of a POPULATION is lowered, due to the presence of GENES that decrease survival, compared to the GENOTYPE with maximum or optimal fitness. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.
Acquired, familial, and congenital disorders of SKELETAL MUSCLE and SMOOTH MUSCLE.
The mating of plants or non-human animals which are closely related genetically.
Congenital structural deformities of the upper and lower extremities collectively or unspecified.
Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.
I'm sorry for any confusion, but the term "Lebanon" is a geographical name and not a medical condition or term. It is the name of a country located in the Middle East, known for its rich history, diverse culture, and beautiful landscapes. If you have any questions related to medical definitions or health-related topics, I would be happy to help!
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or PERIPHERAL NERVE DISEASES. Motor ataxia may be associated with CEREBELLAR DISEASES; CEREBRAL CORTEX diseases; THALAMIC DISEASES; BASAL GANGLIA DISEASES; injury to the RED NUCLEUS; and other conditions.
Alterations or deviations from normal shape or size which result in a disfigurement of the hand occurring at or before birth.
A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
A group of disorders which feature impaired motor control characterized by bradykinesia, MUSCLE RIGIDITY; TREMOR; and postural instability. Parkinsonian diseases are generally divided into primary parkinsonism (see PARKINSON DISEASE), secondary parkinsonism (see PARKINSON DISEASE, SECONDARY) and inherited forms. These conditions are associated with dysfunction of dopaminergic or closely related motor integration neuronal pathways in the BASAL GANGLIA.
A group of recessively inherited diseases that feature progressive muscular atrophy and hypotonia. They are classified as type I (Werdnig-Hoffman disease), type II (intermediate form), and type III (Kugelberg-Welander disease). Type I is fatal in infancy, type II has a late infantile onset and is associated with survival into the second or third decade. Type III has its onset in childhood, and is slowly progressive. (J Med Genet 1996 Apr:33(4):281-3)
Nucleotide sequences located at the ends of EXONS and recognized in pre-messenger RNA by SPLICEOSOMES. They are joined during the RNA SPLICING reaction, forming the junctions between exons.
An autosomal recessive disorder characterized by RETINITIS PIGMENTOSA; POLYDACTYLY; OBESITY; MENTAL RETARDATION; hypogenitalism; renal dysplasia; and short stature. This syndrome has been distinguished as a separate entity from LAURENCE-MOON SYNDROME. (From J Med Genet 1997 Feb;34(2):92-8)
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
COLLAGEN DISEASES characterized by brittle, osteoporotic, and easily fractured bones. It may also present with blue sclerae, loose joints, and imperfect dentin formation. Most types are autosomal dominant and are associated with mutations in COLLAGEN TYPE I.
A specific pair GROUP C CHROMSOMES of the human chromosome classification.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
A diverse class of enzymes that interact with UBIQUITIN-CONJUGATING ENZYMES and ubiquitination-specific protein substrates. Each member of this enzyme group has its own distinct specificity for a substrate and ubiquitin-conjugating enzyme. Ubiquitin-protein ligases exist as both monomeric proteins multiprotein complexes.
A complex of proteins that assemble the SNRNP CORE PROTEINS into a core structure that surrounds a highly conserved RNA sequence found in SMALL NUCLEAR RNA. They are found localized in the GEMINI OF COILED BODIES and in the CYTOPLASM. The SMN complex is named after the Survival of Motor Neuron Complex Protein 1, which is a critical component of the complex.
Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed)
Congenital absence of or defects in structures of the teeth.
An autosomal recessive inherited disorder characterized by choreoathetosis beginning in childhood, progressive CEREBELLAR ATAXIA; TELANGIECTASIS of CONJUNCTIVA and SKIN; DYSARTHRIA; B- and T-cell immunodeficiency, and RADIOSENSITIVITY to IONIZING RADIATION. Affected individuals are prone to recurrent sinobronchopulmonary infections, lymphoreticular neoplasms, and other malignancies. Serum ALPHA-FETOPROTEINS are usually elevated. (Menkes, Textbook of Child Neurology, 5th ed, p688) The gene for this disorder (ATM) encodes a cell cycle checkpoint protein kinase and has been mapped to chromosome 11 (11q22-q23).
Mapping of the linear order of genes on a chromosome with units indicating their distances by using methods other than genetic recombination. These methods include nucleotide sequencing, overlapping deletions in polytene chromosomes, and electron micrography of heteroduplex DNA. (From King & Stansfield, A Dictionary of Genetics, 5th ed)
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Genes that have a suppressor allele or suppressor mutation (SUPPRESSION, GENETIC) which cancels the effect of a previous mutation, enabling the wild-type phenotype to be maintained or partially restored. For example, amber suppressors cancel the effect of an AMBER NONSENSE MUTATION.
Autosomal recessive hereditary disorders characterized by congenital SENSORINEURAL HEARING LOSS and RETINITIS PIGMENTOSA. Genetically and symptomatically heterogeneous, clinical classes include type I, type II, and type III. Their severity, age of onset of retinitis pigmentosa and the degree of vestibular dysfunction are variable.
A defect of leukocyte function in which phagocytic cells ingest but fail to digest bacteria, resulting in recurring bacterial infections with granuloma formation. When chronic granulomatous disease is caused by mutations in the CYBB gene, the condition is inherited in an X-linked recessive pattern. When chronic granulomatous disease is caused by CYBA, NCF1, NCF2, or NCF4 gene mutations, the condition is inherited in an autosomal recessive pattern.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
Genotypic differences observed among individuals in a population.
A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.
A family composed of spouses and their children.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Gross hypo- or aplasia of one or more long bones of one or more limbs. The concept includes amelia, hemimelia, phocomelia, and sirenomelia.
Persons or animals having at least one parent in common. (American College Dictionary, 3d ed)
The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
I'm sorry for any confusion, but "Syria" is a country located in Western Asia and is not a medical term or concept. It is the birthplace of the ancient Assyrian civilization and is known for its rich history, diverse culture, and complex geopolitical context. If you have any questions related to medicine or healthcare, I would be happy to try to help answer them for you.
A clinically and genetically heterogeneous group of hereditary conditions characterized by malformed DENTAL ENAMEL, usually involving DENTAL ENAMEL HYPOPLASIA and/or TOOTH HYPOMINERALIZATION.
Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.
The human female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in humans.
One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).
A heterogenous group of inherited muscular dystrophy that can be autosomal dominant or autosomal recessive. There are many forms (called LGMDs) involving genes encoding muscle membrane proteins such as the sarcoglycan (SARCOGLYCANS) complex that interacts with DYSTROPHIN. The disease is characterized by progressing wasting and weakness of the proximal muscles of arms and legs around the HIPS and SHOULDERS (the pelvic and shoulder girdles).
A group of dominantly inherited, predominately late-onset, cerebellar ataxias which have been divided into multiple subtypes based on clinical features and genetic mapping. Progressive ataxia is a central feature of these conditions, and in certain subtypes POLYNEUROPATHY; DYSARTHRIA; visual loss; and other disorders may develop. (From Joynt, Clinical Neurology, 1997, Ch65, pp 12-17; J Neuropathol Exp Neurol 1998 Jun;57(6):531-43)
Determination of the nature of a pathological condition or disease in the postimplantation EMBRYO; FETUS; or pregnant female before birth.
Birth defect that results in a partial or complete absence of the CORPUS CALLOSUM. It may be isolated or a part of a syndrome (e.g., AICARDI'S SYNDROME; ACROCALLOSAL SYNDROME; ANDERMANN SYNDROME; and HOLOPROSENCEPHALY). Clinical manifestations include neuromotor skill impairment and INTELLECTUAL DISABILITY of variable severity.
A group of disorders involving predominantly the posterior portion of the ocular fundus, due to degeneration in the sensory layer of the RETINA; RETINAL PIGMENT EPITHELIUM; BRUCH MEMBRANE; CHOROID; or a combination of these tissues.
An inherited disorder of connective tissue with extensive degeneration and calcification of ELASTIC TISSUE primarily in the skin, eye, and vasculature. At least two forms exist, autosomal recessive and autosomal dominant. This disorder is caused by mutations of one of the ATP-BINDING CASSETTE TRANSPORTERS. Patients are predisposed to MYOCARDIAL INFARCTION and GASTROINTESTINAL HEMORRHAGE.
A congenital anomaly of the hand or foot, marked by the presence of supernumerary digits.
The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)
A group of homologous proteins which form the intermembrane channels of GAP JUNCTIONS. The connexins are the products of an identified gene family which has both highly conserved and highly divergent regions. The variety contributes to the wide range of functional properties of gap junctions.
Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.
A group of HEREDITARY AUTOINFLAMMATION DISEASES, characterized by recurrent fever, abdominal pain, headache, rash, PLEURISY; and ARTHRITIS. ORCHITIS; benign MENINGITIS; and AMYLOIDOSIS may also occur. Homozygous or compound heterozygous mutations in marenostrin gene result in autosomal recessive transmission; simple heterozygous, autosomal dominant form of the disease.
A cyclic nucleotide phosphodiesterase subfamily that is highly specific for CYCLIC GMP. It is found predominantly in the outer segment PHOTORECEPTOR CELLS of the RETINA. It is comprised of two catalytic subunits, referred to as alpha and beta, that form a dimer. In addition two regulatory subunits, referred to as gamma and delta, modulate the activity and localization of the enzyme.
The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.
Any codon that signals the termination of genetic translation (TRANSLATION, GENETIC). PEPTIDE TERMINATION FACTORS bind to the stop codon and trigger the hydrolysis of the aminoacyl bond connecting the completed polypeptide to the tRNA. Terminator codons do not specify amino acids.
A rare degenerative inherited eye disease that appears at birth or in the first few months of life that results in a loss of vision. Not to be confused with LEBER HEREDITARY OPTIC NEUROPATHY, the disease is thought to be caused by abnormal development of PHOTORECEPTOR CELLS in the RETINA, or by the extremely premature degeneration of retinal cells.
I'm sorry for any confusion, but "Israel" is a country in the Middle East and does not have a medical definition. If you have any medical questions or terms you would like me to define, I'd be happy to help!
The functional hereditary units of FUNGI.
An autosomal recessive disorder characterized by glassy degenerative thickening (hyalinosis) of SKIN; MUCOSA; and certain VISCERA. This disorder is caused by mutation in the extracellular matrix protein 1 gene (ECM1). Clinical features include hoarseness and skin eruption due to widespread deposition of HYALIN.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
The presence of methemoglobin in the blood, resulting in cyanosis. A small amount of methemoglobin is present in the blood normally, but injury or toxic agents convert a larger proportion of hemoglobin into methemoglobin, which does not function reversibly as an oxygen carrier. Methemoglobinemia may be due to a defect in the enzyme NADH methemoglobin reductase (an autosomal recessive trait) or to an abnormality in hemoglobin M (an autosomal dominant trait). (Dorland, 27th ed)

Assaying potential carcinogens with Drosophila. (1/2914)

Drosophila offers many advantages for the detection of mutagenic activity of carcinogenic agents. It provides the quickest assay system for detecting mutations in animals today. Its generation time is short, and Drosophila is cheap and easy to breed in large numbers. The simple genetic testing methods give unequivocal answers about the whole spectrum of relevant genetic damage. A comparison of the detection capacity of assays sampling different kinds of genetic damage revealed that various substances are highly effective in inducing mutations but do not produce chromosome breakage effects at all, or only at much higher concentrations than those required for mutation induction. Of the different assay systems available, the classical sex-linked recessive lethal test deserves priority, in view of its superior capacity to detect mutagens. Of practical importance is also its high sensitivity, because a large number of loci in one fifth of the genome is tested for newly induced forward mutations, including small deletions. The recent findings that Drosophila is capable of carrying out the same metabolic activation reactions as the mammalian liver makes the organism eminently suitable for verifying results obtained in prescreening with fast microbial assay systems. An additional advantage in this respect is the capacity of Drosophila for detecting short-lived activation products, because intracellular metabolic activation appears to occur within the spermatids and spermatocytes.  (+info)

Nonbehavioral selection for pawns, mutants of Paramecium aurelia with decreased excitability. (2/2914)

The reversal response in Paramecium aurelia is mediated by calcium which carries the inward current during excitation. Electrophysiological studies indicate that strontium and barium can also carry the inward current. Exposure to high concentrations of barium rapidly paralyzes and later kills wild-type paramecia. Following mutagenesis with nitrosoguanidine, seven mutants which continued to swim in the ;high-barium' solution were selected. All of the mutants show decreased reversal behavior, with phenotypes ranging from extremely non-reversing (;extreme' pawns) to nearly wild-type reversal behavior (;partial' pawns). The mutations fall into three complementation groups, identical to the pwA, pwB, and pwC genes of Kunget al. (1975). All of the pwA and pwB mutants withstand longer exposure to barium, the pwB mutants surviving longer than the pwA mutants. Among mutants of each gene, survival is correlated with loss of reversal behavior. Double mutants (A-B, A-C, B-C), identified in the exautogamous progeny of crosses between ;partial' mutants, exhibited a more extreme non-reversing phenotype than either of their single-mutant (;partial' pawn) parents.---Inability to reverse could be expected from an alteration in the calcium-activated reversal mechanism or in excitation. A normal calcium-activated structure was demonstrated in all pawns by chlorpromazine treatment. In a separate report (Schein, Bennett and Katz 1976) the results of electrophysiological investigations directly demonstrate decreased excitability in all of the mutants, a decrease due to an altered calcium activation. The studies of the genetics, the survival in barium and the electro-physiology of the pawns demonstrate that the pwA and pwB genes have different effects on calcium activation.  (+info)

The muscle chloride channel ClC-1 has a double-barreled appearance that is differentially affected in dominant and recessive myotonia. (3/2914)

Single-channel recordings of the currents mediated by the muscle Cl- channel, ClC-1, expressed in Xenopus oocytes, provide the first direct evidence that this channel has two equidistant open conductance levels like the Torpedo ClC-0 prototype. As for the case of ClC-0, the probabilities and dwell times of the closed and conducting states are consistent with the presence of two independently gated pathways with approximately 1.2 pS conductance enabled in parallel via a common gate. However, the voltage dependence of the common gate is different and the kinetics are much faster than for ClC-0. Estimates of single-channel parameters from the analysis of macroscopic current fluctuations agree with those from single-channel recordings. Fluctuation analysis was used to characterize changes in the apparent double-gate behavior of the ClC-1 mutations I290M and I556N causing, respectively, a dominant and a recessive form of myotonia. We find that both mutations reduce about equally the open probability of single protopores and that mutation I290M yields a stronger reduction of the common gate open probability than mutation I556N. Our results suggest that the mammalian ClC-homologues have the same structure and mechanism proposed for the Torpedo channel ClC-0. Differential effects on the two gates that appear to modulate the activation of ClC-1 channels may be important determinants for the different patterns of inheritance of dominant and recessive ClC-1 mutations.  (+info)

A wide variety of mutations in the parkin gene are responsible for autosomal recessive parkinsonism in Europe. French Parkinson's Disease Genetics Study Group and the European Consortium on Genetic Susceptibility in Parkinson's Disease. (4/2914)

Autosomal recessive juvenile parkinsonism (AR-JP, PARK2; OMIM 602544), one of the monogenic forms of Parkinson's disease (PD), was initially described in Japan. It is characterized by early onset (before age 40), marked response to levodopa treatment and levodopa-induced dyskinesias. The gene responsible for AR-JP was recently identified and designated parkin. We have analysed the 12 coding exons of the parkin gene in 35 mostly European families with early onset autosomal recessive parkinsonism. In one family, a homozygous deletion of exon 4 could be demonstrated. By direct sequencing of the exons in the index patients of the remaining 34 families, eight previously undescribed point mutations (homozygous or heterozygous) were detected in eight families that included 20 patients. The mutations segregated with the disease in the families and were not detected on 110-166 control chromosomes. Four mutations caused truncation of the parkin protein. Three were frameshifts (202-203delAG, 255delA and 321-322insGT) and one a nonsense mutation (Trp453Stop). The other four were missense mutations (Lys161Asn, Arg256Cys, Arg275Trp and Thr415Asn) that probably affect amino acids that are important for the function of the parkin protein, since they result in the same phenotype as truncating mutations or homozygous exon deletions. Mean age at onset was 38 +/- 12 years, but onset up to age 58 was observed. Mutations in the parkin gene are therefore not invariably associated with early onset parkinsonism. In many patients, the phenotype is indistinguishable from that of idiopathic PD. This study has shown that a wide variety of different mutations in the parkin gene are a common cause of autosomal recessive parkinsonism in Europe and that different types of point mutations seem to be more frequently responsible for the disease phenotype than are deletions.  (+info)

Characterization of a new form of inherited hypercholesterolemia: familial recessive hypercholesterolemia. (5/2914)

We previously described a Sardinian family in which the probands had a severe form of hypercholesterolemia, suggestive of familial hypercholesterolemia (FH). However, low density lipoprotein (LDL) receptor activity in fibroblasts from these subjects and LDL binding ability were normal. The characteristics of the pedigree were consistent with an autosomal recessive trait. Sitosterolemia and pseudohomozygous hyperlipidemia were ruled out. A second Sardinian kindred with similar characteristics was identified. Probands showed severe hypercholesterolemia, whereas their parents and grandparents were normolipidemic. FH, familial defective apoprotein (apo) B, sitosterolemia, and cholesteryl ester storage disease were excluded by in vitro studies. We addressed the metabolic basis of this inherited disorder by studying the in vivo metabolism of LDL in 3 probands from these 2 families. 125I-LDL turnover studies disclosed a marked reduction in the fractional catabolic rate (0.19+/-0.01 versus 0.36+/-0.03 pools per day, respectively; P<0.001) and a significant increase in the production rate [20.7+/-4.4 versus 14. 0+/-2.4 mg. kg-1. d-1, respectively; P<0.01] of LDL apoB in the probands compared with normolipidemic controls. We then studied the in vivo biodistribution and tissue uptake of 99mtechnetium-labeled LDL in the probands and compared them with those in normal controls and 1 FH homozygote. The probands showed a significant reduction in hepatic LDL uptake, similar to that observed in the FH homozygote. A reduced uptake of LDL by the kidney and spleen was also observed in all patients. Our findings suggest that this recessive form of hypercholesterolemia is due to a marked reduction of in vivo LDL catabolism. This appears to be caused by a selective reduction in hepatic LDL uptake. We propose that in this new lipid disorder, a recessive defect causes a selective impairment of LDL receptor function in the liver.  (+info)

Homozygous deletion in KVLQT1 associated with Jervell and Lange-Nielsen syndrome. (6/2914)

BACKGROUND: Long-QT (LQT) syndrome is a cardiac disorder that causes syncope, seizures, and sudden death from ventricular arrhythmias, specifically torsade de pointes. Both autosomal dominant LQT (Romano-Ward syndrome) and autosomal recessive LQT (Jervell and Lange-Nielsen syndrome, JLNS) have been reported. Heterozygous mutations in 3 potassium channel genes, KVLQT1, KCNE1 (minK), and HERG, and the cardiac sodium channel gene SCN5A cause autosomal dominant LQT. Autosomal recessive LQT, which is associated with deafness, has been found to occur with homozygous mutations in KVLQT1 and KCNE1 in JLNS families in which QTc prolongation was inherited as a dominant trait. METHODS AND RESULTS: An Amish family with clinical evidence of JLNS was analyzed for mutations by use of single-strand conformation polymorphism and DNA sequencing analyses for mutations in all known LQT genes. A novel homozygous 2-bp deletion in the S2 transmembrane segment of KVLQT1 was identified in affected members of this Amish family in which both QTc prolongation and deafness were inherited as recessive traits. This deletion represents a new JLNS-associated mutation in KVLQT1 and has deleterious effects on the KVLQT1 potassium channel, causing a frameshift and the truncation of the KVLQT1 protein. In contrast to previous reports in which LQT was inherited as a clear dominant trait, 2 parents in the JLNS family described here have normal QTc intervals (0.43 and 0.44 seconds, respectively). CONCLUSIONS: A novel homozygous KVLQT1 mutation causes JLNS in an Amish family with deafness that is inherited as an autosomal recessive trait.  (+info)

High-resolution physical and genetic mapping of the critical region for Meckel syndrome and Mulibrey Nanism on chromosome 17q22-q23. (7/2914)

Previously, we assigned the genes for two autosomal recessive disorders, Meckel syndrome (MKS; MIM 249000) and Mulibrey Nanism [MUL (muscle-liver-brain-eye Nanism); MIM 253250] that are enriched in the Finnish population, to overlapping genomic regions on chromosome 17q. Now, we report the construction of a bacterial clone contig over the critical region for both disorders. Several novel CA-repeat markers were isolated from these clones, which allowed refined mapping of the MKS and MUL loci using haplotype and linkage disequilibrium analysis. The localization of the MKS locus was narrowed to <1 cM between markers D17S1290 and 132-CA, within an approximately 800-kb region. The MUL locus was refined into an approximately 1400-kb interval between markers D17S1290 and 52-CA. The whole MKS region falls within the MUL region. In the common critical region, the conserved haplotypes were different in MKS and MUL patients. A trancript map was constructed by assigning expressed sequence tags (ESTs) and genes, derived from the human gene map, to the bacterial clone contig. Altogether, four genes and a total of 20 ESTs were precisely localized. These data provide the molecular tools for the final identification of the MKS and the MUL genes.  (+info)

An arrested late endosome-lysosome intermediate aggregate observed in a Chinese hamster ovary cell mutant isolated by novel three-step screening. (8/2914)

Chinese hamster ovary cell mutants defective in the post-uptake degradation of low-density lipoprotein (LDL) in lysosomes were selected from mutagenized cells by novel three-step screening. First, in the presence of LDL, clones sensitive to an inhibitor of the rate-limiting enzyme of the cholesterol biosynthetic pathway, 3-hydroxy-3-methylglutaryl-CoA reductase, were isolated. Second, from the selected clones, those lacking in the degradation of a constituent of a fluorescent LDL were qualitatively screened by microscopy. Third, the clones were further screened by previously established quantitative analytical flow cytometry that detects the early-phase disintegration of LDL by lysosomal acid hydrolases. One of the isolated mutant clones, LEX1 (Lysosome-Endosome X 1), was a recessive mutant, and exhibited a specific disorder in the late endocytic pathway. LEX1 cells showed an unusual perinuclear aggregate of vesicles, heterogeneously positive for lysosomal glycoprotein-B/cathepsin D and rab7, yet negative for the cation-independent mannose 6-phosphate receptor. The aggregate was formed around the microtubule organizing center, and was disrupted by nocodazole treatment. Internalized octadecyl rhodamine B-labeled LDL (R18-LDL) was accumulated in the perinuclear rab7-positive vesicles. In a Percoll density gradient, neither internalized R18-LDL nor internalized horseradish peroxidase was efficiently chased into heavy lysosomal fractions positive for beta-hexosaminidase. LEX1 cells showed differences in the activity and subcellular distribution of lysosomal enzymes. These characteristics of LEX1 cells are consistent with the ideas that the perinuclear vesicle aggregate is an arrested intermediate of direct fusion or divergence between lysosomes and rab7-positive, cation-independent mannose 6-phosphate receptor-negative late endosomes, and that equilibrium between the lysosomes and the late endosomes is shifted towards the late endosomes in LEX1 cells. Such fusion or divergence between the late endosomes and the lysosomes would determine an appropriate equilibrium between them, and might thereby play an important role for proper lysosomal digestive functions. LEX1 mutant cells would be helpful for the dissection of the as yet unrevealed details of the late endocytic membrane dynamics and for the identification of factors involved in the process arrested by the mutation.  (+info)

Recessive genes refer to the alleles (versions of a gene) that will only be expressed when an individual has two copies of that particular allele, one inherited from each parent. If an individual inherits one recessive allele and one dominant allele for a particular gene, the dominant allele will be expressed and the recessive allele will have no effect on the individual's phenotype (observable traits).

Recessive genes can still play a role in determining an individual's genetic makeup and can be passed down through generations even if they are not expressed. If two carriers of a recessive gene have children, there is a 25% chance that their offspring will inherit two copies of the recessive allele and exhibit the associated recessive trait.

Examples of genetic disorders caused by recessive genes include cystic fibrosis, sickle cell anemia, and albinism.

Consanguinity is a medical and genetic term that refers to the degree of genetic relationship between two individuals who share common ancestors. Consanguineous relationships exist when people are related by blood, through a common ancestor or siblings who have children together. The closer the relationship between the two individuals, the higher the degree of consanguinity.

The degree of consanguinity is typically expressed as a percentage or fraction, with higher values indicating a closer genetic relationship. For example, first-degree relatives, such as parents and children or full siblings, share approximately 50% of their genes and have a consanguinity coefficient of 0.25 (or 25%).

Consanguinity can increase the risk of certain genetic disorders and birth defects in offspring due to the increased likelihood of sharing harmful recessive genes. The risks depend on the degree of consanguinity, with closer relationships carrying higher risks. It is important for individuals who are planning to have children and have a history of consanguinity to consider genetic counseling and testing to assess their risk of passing on genetic disorders.

I must clarify that the term "pedigree" is not typically used in medical definitions. Instead, it is often employed in genetics and breeding, where it refers to the recorded ancestry of an individual or a family, tracing the inheritance of specific traits or diseases. In human genetics, a pedigree can help illustrate the pattern of genetic inheritance in families over multiple generations. However, it is not a medical term with a specific clinical definition.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

A homozygote is an individual who has inherited the same allele (version of a gene) from both parents and therefore possesses two identical copies of that allele at a specific genetic locus. This can result in either having two dominant alleles (homozygous dominant) or two recessive alleles (homozygous recessive). In contrast, a heterozygote has inherited different alleles from each parent for a particular gene.

The term "homozygote" is used in genetics to describe the genetic makeup of an individual at a specific locus on their chromosomes. Homozygosity can play a significant role in determining an individual's phenotype (observable traits), as having two identical alleles can strengthen the expression of certain characteristics compared to having just one dominant and one recessive allele.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

Autosomal recessive polycystic kidney disease (ARPKD) is a rare genetic disorder characterized by the abnormal development and growth of numerous fluid-filled cysts in both kidneys. "Autosomal recessive" indicates that an individual must inherit two copies of the mutated gene, one from each parent, to develop the condition.

The disease primarily affects the renal tubules, which are the tiny structures inside the kidneys responsible for concentrating urine and reabsorbing essential substances back into the bloodstream. In ARPKD, these tubules become dilated and form cysts, leading to progressive kidney enlargement, scarring, and decreased function.

ARPKD is typically diagnosed in infancy or early childhood, and its severity can vary widely among affected individuals. Some may experience mild kidney impairment, while others may develop end-stage renal disease (ESRD) requiring dialysis or a kidney transplant. Additionally, ARPKD often affects the liver, causing congenital hepatic fibrosis and potentially leading to complications such as portal hypertension and liver failure.

The condition is caused by mutations in the PKHD1 gene, which provides instructions for producing a large protein called fibrocystin or polyductin. This protein plays crucial roles in maintaining the structure and function of renal tubules and bile ducts in the liver. When the PKHD1 gene is mutated, it results in the production of an abnormal or nonfunctional fibrocystin/polyductin protein, ultimately leading to the development of cysts and other associated symptoms.

Genetic linkage is the phenomenon where two or more genetic loci (locations on a chromosome) tend to be inherited together because they are close to each other on the same chromosome. This occurs during the process of sexual reproduction, where homologous chromosomes pair up and exchange genetic material through a process called crossing over.

The closer two loci are to each other on a chromosome, the lower the probability that they will be separated by a crossover event. As a result, they are more likely to be inherited together and are said to be linked. The degree of linkage between two loci can be measured by their recombination frequency, which is the percentage of meiotic events in which a crossover occurs between them.

Linkage analysis is an important tool in genetic research, as it allows researchers to identify and map genes that are associated with specific traits or diseases. By analyzing patterns of linkage between markers (identifiable DNA sequences) and phenotypes (observable traits), researchers can infer the location of genes that contribute to those traits or diseases on chromosomes.

Chromosome mapping, also known as physical mapping, is the process of determining the location and order of specific genes or genetic markers on a chromosome. This is typically done by using various laboratory techniques to identify landmarks along the chromosome, such as restriction enzyme cutting sites or patterns of DNA sequence repeats. The resulting map provides important information about the organization and structure of the genome, and can be used for a variety of purposes, including identifying the location of genes associated with genetic diseases, studying evolutionary relationships between organisms, and developing genetic markers for use in breeding or forensic applications.

Dominant genes refer to the alleles (versions of a gene) that are fully expressed in an individual's phenotype, even if only one copy of the gene is present. In dominant inheritance patterns, an individual needs only to receive one dominant allele from either parent to express the associated trait. This is in contrast to recessive genes, where both copies of the gene must be the recessive allele for the trait to be expressed. Dominant genes are represented by uppercase letters (e.g., 'A') and recessive genes by lowercase letters (e.g., 'a'). If an individual inherits one dominant allele (A) from either parent, they will express the dominant trait (A).

DNA Mutational Analysis is a laboratory test used to identify genetic variations or changes (mutations) in the DNA sequence of a gene. This type of analysis can be used to diagnose genetic disorders, predict the risk of developing certain diseases, determine the most effective treatment for cancer, or assess the likelihood of passing on an inherited condition to offspring.

The test involves extracting DNA from a patient's sample (such as blood, saliva, or tissue), amplifying specific regions of interest using polymerase chain reaction (PCR), and then sequencing those regions to determine the precise order of nucleotide bases in the DNA molecule. The resulting sequence is then compared to reference sequences to identify any variations or mutations that may be present.

DNA Mutational Analysis can detect a wide range of genetic changes, including single-nucleotide polymorphisms (SNPs), insertions, deletions, duplications, and rearrangements. The test is often used in conjunction with other diagnostic tests and clinical evaluations to provide a comprehensive assessment of a patient's genetic profile.

It is important to note that not all mutations are pathogenic or associated with disease, and the interpretation of DNA Mutational Analysis results requires careful consideration of the patient's medical history, family history, and other relevant factors.

A syndrome, in medical terms, is a set of symptoms that collectively indicate or characterize a disease, disorder, or underlying pathological process. It's essentially a collection of signs and/or symptoms that frequently occur together and can suggest a particular cause or condition, even though the exact physiological mechanisms might not be fully understood.

For example, Down syndrome is characterized by specific physical features, cognitive delays, and other developmental issues resulting from an extra copy of chromosome 21. Similarly, metabolic syndromes like diabetes mellitus type 2 involve a group of risk factors such as obesity, high blood pressure, high blood sugar, and abnormal cholesterol or triglyceride levels that collectively increase the risk of heart disease, stroke, and diabetes.

It's important to note that a syndrome is not a specific diagnosis; rather, it's a pattern of symptoms that can help guide further diagnostic evaluation and management.

A heterozygote is an individual who has inherited two different alleles (versions) of a particular gene, one from each parent. This means that the individual's genotype for that gene contains both a dominant and a recessive allele. The dominant allele will be expressed phenotypically (outwardly visible), while the recessive allele may or may not have any effect on the individual's observable traits, depending on the specific gene and its function. Heterozygotes are often represented as 'Aa', where 'A' is the dominant allele and 'a' is the recessive allele.

An allele is a variant form of a gene that is located at a specific position on a specific chromosome. Alleles are alternative forms of the same gene that arise by mutation and are found at the same locus or position on homologous chromosomes.

Each person typically inherits two copies of each gene, one from each parent. If the two alleles are identical, a person is said to be homozygous for that trait. If the alleles are different, the person is heterozygous.

For example, the ABO blood group system has three alleles, A, B, and O, which determine a person's blood type. If a person inherits two A alleles, they will have type A blood; if they inherit one A and one B allele, they will have type AB blood; if they inherit two B alleles, they will have type B blood; and if they inherit two O alleles, they will have type O blood.

Alleles can also influence traits such as eye color, hair color, height, and other physical characteristics. Some alleles are dominant, meaning that only one copy of the allele is needed to express the trait, while others are recessive, meaning that two copies of the allele are needed to express the trait.

Retinitis pigmentosa (RP) is a group of rare, genetic disorders that involve a breakdown and loss of cells in the retina - a light-sensitive tissue located at the back of the eye. The retina converts light into electrical signals which are then sent to the brain and interpreted as visual images.

In RP, the cells that detect light (rods and cones) degenerate more slowly than other cells in the retina, leading to a progressive loss of vision. Symptoms typically begin in childhood with night blindness (difficulty seeing in low light), followed by a gradual narrowing of the visual field (tunnel vision). Over time, this can lead to significant vision loss and even blindness.

The condition is usually inherited and there are several different genes that have been associated with RP. The diagnosis is typically made based on a combination of genetic testing, family history, and clinical examination. Currently, there is no cure for RP, but researchers are actively working to develop new treatments that may help slow or stop the progression of the disease.

A missense mutation is a type of point mutation in which a single nucleotide change results in the substitution of a different amino acid in the protein that is encoded by the affected gene. This occurs when the altered codon (a sequence of three nucleotides that corresponds to a specific amino acid) specifies a different amino acid than the original one. The function and/or stability of the resulting protein may be affected, depending on the type and location of the missense mutation. Missense mutations can have various effects, ranging from benign to severe, depending on the importance of the changed amino acid for the protein's structure or function.

A LOD (Logarithm of Odds) score is not a medical term per se, but rather a statistical concept that is used in genetic research and linkage analysis to determine the likelihood of a gene or genetic marker being linked to a particular disease or trait. The LOD score compares the odds of observing the pattern of inheritance of a genetic marker in a family if the marker is linked to the disease, versus the odds if the marker is not linked. A LOD score of 3 or higher is generally considered evidence for linkage, while a score of -2 or lower is considered evidence against linkage.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

A lethal gene is a type of gene that causes the death of an organism or prevents it from surviving to maturity. This can occur when the gene contains a mutation that disrupts the function of a protein essential for the organism's survival. In some cases, the presence of two copies of a lethal gene (one inherited from each parent) can result in a condition that is incompatible with life, and the organism will not survive beyond embryonic development or shortly after birth.

Lethal genes can also contribute to genetic disorders, where the disruption of protein function caused by the mutation leads to progressive degeneration and ultimately death. In some cases, lethal genes may only cause harm when expressed in certain tissues or at specific stages of development, leading to a range of phenotypes from embryonic lethality to adult-onset disorders.

It's important to note that the term "lethal" is relative and can depend on various factors such as genetic background, environmental conditions, and the presence of modifier genes. Additionally, some lethal genes may be targeted for gene editing or other therapeutic interventions to prevent their harmful effects.

Ichthyosis is a group of skin disorders that are characterized by dry, thickened, scaly skin. The name "ichthyosis" comes from the Greek word "ichthys," which means fish, as the skin can have a fish-like scale appearance. These conditions can be inherited or acquired and vary in severity.

The medical definition of ichthyosis is a heterogeneous group of genetic keratinization disorders that result in dry, thickened, and scaly skin. The condition may affect any part of the body, but it most commonly appears on the extremities, scalp, and trunk. Ichthyosis can also have associated symptoms such as redness, itching, and blistering.

The severity of ichthyosis can range from mild to severe, and some forms of the condition may be life-threatening in infancy. The exact symptoms and their severity depend on the specific type of ichthyosis a person has. Treatment for ichthyosis typically involves moisturizing the skin, avoiding irritants, and using medications to help control scaling and inflammation.

'Abnormalities, Multiple' is a broad term that refers to the presence of two or more structural or functional anomalies in an individual. These abnormalities can be present at birth (congenital) or can develop later in life (acquired). They can affect various organs and systems of the body and can vary greatly in severity and impact on a person's health and well-being.

Multiple abnormalities can occur due to genetic factors, environmental influences, or a combination of both. Chromosomal abnormalities, gene mutations, exposure to teratogens (substances that cause birth defects), and maternal infections during pregnancy are some of the common causes of multiple congenital abnormalities.

Examples of multiple congenital abnormalities include Down syndrome, Turner syndrome, and VATER/VACTERL association. Acquired multiple abnormalities can result from conditions such as trauma, infection, degenerative diseases, or cancer.

The medical evaluation and management of individuals with multiple abnormalities depend on the specific abnormalities present and their impact on the individual's health and functioning. A multidisciplinary team of healthcare professionals is often involved in the care of these individuals to address their complex needs.

Genotype, in genetics, refers to the complete heritable genetic makeup of an individual organism, including all of its genes. It is the set of instructions contained in an organism's DNA for the development and function of that organism. The genotype is the basis for an individual's inherited traits, and it can be contrasted with an individual's phenotype, which refers to the observable physical or biochemical characteristics of an organism that result from the expression of its genes in combination with environmental influences.

It is important to note that an individual's genotype is not necessarily identical to their genetic sequence. Some genes have multiple forms called alleles, and an individual may inherit different alleles for a given gene from each parent. The combination of alleles that an individual inherits for a particular gene is known as their genotype for that gene.

Understanding an individual's genotype can provide important information about their susceptibility to certain diseases, their response to drugs and other treatments, and their risk of passing on inherited genetic disorders to their offspring.

"Genetic crosses" refer to the breeding of individuals with different genetic characteristics to produce offspring with specific combinations of traits. This process is commonly used in genetics research to study the inheritance patterns and function of specific genes.

There are several types of genetic crosses, including:

1. Monohybrid cross: A cross between two individuals that differ in the expression of a single gene or trait.
2. Dihybrid cross: A cross between two individuals that differ in the expression of two genes or traits.
3. Backcross: A cross between an individual from a hybrid population and one of its parental lines.
4. Testcross: A cross between an individual with unknown genotype and a homozygous recessive individual.
5. Reciprocal cross: A cross in which the male and female parents are reversed to determine if there is any effect of sex on the expression of the trait.

These genetic crosses help researchers to understand the mode of inheritance, linkage, recombination, and other genetic phenomena.

A nonsense codon is a sequence of three nucleotides in DNA or RNA that does not code for an amino acid. Instead, it signals the end of the protein-coding region of a gene and triggers the termination of translation, the process by which the genetic code is translated into a protein.

In DNA, the nonsense codons are UAA, UAG, and UGA, which are also known as "stop codons." When these codons are encountered during translation, they cause the release of the newly synthesized polypeptide chain from the ribosome, bringing the process of protein synthesis to a halt.

Nonsense mutations are changes in the DNA sequence that result in the appearance of a nonsense codon where an amino acid-coding codon used to be. These types of mutations can lead to premature termination of translation and the production of truncated, nonfunctional proteins, which can cause genetic diseases or contribute to cancer development.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Microcephaly is a medical condition where an individual has a smaller than average head size. The circumference of the head is significantly below the normal range for age and sex. This condition is typically caused by abnormal brain development, which can be due to genetic factors or environmental influences such as infections or exposure to harmful substances during pregnancy.

Microcephaly can be present at birth (congenital) or develop in the first few years of life. People with microcephaly often have intellectual disabilities, delayed development, and other neurological problems. However, the severity of these issues can vary widely, ranging from mild to severe. It is important to note that not all individuals with microcephaly will experience significant impairments or challenges.

Epidermolysis Bullosa Dystrophica (EBD) is a type of inherited skin disorder that belongs to the group of conditions known as Epidermolysis Bullosa. This condition is characterized by the development of fragile, blistering skin that can be caused by minor trauma or friction.

In EBD, the blisters form in the upper layer of the skin (epidermis) and the underlying layer (dermis), leading to scarring and tissue damage. The symptoms of EBD can range from mild to severe and may include:

* Blistering of the skin that can be triggered by friction, heat, or other factors
* Formation of scars, particularly on the hands and feet
* Thickening of the skin (hyperkeratosis)
* Nail abnormalities, such as ridged or brittle nails
* Mouth sores and blisters
* Dental problems, including tooth decay and gum disease

EBD is caused by mutations in the genes that provide instructions for making proteins that help to anchor the skin's layers together. As a result, the skin becomes fragile and prone to blistering.

There are several subtypes of EBD, each with its own specific genetic cause and symptoms. Treatment typically involves wound care, prevention of infection, and management of pain. In severe cases, surgery may be necessary to treat complications such as scarring or contractures.

A haplotype is a group of genes or DNA sequences that are inherited together from a single parent. It refers to a combination of alleles (variant forms of a gene) that are located on the same chromosome and are usually transmitted as a unit. Haplotypes can be useful in tracing genetic ancestry, understanding the genetic basis of diseases, and developing personalized medical treatments.

In population genetics, haplotypes are often used to study patterns of genetic variation within and between populations. By comparing haplotype frequencies across populations, researchers can infer historical events such as migrations, population expansions, and bottlenecks. Additionally, haplotypes can provide information about the evolutionary history of genes and genomic regions.

In clinical genetics, haplotypes can be used to identify genetic risk factors for diseases or to predict an individual's response to certain medications. For example, specific haplotypes in the HLA gene region have been associated with increased susceptibility to certain autoimmune diseases, while other haplotypes in the CYP450 gene family can affect how individuals metabolize drugs.

Overall, haplotypes provide a powerful tool for understanding the genetic basis of complex traits and diseases, as well as for developing personalized medical treatments based on an individual's genetic makeup.

Exons are the coding regions of DNA that remain in the mature, processed mRNA after the removal of non-coding intronic sequences during RNA splicing. These exons contain the information necessary to encode proteins, as they specify the sequence of amino acids within a polypeptide chain. The arrangement and order of exons can vary between different genes and even between different versions of the same gene (alternative splicing), allowing for the generation of multiple protein isoforms from a single gene. This complexity in exon structure and usage significantly contributes to the diversity and functionality of the proteome.

Deafness is a hearing loss that is so severe that it results in significant difficulty in understanding or comprehending speech, even when using hearing aids. It can be congenital (present at birth) or acquired later in life due to various causes such as disease, injury, infection, exposure to loud noises, or aging. Deafness can range from mild to profound and may affect one ear (unilateral) or both ears (bilateral). In some cases, deafness may be accompanied by tinnitus, which is the perception of ringing or other sounds in the ears.

Deaf individuals often use American Sign Language (ASL) or other forms of sign language to communicate. Some people with less severe hearing loss may benefit from hearing aids, cochlear implants, or other assistive listening devices. Deafness can have significant social, educational, and vocational implications, and early intervention and appropriate support services are critical for optimal development and outcomes.

Hypotrichosis is a medical term that refers to a condition characterized by an abnormal lack or sparseness of hair growth. This can apply to the eyebrows, eyelashes, or scalp hair. It's important to note that this is not a complete loss of hair, but rather a significant reduction in hair density. The onset and severity can vary greatly, and it can be inherited or acquired later in life due to various factors such as diseases, burns, or certain medications.

A frameshift mutation is a type of genetic mutation that occurs when the addition or deletion of nucleotides in a DNA sequence is not divisible by three. Since DNA is read in groups of three nucleotides (codons), which each specify an amino acid, this can shift the "reading frame," leading to the insertion or deletion of one or more amino acids in the resulting protein. This can cause a protein to be significantly different from the normal protein, often resulting in a nonfunctional protein and potentially causing disease. Frameshift mutations are typically caused by insertions or deletions of nucleotides, but they can also result from more complex genetic rearrangements.

Genetic markers are specific segments of DNA that are used in genetic mapping and genotyping to identify specific genetic locations, diseases, or traits. They can be composed of short tandem repeats (STRs), single nucleotide polymorphisms (SNPs), restriction fragment length polymorphisms (RFLPs), or variable number tandem repeats (VNTRs). These markers are useful in various fields such as genetic research, medical diagnostics, forensic science, and breeding programs. They can help to track inheritance patterns, identify genetic predispositions to diseases, and solve crimes by linking biological evidence to suspects or victims.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Intellectual disability (ID) is a term used when there are significant limitations in both intellectual functioning and adaptive behavior, which covers many everyday social and practical skills. This disability originates before the age of 18.

Intellectual functioning, also known as intelligence, refers to general mental capacity, such as learning, reasoning, problem-solving, and other cognitive skills. Adaptive behavior includes skills needed for day-to-day life, such as communication, self-care, social skills, safety judgement, and basic academic skills.

Intellectual disability is characterized by below-average intelligence or mental ability and a lack of skills necessary for day-to-day living. It can be mild, moderate, severe, or profound, depending on the degree of limitation in intellectual functioning and adaptive behavior.

It's important to note that people with intellectual disabilities have unique strengths and limitations, just like everyone else. With appropriate support and education, they can lead fulfilling lives and contribute to their communities in many ways.

Heterozygote detection is a method used in genetics to identify individuals who carry one normal and one mutated copy of a gene. These individuals are known as heterozygotes and they do not typically show symptoms of the genetic disorder associated with the mutation, but they can pass the mutated gene on to their offspring, who may then be affected.

Heterozygote detection is often used in genetic counseling and screening programs for recessive disorders such as cystic fibrosis or sickle cell anemia. By identifying heterozygotes, individuals can be informed of their carrier status and the potential risks to their offspring. This information can help them make informed decisions about family planning and reproductive options.

Various methods can be used for heterozygote detection, including polymerase chain reaction (PCR) based tests, DNA sequencing, and genetic linkage analysis. The choice of method depends on the specific gene or mutation being tested, as well as the availability and cost of the testing technology.

Genetic heterogeneity is a phenomenon in genetics where different genetic variations or mutations in various genes can result in the same or similar phenotypic characteristics, disorders, or diseases. This means that multiple genetic alterations can lead to the same clinical presentation, making it challenging to identify the specific genetic cause based on the observed symptoms alone.

There are two main types of genetic heterogeneity:

1. Allelic heterogeneity: Different mutations in the same gene can cause the same or similar disorders. For example, various mutations in the CFTR gene can lead to cystic fibrosis, a genetic disorder affecting the respiratory and digestive systems.
2. Locus heterogeneity: Mutations in different genes can result in the same or similar disorders. For instance, mutations in several genes, such as BRCA1, BRCA2, and PALB2, are associated with an increased risk of developing breast cancer.

Genetic heterogeneity is essential to consider when diagnosing genetic conditions, evaluating recurrence risks, and providing genetic counseling. It highlights the importance of comprehensive genetic testing and interpretation for accurate diagnosis and appropriate management of genetic disorders.

Ichthyosiform erythroderma, congenital, also known as Congenital Ichthyosiform Erythroderma (CIE), is a rare inherited genetic disorder of keratinization. It is characterized by widespread scaliness and erythema (redness) that are present at birth or develop soon thereafter.

The condition is caused by mutations in various genes involved in the development of the skin barrier, leading to abnormalities in the formation and shedding of skin cells. This results in a thickened, scaly appearance of the skin, which can be associated with severe dryness, irritation, and inflammation.

The symptoms of CIE can vary widely among affected individuals, ranging from mild to severe. In addition to the characteristic skin changes, some people with CIE may also experience additional features such as ectropion (outward turning of the eyelids), eclabium (splitting of the lips), and hyperkeratosis of palms and soles.

CIE is typically a lifelong condition, and treatment is focused on managing symptoms and preventing complications. This may include the use of topical moisturizers, emollients, and keratolytic agents to help soften and remove excess skin cells. In some cases, systemic medications such as retinoids may be used to help reduce the severity of skin changes.

The exome is the part of the genome that contains all the protein-coding regions. It represents less than 2% of the human genome but accounts for about 85% of disease-causing mutations. Exome sequencing, therefore, is a cost-effective and efficient method to identify genetic variants associated with various diseases, including cancer, neurological disorders, and inherited genetic conditions.

The Founder Effect is a concept in population genetics that refers to the loss of genetic variation that occurs when a new colony is established by a small number of individuals from a larger population. This decrease in genetic diversity can lead to an increase in homozygosity, which can in turn result in a higher frequency of certain genetic disorders or traits within the founding population and its descendants. The Founder Effect is named after the "founding" members of the new colony who carry and pass on their particular set of genes to the next generations. It is one of the mechanisms that can lead to the formation of distinct populations or even new species over time.

"Family Health" is not a term that has a single, widely accepted medical definition. However, in the context of healthcare and public health, "family health" often refers to the physical, mental, and social well-being of all members of a family unit. It includes the assessment, promotion, and prevention of health conditions that affect individual family members as well as the family as a whole.

Family health may also encompass interventions and programs that aim to strengthen family relationships, communication, and functioning, as these factors can have a significant impact on overall health outcomes. Additionally, family health may involve addressing social determinants of health, such as poverty, housing, and access to healthcare, which can affect the health of families and communities.

Overall, family health is a holistic approach to healthcare that recognizes the importance of considering the needs and experiences of all family members in promoting and maintaining good health.

I'm sorry for any confusion, but "Pakistan" is a country in South Asia and not a medical term or condition. If you have any medical questions or terms you would like defined, I would be happy to help!

Genetic predisposition to disease refers to an increased susceptibility or vulnerability to develop a particular illness or condition due to inheriting specific genetic variations or mutations from one's parents. These genetic factors can make it more likely for an individual to develop a certain disease, but it does not guarantee that the person will definitely get the disease. Environmental factors, lifestyle choices, and interactions between genes also play crucial roles in determining if a genetically predisposed person will actually develop the disease. It is essential to understand that having a genetic predisposition only implies a higher risk, not an inevitable outcome.

A genetic complementation test is a laboratory procedure used in molecular genetics to determine whether two mutated genes can complement each other's function, indicating that they are located at different loci and represent separate alleles. This test involves introducing a normal or wild-type copy of one gene into a cell containing a mutant version of the same gene, and then observing whether the presence of the normal gene restores the normal function of the mutated gene. If the introduction of the normal gene results in the restoration of the normal phenotype, it suggests that the two genes are located at different loci and can complement each other's function. However, if the introduction of the normal gene does not restore the normal phenotype, it suggests that the two genes are located at the same locus and represent different alleles of the same gene. This test is commonly used to map genes and identify genetic interactions in a variety of organisms, including bacteria, yeast, and animals.

Sensorineural hearing loss (SNHL) is a type of hearing impairment that occurs due to damage to the inner ear (cochlea) or to the nerve pathways from the inner ear to the brain. It can be caused by various factors such as aging, exposure to loud noises, genetics, certain medical conditions (like diabetes and heart disease), and ototoxic medications.

SNHL affects the ability of the hair cells in the cochlea to convert sound waves into electrical signals that are sent to the brain via the auditory nerve. As a result, sounds may be perceived as muffled, faint, or distorted, making it difficult to understand speech, especially in noisy environments.

SNHL is typically permanent and cannot be corrected with medication or surgery, but hearing aids or cochlear implants can help improve communication and quality of life for those affected.

The X chromosome is one of the two types of sex-determining chromosomes in humans (the other being the Y chromosome). It's one of the 23 pairs of chromosomes that make up a person's genetic material. Females typically have two copies of the X chromosome (XX), while males usually have one X and one Y chromosome (XY).

The X chromosome contains hundreds of genes that are responsible for the production of various proteins, many of which are essential for normal bodily functions. Some of the critical roles of the X chromosome include:

1. Sex Determination: The presence or absence of the Y chromosome determines whether an individual is male or female. If there is no Y chromosome, the individual will typically develop as a female.
2. Genetic Disorders: Since females have two copies of the X chromosome, they are less likely to be affected by X-linked genetic disorders than males. Males, having only one X chromosome, will express any recessive X-linked traits they inherit.
3. Dosage Compensation: To compensate for the difference in gene dosage between males and females, a process called X-inactivation occurs during female embryonic development. One of the two X chromosomes is randomly inactivated in each cell, resulting in a single functional copy per cell.

The X chromosome plays a crucial role in human genetics and development, contributing to various traits and characteristics, including sex determination and dosage compensation.

Microsatellite repeats, also known as short tandem repeats (STRs), are repetitive DNA sequences made up of units of 1-6 base pairs that are repeated in a head-to-tail manner. These repeats are spread throughout the human genome and are highly polymorphic, meaning they can have different numbers of repeat units in different individuals.

Microsatellites are useful as genetic markers because of their high degree of variability. They are commonly used in forensic science to identify individuals, in genealogy to trace ancestry, and in medical research to study genetic diseases and disorders. Mutations in microsatellite repeats have been associated with various neurological conditions, including Huntington's disease and fragile X syndrome.

Osteochondrodysplasias are a group of genetic disorders that affect the development of bones and cartilage. These conditions can result in dwarfism or short stature, as well as other skeletal abnormalities. Osteochondrodysplasias can be caused by mutations in genes that regulate bone and cartilage growth, and they are often characterized by abnormalities in the shape, size, and/or structure of the bones and cartilage.

There are many different types of osteochondrodysplasias, each with its own specific symptoms and patterns of inheritance. Some common examples include achondroplasia, thanatophoric dysplasia, and spondyloepiphyseal dysplasia. These conditions can vary in severity, and some may be associated with other health problems, such as respiratory difficulties or neurological issues.

Treatment for osteochondrodysplasias typically focuses on managing the symptoms and addressing any related health concerns. This may involve physical therapy, bracing or surgery to correct skeletal abnormalities, and treatment for any associated medical conditions. In some cases, genetic counseling may also be recommended for individuals with osteochondrodysplasias and their families.

Cerebellar ataxia is a type of ataxia, which refers to a group of disorders that cause difficulties with coordination and movement. Cerebellar ataxia specifically involves the cerebellum, which is the part of the brain responsible for maintaining balance, coordinating muscle movements, and regulating speech and eye movements.

The symptoms of cerebellar ataxia may include:

* Unsteady gait or difficulty walking
* Poor coordination of limb movements
* Tremors or shakiness, especially in the hands
* Slurred or irregular speech
* Abnormal eye movements, such as nystagmus (rapid, involuntary movement of the eyes)
* Difficulty with fine motor tasks, such as writing or buttoning a shirt

Cerebellar ataxia can be caused by a variety of underlying conditions, including:

* Genetic disorders, such as spinocerebellar ataxia or Friedreich's ataxia
* Brain injury or trauma
* Stroke or brain hemorrhage
* Infections, such as meningitis or encephalitis
* Exposure to toxins, such as alcohol or certain medications
* Tumors or other growths in the brain

Treatment for cerebellar ataxia depends on the underlying cause. In some cases, there may be no cure, and treatment is focused on managing symptoms and improving quality of life. Physical therapy, occupational therapy, and speech therapy can help improve coordination, balance, and communication skills. Medications may also be used to treat specific symptoms, such as tremors or muscle spasticity. In some cases, surgery may be recommended to remove tumors or repair damage to the brain.

Lamellar Ichthyosis is a rare, inherited genetic skin disorder characterized by widespread, persistent scaling of the skin. It is caused by mutations in genes responsible for maintaining the barrier function and hydration of the skin. The condition is present from birth and can vary in severity.

In lamellar ichthyosis, the skin cells do not shed properly and instead accumulate in plates or scales that cover the entire body. These scales are large, dark brown or gray, and have a cracked appearance, resembling fish scales. The scales may be present at birth (congenital) or develop within the first few weeks of life.

The skin is also prone to redness, irritation, and infection due to the impaired barrier function. Other symptoms can include overheating, dehydration, and difficulty with sweating. The condition may improve in warmer, more humid environments.

Treatment for lamellar ichthyosis is aimed at managing symptoms and preventing complications. This may include topical creams and ointments to moisturize the skin, medications to reduce inflammation and infection, and avoiding environmental triggers that can worsen symptoms. In some cases, oral retinoids may be prescribed to help regulate skin cell growth and shedding.

A point mutation is a type of genetic mutation where a single nucleotide base (A, T, C, or G) in DNA is altered, deleted, or substituted with another nucleotide. Point mutations can have various effects on the organism, depending on the location of the mutation and whether it affects the function of any genes. Some point mutations may not have any noticeable effect, while others might lead to changes in the amino acids that make up proteins, potentially causing diseases or altering traits. Point mutations can occur spontaneously due to errors during DNA replication or be inherited from parents.

Genetic models are theoretical frameworks used in genetics to describe and explain the inheritance patterns and genetic architecture of traits, diseases, or phenomena. These models are based on mathematical equations and statistical methods that incorporate information about gene frequencies, modes of inheritance, and the effects of environmental factors. They can be used to predict the probability of certain genetic outcomes, to understand the genetic basis of complex traits, and to inform medical management and treatment decisions.

There are several types of genetic models, including:

1. Mendelian models: These models describe the inheritance patterns of simple genetic traits that follow Mendel's laws of segregation and independent assortment. Examples include autosomal dominant, autosomal recessive, and X-linked inheritance.
2. Complex trait models: These models describe the inheritance patterns of complex traits that are influenced by multiple genes and environmental factors. Examples include heart disease, diabetes, and cancer.
3. Population genetics models: These models describe the distribution and frequency of genetic variants within populations over time. They can be used to study evolutionary processes, such as natural selection and genetic drift.
4. Quantitative genetics models: These models describe the relationship between genetic variation and phenotypic variation in continuous traits, such as height or IQ. They can be used to estimate heritability and to identify quantitative trait loci (QTLs) that contribute to trait variation.
5. Statistical genetics models: These models use statistical methods to analyze genetic data and infer the presence of genetic associations or linkage. They can be used to identify genetic risk factors for diseases or traits.

Overall, genetic models are essential tools in genetics research and medical genetics, as they allow researchers to make predictions about genetic outcomes, test hypotheses about the genetic basis of traits and diseases, and develop strategies for prevention, diagnosis, and treatment.

Dwarfism is a medical condition that is characterized by short stature, typically with an adult height of 4 feet 10 inches (147 centimeters) or less. It is caused by a variety of genetic and medical conditions that affect bone growth, including skeletal dysplasias, hormonal deficiencies, and chromosomal abnormalities.

Skeletal dysplasias are the most common cause of dwarfism and are characterized by abnormalities in the development and growth of bones and cartilage. Achondroplasia is the most common form of skeletal dysplasia, accounting for about 70% of all cases of dwarfism. It is caused by a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene and results in short limbs, a large head, and a prominent forehead.

Hormonal deficiencies, such as growth hormone deficiency or hypothyroidism, can also cause dwarfism if they are not diagnosed and treated early. Chromosomal abnormalities, such as Turner syndrome (monosomy X) or Down syndrome (trisomy 21), can also result in short stature and other features of dwarfism.

It is important to note that people with dwarfism are not "dwarves" - the term "dwarf" is a medical and sociological term used to describe individuals with this condition, while "dwarves" is a term often used in fantasy literature and media to refer to mythical beings. The use of the term "dwarf" can be considered disrespectful or offensive to some people with dwarfism, so it is important to use respectful language when referring to individuals with this condition.

Inborn genetic diseases, also known as inherited genetic disorders, are conditions caused by abnormalities in an individual's DNA that are present at conception. These abnormalities can include mutations, deletions, or rearrangements of genes or chromosomes. In many cases, these genetic changes are inherited from one or both parents and may be passed down through families.

Inborn genetic diseases can affect any part of the body and can cause a wide range of symptoms, which can vary in severity depending on the specific disorder. Some genetic disorders are caused by mutations in a single gene, while others are caused by changes in multiple genes or chromosomes. In some cases, environmental factors may also contribute to the development of these conditions.

Examples of inborn genetic diseases include cystic fibrosis, sickle cell anemia, Huntington's disease, Duchenne muscular dystrophy, and Down syndrome. These conditions can have significant impacts on an individual's health and quality of life, and many require ongoing medical management and treatment. In some cases, genetic counseling and testing may be recommended for individuals with a family history of a particular genetic disorder to help them make informed decisions about their reproductive options.

Collagen type VII is a type of collagen that is a major component of the anchoring fibrils, which are structures that help to attach the epidermis (the outermost layer of the skin) to the dermis (the layer of skin directly below the epidermis). Collagen type VII is composed of three identical chains that are encoded by the COL7A1 gene. Mutations in this gene can lead to a group of inherited blistering disorders known as autosomal recessive dystrophic epidermolysis bullosa, which is characterized by fragile skin and mucous membranes that blister and tear easily, often from minor trauma or friction.

Human chromosome pair 2 consists of two rod-shaped structures present in the nucleus of each cell of the human body. Each member of the pair contains thousands of genes and other genetic material, encoded in the form of DNA molecules. Chromosomes are the physical carriers of inheritance, and human cells typically contain 23 pairs of chromosomes for a total of 46 chromosomes.

Chromosome pair 2 is one of the autosomal pairs, meaning that it is not a sex chromosome (X or Y). Each member of chromosome pair 2 is approximately 247 million base pairs in length and contains an estimated 1,000-1,300 genes. These genes play crucial roles in various biological processes, including development, metabolism, and response to environmental stimuli.

Abnormalities in chromosome pair 2 can lead to genetic disorders, such as cat-eye syndrome (CES), which is characterized by iris abnormalities, anal atresia, hearing loss, and intellectual disability. This disorder arises from the presence of an extra copy of a small region on chromosome 2, resulting in partial trisomy of this region. Other genetic conditions associated with chromosome pair 2 include proximal 2q13.3 microdeletion syndrome and Potocki-Lupski syndrome (PTLS).

Muscular dystrophies are a group of genetic disorders that primarily affect skeletal muscles, causing progressive weakness and degeneration. They are characterized by the lack or deficiency of a protein called dystrophin, which is essential for maintaining the integrity of muscle fibers. The most common form is Duchenne muscular dystrophy (DMD), but there are many other types with varying symptoms and severity. Over time, muscle wasting and weakness can lead to disability and shortened lifespan, depending on the type and progression of the disease. Treatment typically focuses on managing symptoms, maintaining mobility, and supporting quality of life.

Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person's chance of developing or passing on a genetic disorder. Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. For example, a physician may recommend genetic testing to help diagnose a genetic condition, confirm the presence of a gene mutation known to increase the risk of developing certain cancers, or determine the chance for a couple to have a child with a genetic disorder.

There are several types of genetic tests, including:

* Diagnostic testing: This type of test is used to identify or confirm a suspected genetic condition in an individual. It may be performed before birth (prenatal testing) or at any time during a person's life.
* Predictive testing: This type of test is used to determine the likelihood that a person will develop a genetic disorder. It is typically offered to individuals who have a family history of a genetic condition but do not show any symptoms themselves.
* Carrier testing: This type of test is used to determine whether a person carries a gene mutation for a genetic disorder. It is often offered to couples who are planning to have children and have a family history of a genetic condition or belong to a population that has an increased risk of certain genetic disorders.
* Preimplantation genetic testing: This type of test is used in conjunction with in vitro fertilization (IVF) to identify genetic changes in embryos before they are implanted in the uterus. It can help couples who have a family history of a genetic disorder or who are at risk of having a child with a genetic condition to conceive a child who is free of the genetic change in question.
* Pharmacogenetic testing: This type of test is used to determine how an individual's genes may affect their response to certain medications. It can help healthcare providers choose the most effective medication and dosage for a patient, reducing the risk of adverse drug reactions.

It is important to note that genetic testing should be performed under the guidance of a qualified healthcare professional who can interpret the results and provide appropriate counseling and support.

Gene frequency, also known as allele frequency, is a measure in population genetics that reflects the proportion of a particular gene or allele (variant of a gene) in a given population. It is calculated as the number of copies of a specific allele divided by the total number of all alleles at that genetic locus in the population.

For example, if we consider a gene with two possible alleles, A and a, the gene frequency of allele A (denoted as p) can be calculated as follows:

p = (number of copies of allele A) / (total number of all alleles at that locus)

Similarly, the gene frequency of allele a (denoted as q) would be:

q = (number of copies of allele a) / (total number of all alleles at that locus)

Since there are only two possible alleles for this gene in this example, p + q = 1. These frequencies can help researchers understand genetic diversity and evolutionary processes within populations.

Single Nucleotide Polymorphism (SNP) is a type of genetic variation that occurs when a single nucleotide (A, T, C, or G) in the DNA sequence is altered. This alteration must occur in at least 1% of the population to be considered a SNP. These variations can help explain why some people are more susceptible to certain diseases than others and can also influence how an individual responds to certain medications. SNPs can serve as biological markers, helping scientists locate genes that are associated with disease. They can also provide information about an individual's ancestry and ethnic background.

Developmental bone diseases are a group of medical conditions that affect the growth and development of bones. These diseases are present at birth or develop during childhood and adolescence, when bones are growing rapidly. They can result from genetic mutations, hormonal imbalances, or environmental factors such as poor nutrition.

Some examples of developmental bone diseases include:

1. Osteogenesis imperfecta (OI): Also known as brittle bone disease, OI is a genetic disorder that affects the body's production of collagen, a protein necessary for healthy bones. People with OI have fragile bones that break easily and may also experience other symptoms such as blue sclerae (whites of the eyes), hearing loss, and joint laxity.
2. Achondroplasia: This is the most common form of dwarfism, caused by a genetic mutation that affects bone growth. People with achondroplasia have short limbs and a large head relative to their body size.
3. Rickets: A condition caused by vitamin D deficiency or an inability to absorb or use vitamin D properly. This leads to weak, soft bones that can bow or bend easily, particularly in children.
4. Fibrous dysplasia: A rare bone disorder where normal bone is replaced with fibrous tissue, leading to weakened bones and deformities.
5. Scoliosis: An abnormal curvature of the spine that can develop during childhood or adolescence. While not strictly a developmental bone disease, scoliosis can be caused by various underlying conditions such as cerebral palsy, muscular dystrophy, or spina bifida.

Treatment for developmental bone diseases varies depending on the specific condition and its severity. Treatment may include medication, physical therapy, bracing, or surgery to correct deformities and improve function. Regular follow-up with a healthcare provider is essential to monitor growth, manage symptoms, and prevent complications.

Epidermolysis Bullosa (EB) is a group of rare inherited skin disorders that are characterized by the development of blisters, erosions, and scarring following minor trauma or friction. The condition results from a genetic defect that affects the structural proteins responsible for anchoring the epidermis (outer layer of the skin) to the dermis (inner layer of the skin).

There are several types of EB, which vary in severity and clinical presentation. These include:

1. Epidermolysis Bullosa Simplex (EBS): This is the most common form of EB, and it typically affects the skin's superficial layers. Blistering tends to occur after minor trauma or friction, and healing usually occurs without scarring. There are several subtypes of EBS, which vary in severity.
2. Junctional Epidermolysis Bullosa (JEB): This form of EB affects the deeper layers of the skin, and blistering can occur spontaneously or following minor trauma. Healing often results in scarring, and affected individuals may also experience nail loss, dental abnormalities, and fragile mucous membranes.
3. Dystrophic Epidermolysis Bullosa (DEB): DEB affects the deeper layers of the skin, and blistering can lead to significant scarring, contractures, and fusion of fingers and toes. There are two main subtypes of DEB: recessive DEB (RDEB), which is more severe and associated with a higher risk of skin cancer, and dominant DEB (DDEB), which tends to be milder.
4. Kindler Syndrome: This is a rare form of EB that affects both the epidermis and dermis. Blistering can occur spontaneously or following minor trauma, and affected individuals may experience photosensitivity, poikiloderma (a mottled skin appearance), and oral and gastrointestinal abnormalities.

Treatment for EB typically focuses on managing symptoms, preventing blister formation and infection, and promoting wound healing. There is currently no cure for EB, but research is ongoing to develop new therapies and treatments.

Single-Stranded Conformational Polymorphism (SSCP) is not a medical condition but rather a laboratory technique used in molecular biology and genetics. It refers to the phenomenon where a single-stranded DNA or RNA molecule can adopt different conformations or shapes based on its nucleotide sequence, even if the difference in the sequence is as small as a single base pair change. This property is used in SSCP analysis to detect mutations or variations in DNA or RNA sequences.

In SSCP analysis, the denatured single-stranded DNA or RNA sample is subjected to electrophoresis on a non-denaturing polyacrylamide gel. The different conformations of the single-stranded molecules migrate at different rates in the gel, creating multiple bands that can be visualized by staining or other detection methods. The presence of additional bands or shifts in band patterns can indicate the presence of a sequence variant or mutation.

SSCP analysis is often used as a screening tool for genetic diseases, cancer, and infectious diseases to identify genetic variations associated with these conditions. However, it has largely been replaced by more sensitive and accurate methods such as next-generation sequencing.

Genetic polymorphism refers to the occurrence of multiple forms (called alleles) of a particular gene within a population. These variations in the DNA sequence do not generally affect the function or survival of the organism, but they can contribute to differences in traits among individuals. Genetic polymorphisms can be caused by single nucleotide changes (SNPs), insertions or deletions of DNA segments, or other types of genetic rearrangements. They are important for understanding genetic diversity and evolution, as well as for identifying genetic factors that may contribute to disease susceptibility in humans.

Hereditary eye diseases refer to conditions that affect the eyes and are passed down from parents to their offspring through genetics. These diseases are caused by mutations or changes in an individual's DNA that are inherited from their parents. The mutations can occur in any of the genes associated with eye development, function, or health.

There are many different types of hereditary eye diseases, some of which include:

1. Retinitis Pigmentosa - a group of rare, genetic disorders that involve a breakdown and loss of cells in the retina.
2. Macular Degeneration - a progressive disease that damages the central portion of the retina, impairing vision.
3. Glaucoma - a group of eye conditions that damage the optic nerve, often caused by an increase in pressure inside the eye.
4. Cataracts - clouding of the lens inside the eye, which can lead to blurry vision and blindness.
5. Keratoconus - a progressive eye disease that causes the cornea to thin and bulge outward into a cone shape.
6. Color Blindness - a condition where an individual has difficulty distinguishing between certain colors.
7. Optic Neuropathy - damage to the optic nerve, which can result in vision loss.

The symptoms and severity of hereditary eye diseases can vary widely depending on the specific condition and the individual's genetic makeup. Some conditions may be present at birth or develop in early childhood, while others may not appear until later in life. Treatment options for these conditions may include medication, surgery, or lifestyle changes, and are often most effective when started early.

Inheritance patterns refer to the way in which a particular genetic trait or disorder is passed down from one generation to the next, following the rules of Mendelian genetics. There are several different inheritance patterns, including:

1. Autosomal dominant: A single copy of the altered gene in each cell is sufficient to cause the disorder. An affected parent has a 50% chance of passing on the altered gene to each offspring.
2. Autosomal recessive: Two copies of the altered gene in each cell are necessary for the disorder to occur. Both parents must be carriers of the altered gene and have a 25% chance of passing on the altered gene to each offspring, who may then develop the disorder.
3. X-linked dominant: The altered gene is located on the X chromosome, and one copy of the altered gene in each cell is sufficient to cause the disorder. Females are more likely to be affected than males, and an affected female has a 50% chance of passing on the altered gene to each offspring.
4. X-linked recessive: The altered gene is located on the X chromosome, and two copies of the altered gene in each cell are necessary for the disorder to occur. Males are more likely to be affected than females, and an affected male will pass on the altered gene to all of his daughters (who will be carriers) but none of his sons.
5. Mitochondrial inheritance: The altered gene is located in the mitochondria, the energy-producing structures in cells. Both males and females can pass on mitochondrial genetic disorders, but only through the female line because offspring inherit their mother's mitochondria.

Understanding inheritance patterns helps medical professionals predict the likelihood of a genetic disorder occurring in families and provides information about how a disorder may be passed down through generations.

Osteopetrosis, also known as Albers-Schönberg disease or marble bone disease, is a group of rare genetic disorders characterized by increased bone density due to impaired bone resorption by osteoclasts. This results in brittle bones that are more susceptible to fractures and can also lead to various complications such as anemia, hearing loss, and vision problems. There are several types of osteopetrosis, which vary in severity and age of onset.

The medical definition of osteopetrosis is:

A genetic disorder characterized by defective bone resorption due to impaired osteoclast function, resulting in increased bone density, susceptibility to fractures, and potential complications such as anemia, hearing loss, and vision problems.

Inborn errors of metabolism (IEM) refer to a group of genetic disorders caused by defects in enzymes or transporters that play a role in the body's metabolic processes. These disorders result in the accumulation or deficiency of specific chemicals within the body, which can lead to various clinical manifestations, such as developmental delay, intellectual disability, seizures, organ damage, and in some cases, death.

Examples of IEM include phenylketonuria (PKU), maple syrup urine disease (MSUD), galactosemia, and glycogen storage diseases, among many others. These disorders are typically inherited in an autosomal recessive manner, meaning that an affected individual has two copies of the mutated gene, one from each parent.

Early diagnosis and management of IEM are crucial to prevent or minimize complications and improve outcomes. Treatment options may include dietary modifications, supplementation with missing enzymes or cofactors, medication, and in some cases, stem cell transplantation or gene therapy.

DNA Sequence Analysis is the systematic determination of the order of nucleotides in a DNA molecule. It is a critical component of modern molecular biology, genetics, and genetic engineering. The process involves determining the exact order of the four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - in a DNA molecule or fragment. This information is used in various applications such as identifying gene mutations, studying evolutionary relationships, developing molecular markers for breeding, and diagnosing genetic diseases.

The process of DNA Sequence Analysis typically involves several steps, including DNA extraction, PCR amplification (if necessary), purification, sequencing reaction, and electrophoresis. The resulting data is then analyzed using specialized software to determine the exact sequence of nucleotides.

In recent years, high-throughput DNA sequencing technologies have revolutionized the field of genomics, enabling the rapid and cost-effective sequencing of entire genomes. This has led to an explosion of genomic data and new insights into the genetic basis of many diseases and traits.

A "mutant strain of mice" in a medical context refers to genetically engineered mice that have specific genetic mutations introduced into their DNA. These mutations can be designed to mimic certain human diseases or conditions, allowing researchers to study the underlying biological mechanisms and test potential therapies in a controlled laboratory setting.

Mutant strains of mice are created through various techniques, including embryonic stem cell manipulation, gene editing technologies such as CRISPR-Cas9, and radiation-induced mutagenesis. These methods allow scientists to introduce specific genetic changes into the mouse genome, resulting in mice that exhibit altered physiological or behavioral traits.

These strains of mice are widely used in biomedical research because their short lifespan, small size, and high reproductive rate make them an ideal model organism for studying human diseases. Additionally, the mouse genome has been well-characterized, and many genetic tools and resources are available to researchers working with these animals.

Examples of mutant strains of mice include those that carry mutations in genes associated with cancer, neurodegenerative disorders, metabolic diseases, and immunological conditions. These mice provide valuable insights into the pathophysiology of human diseases and help advance our understanding of potential therapeutic interventions.

The term "Arabs" is a cultural and linguistic designation, rather than a racial or genetic one. It refers to individuals who speak Arabic as their native language and share a common cultural and historical heritage that is rooted in the Arabian Peninsula. The Arabic language and culture have spread throughout North Africa, the Middle East, and other parts of the world through conquest, trade, and migration over many centuries.

It's important to note that there is significant genetic diversity within the Arab population, just as there is in any large and geographically dispersed group of people. Therefore, it would not be accurate or appropriate to use the term "Arabs" to make assumptions about an individual's genetic background or ancestry.

In medical contexts, it is more appropriate to use specific geographic or ethnic designations (such as "Saudi Arabian," "Lebanese," "North African," etc.) rather than the broad cultural label of "Arab." This can help ensure greater accuracy and precision in describing a patient's background and health risks.

Eye proteins, also known as ocular proteins, are specific proteins that are found within the eye and play crucial roles in maintaining proper eye function and health. These proteins can be found in various parts of the eye, including the cornea, iris, lens, retina, and other structures. They perform a wide range of functions, such as:

1. Structural support: Proteins like collagen and elastin provide strength and flexibility to the eye's tissues, enabling them to maintain their shape and withstand mechanical stress.
2. Light absorption and transmission: Proteins like opsins and crystallins are involved in capturing and transmitting light signals within the eye, which is essential for vision.
3. Protection against damage: Some eye proteins, such as antioxidant enzymes and heat shock proteins, help protect the eye from oxidative stress, UV radiation, and other environmental factors that can cause damage.
4. Regulation of eye growth and development: Various growth factors and signaling molecules, which are protein-based, contribute to the proper growth, differentiation, and maintenance of eye tissues during embryonic development and throughout adulthood.
5. Immune defense: Proteins involved in the immune response, such as complement components and immunoglobulins, help protect the eye from infection and inflammation.
6. Maintenance of transparency: Crystallin proteins in the lens maintain its transparency, allowing light to pass through unobstructed for clear vision.
7. Neuroprotection: Certain eye proteins, like brain-derived neurotrophic factor (BDNF), support the survival and function of neurons within the retina, helping to preserve vision.

Dysfunction or damage to these eye proteins can contribute to various eye disorders and diseases, such as cataracts, age-related macular degeneration, glaucoma, diabetic retinopathy, and others.

Genetic suppression is a concept in genetics that refers to the phenomenon where the expression or function of one gene is reduced or silenced by another gene. This can occur through various mechanisms such as:

* Allelic exclusion: When only one allele (version) of a gene is expressed, while the other is suppressed.
* Epigenetic modifications: Chemical changes to the DNA or histone proteins that package DNA can result in the suppression of gene expression.
* RNA interference: Small RNAs can bind to and degrade specific mRNAs (messenger RNAs), preventing their translation into proteins.
* Transcriptional repression: Proteins called transcription factors can bind to DNA and prevent the recruitment of RNA polymerase, which is necessary for gene transcription.

Genetic suppression plays a crucial role in regulating gene expression and maintaining proper cellular function. It can also contribute to diseases such as cancer when genes that suppress tumor growth are suppressed themselves.

Human chromosome pair 1 refers to the first pair of chromosomes in a set of 23 pairs found in the cells of the human body, excluding sex cells (sperm and eggs). Each cell in the human body, except for the gametes, contains 46 chromosomes arranged in 23 pairs. These chromosomes are rod-shaped structures that contain genetic information in the form of DNA.

Chromosome pair 1 is the largest pair, making up about 8% of the total DNA in a cell. Each chromosome in the pair consists of two arms - a shorter p arm and a longer q arm - connected at a centromere. Chromosome 1 carries an estimated 2,000-2,500 genes, which are segments of DNA that contain instructions for making proteins or regulating gene expression.

Defects or mutations in the genes located on chromosome 1 can lead to various genetic disorders and diseases, such as Charcot-Marie-Tooth disease type 1A, Huntington's disease, and certain types of cancer.

Myotonia Congenita is a genetic muscle disorder characterized by delayed relaxation after voluntary muscle contraction, leading to stiffness or difficulty in relaxing the muscles following use. This muscle stiffness is called myotonia and can be aggravated by voluntary muscle action, such as handgrip or walking, and also occurs after periods of rest.

There are two main forms of Myotonia Congenita: Thomsen's disease (autosomal dominant inheritance) and Becker's disease (autosomal recessive inheritance). The disorder is caused by mutations in the CLCN1 gene, which encodes a chloride channel that helps regulate muscle excitability.

Myotonia Congenita primarily affects skeletal muscles, causing stiffness and cramping, but it does not typically affect muscle strength or size. Symptoms usually begin in childhood and may improve with repeated muscle use (warm-up phenomenon). Treatment options include medication to reduce muscle stiffness and physical therapy to maintain muscle flexibility and strength.

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

The "age of onset" is a medical term that refers to the age at which an individual first develops or displays symptoms of a particular disease, disorder, or condition. It can be used to describe various medical conditions, including both physical and mental health disorders. The age of onset can have implications for prognosis, treatment approaches, and potential causes of the condition. In some cases, early onset may indicate a more severe or progressive course of the disease, while late-onset symptoms might be associated with different underlying factors or etiologies. It is essential to provide accurate and precise information regarding the age of onset when discussing a patient's medical history and treatment plan.

Charcot-Marie-Tooth disease (CMT) is a group of inherited disorders that cause nerve damage, primarily affecting the peripheral nerves. These are the nerves that transmit signals between the brain and spinal cord to the rest of the body. CMT affects both motor and sensory nerves, leading to muscle weakness and atrophy, as well as numbness or tingling in the hands and feet.

The disease is named after the three physicians who first described it: Jean-Martin Charcot, Pierre Marie, and Howard Henry Tooth. CMT is characterized by its progressive nature, meaning symptoms typically worsen over time, although the rate of progression can vary significantly among individuals.

There are several types of CMT, classified based on their genetic causes and patterns of inheritance. The two most common forms are CMT1 and CMT2:

1. CMT1: This form is caused by mutations in the genes responsible for the myelin sheath, which insulates peripheral nerves and allows for efficient signal transmission. As a result, demyelination occurs, slowing down nerve impulses and causing muscle weakness, particularly in the lower limbs. Symptoms usually begin in childhood or adolescence and include foot drop, high arches, and hammertoes.
2. CMT2: This form is caused by mutations in the genes responsible for the axons, the nerve fibers that transmit signals within peripheral nerves. As a result, axonal degeneration occurs, leading to muscle weakness and atrophy. Symptoms usually begin in early adulthood and progress more slowly than CMT1. They primarily affect the lower limbs but can also involve the hands and arms.

Diagnosis of CMT typically involves a combination of clinical evaluation, family history, nerve conduction studies, and genetic testing. While there is no cure for CMT, treatment focuses on managing symptoms and maintaining mobility and function through physical therapy, bracing, orthopedic surgery, and pain management.

A sequence deletion in a genetic context refers to the removal or absence of one or more nucleotides (the building blocks of DNA or RNA) from a specific region in a DNA or RNA molecule. This type of mutation can lead to the loss of genetic information, potentially resulting in changes in the function or expression of a gene. If the deletion involves a critical portion of the gene, it can cause diseases, depending on the role of that gene in the body. The size of the deleted sequence can vary, ranging from a single nucleotide to a large segment of DNA.

Hearing loss is a partial or total inability to hear sounds in one or both ears. It can occur due to damage to the structures of the ear, including the outer ear, middle ear, inner ear, or nerve pathways that transmit sound to the brain. The degree of hearing loss can vary from mild (difficulty hearing soft sounds) to severe (inability to hear even loud sounds). Hearing loss can be temporary or permanent and may be caused by factors such as exposure to loud noises, genetics, aging, infections, trauma, or certain medical conditions. It is important to note that hearing loss can have significant impacts on a person's communication abilities, social interactions, and overall quality of life.

Ectodermal dysplasia (ED) is a group of genetic disorders that affect the development and formation of ectodermal tissues, which include the skin, hair, nails, teeth, and sweat glands. The condition is usually present at birth or appears in early infancy.

The symptoms of ED can vary widely depending on the specific type and severity of the disorder. Common features may include:

* Sparse or absent hair
* Thin, wrinkled, or rough skin
* Abnormal or missing teeth
* Nail abnormalities
* Absent or reduced sweat glands, leading to heat intolerance and problems regulating body temperature
* Ear abnormalities, which can result in hearing loss
* Eye abnormalities

ED is caused by mutations in genes that are involved in the development of ectodermal tissues. Most cases of ED are inherited in an autosomal dominant or autosomal recessive pattern, meaning that a child can inherit the disorder even if only one parent (dominant) or both parents (recessive) carry the mutated gene.

There is no cure for ED, but treatment is focused on managing the symptoms and improving quality of life. This may include measures to maintain body temperature, such as cooling vests or frequent cool baths; dental treatments to replace missing teeth; hearing aids for hearing loss; and skin care regimens to prevent dryness and irritation.

Friedreich Ataxia is a genetic disorder that affects the nervous system and causes issues with movement. It is characterized by progressive damage to the nerves (neurons) in the spinal cord and peripheral nerves, which can lead to problems with muscle coordination, gait, speech, and hearing. The condition is also associated with heart disorders, diabetes, and vision impairment.

Friedreich Ataxia is caused by a mutation in the FXN gene, which provides instructions for making a protein called frataxin. This protein plays a role in the production of energy within cells, particularly in the mitochondria. The mutation in the FXN gene leads to reduced levels of frataxin, which can cause nerve damage and other symptoms associated with Friedreich Ataxia.

The condition typically begins in childhood or early adulthood and progresses over time, often leading to significant disability. There is currently no cure for Friedreich Ataxia, but treatments are available to help manage the symptoms and improve quality of life.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

Electroretinography (ERG) is a medical test used to evaluate the functioning of the retina, which is the light-sensitive tissue located at the back of the eye. The test measures the electrical responses of the retina to light stimulation.

During the procedure, a special contact lens or electrode is placed on the surface of the eye to record the electrical activity generated by the retina's light-sensitive cells (rods and cones) and other cells in the retina. The test typically involves presenting different levels of flashes of light to the eye while the electrical responses are recorded.

The resulting ERG waveform provides information about the overall health and function of the retina, including the condition of the photoreceptors, the integrity of the inner retinal layers, and the health of the retinal ganglion cells. This test is often used to diagnose and monitor various retinal disorders, such as retinitis pigmentosa, macular degeneration, and diabetic retinopathy.

Dysostosis is a term used to describe a group of genetic disorders that are characterized by abnormal development and formation of one or more bones in the body. The condition is typically present at birth (congenital) and can affect any bone, but it most commonly involves the bones of the skull, face, hands, and feet.

The term "dysostosis" comes from the Greek words "dys," meaning difficult or abnormal, and "osteon," meaning bone. Dysostoses are usually caused by mutations in specific genes that regulate bone development. These genetic changes can be inherited from one or both parents or can occur spontaneously during fetal development.

There are many different types of dysostoses, each with its own set of symptoms and characteristics. Some common examples include:

1. Cleidocranial Dysplasia: This is a rare genetic disorder that affects the development of the skull and collarbones (cleido). People with cleidocranial dysplasia may have a larger than normal head, wide-set eyes, a prominent forehead, and underdeveloped or missing collarbones.
2. Acrocephalopolysyndactyly Type II: Also known as ACPS II or Greig cephalopolysyndactyly syndrome, this disorder is characterized by a pointed skull (acrocephaly), extra fingers and toes (polydactyly), and wide-set eyes.
3. Osteogenesis Imperfecta: This is a group of genetic disorders that affect the body's production of collagen, a protein that helps to strengthen bones. People with osteogenesis imperfecta have fragile bones that break easily, often as a result of minor trauma.
4. Diastrophic Dysplasia: This is a rare genetic disorder that affects the development of the bones and cartilage in the body. People with diastrophic dysplasia may have short limbs, a deformed spine, and a characteristic "hitchhiker's thumb" appearance.
5. Thanatophoric Dysplasia: This is a severe genetic disorder that affects the development of the bones in the body. People with thanatophoric dysplasia have very short limbs, a small chest, and a deformed skull. The condition is often fatal in infancy or early childhood.

These are just a few examples of the many different types of skeletal dysplasias that exist. While some forms of these disorders can be managed with medical treatment and therapy, others may require surgery or other interventions to help improve quality of life. In some cases, genetic counseling and testing may be recommended for individuals who are considering starting a family and have a history of skeletal dysplasia in their family.

Ethyl methanesulfonate (EMS) is an alkylating agent that is commonly used as a mutagen in genetic research. It works by introducing point mutations into the DNA of organisms, which can then be studied to understand the function of specific genes. EMS modifies DNA by transferring an ethyl group (-C2H5) to the oxygen atom of guanine bases, leading to mispairing during DNA replication and resulting in a high frequency of GC to AT transitions. It is highly toxic and mutagenic, and appropriate safety precautions must be taken when handling this chemical.

A newborn infant is a baby who is within the first 28 days of life. This period is also referred to as the neonatal period. Newborns require specialized care and attention due to their immature bodily systems and increased vulnerability to various health issues. They are closely monitored for signs of well-being, growth, and development during this critical time.

Chromosome disorders are a group of genetic conditions caused by abnormalities in the number or structure of chromosomes. Chromosomes are thread-like structures located in the nucleus of cells that contain most of the body's genetic material, which is composed of DNA and proteins. Normally, humans have 23 pairs of chromosomes, for a total of 46 chromosomes.

Chromosome disorders can result from changes in the number of chromosomes (aneuploidy) or structural abnormalities in one or more chromosomes. Some common examples of chromosome disorders include:

1. Down syndrome: a condition caused by an extra copy of chromosome 21, resulting in intellectual disability, developmental delays, and distinctive physical features.
2. Turner syndrome: a condition that affects only females and is caused by the absence of all or part of one X chromosome, resulting in short stature, lack of sexual development, and other symptoms.
3. Klinefelter syndrome: a condition that affects only males and is caused by an extra copy of the X chromosome, resulting in tall stature, infertility, and other symptoms.
4. Cri-du-chat syndrome: a condition caused by a deletion of part of the short arm of chromosome 5, resulting in intellectual disability, developmental delays, and a distinctive cat-like cry.
5. Fragile X syndrome: a condition caused by a mutation in the FMR1 gene on the X chromosome, resulting in intellectual disability, behavioral problems, and physical symptoms.

Chromosome disorders can be diagnosed through various genetic tests, such as karyotyping, chromosomal microarray analysis (CMA), or fluorescence in situ hybridization (FISH). Treatment for these conditions depends on the specific disorder and its associated symptoms and may include medical interventions, therapies, and educational support.

Medical definitions of "malformed nails" may vary, but generally, it refers to a condition where the nails are abnormally formed or shaped. This can include various deformities such as:

1. Koilonychia: Also known as "spoon nails," where the nails appear scooped out and concave.
2. Pterygium: A condition where skin grows over the nail, causing it to adhere to the finger.
3. Onychogryphosis: Also known as "ram's horn nails," where the nails become thick, curved, and overgrown.
4. Brachyonychia: Shortened nails that do not grow normally.
5. Onychauxis: Thickening of the nails.
6. Leukonychia: White spots or lines on the nails.
7. Beau's lines: Indentations across the nails, often caused by a previous illness or injury.
8. Pitting: Small depressions or holes in the nails.
9. Cracking or splitting of the nails.

These nail abnormalities can be caused by various factors such as genetics, fungal infections, trauma, nutritional deficiencies, and underlying medical conditions.

The term "family" in a medical context often refers to a group of individuals who are related by blood, marriage, or adoption and who consider themselves to be a single household. This can include spouses, parents, children, siblings, grandparents, and other extended family members. In some cases, the term may also be used more broadly to refer to any close-knit group of people who provide emotional and social support for one another, regardless of their biological or legal relationship.

In healthcare settings, understanding a patient's family dynamics can be important for providing effective care. Family members may be involved in decision-making about medical treatments, providing care and support at home, and communicating with healthcare providers. Additionally, cultural beliefs and values within families can influence health behaviors and attitudes towards medical care, making it essential for healthcare professionals to take a culturally sensitive approach when working with patients and their families.

Retinal degeneration is a broad term that refers to the progressive loss of photoreceptor cells (rods and cones) in the retina, which are responsible for converting light into electrical signals that are sent to the brain. This process can lead to vision loss or blindness. There are many different types of retinal degeneration, including age-related macular degeneration, retinitis pigmentosa, and Stargardt's disease, among others. These conditions can have varying causes, such as genetic mutations, environmental factors, or a combination of both. Treatment options vary depending on the specific type and progression of the condition.

Pigmentation, in a medical context, refers to the coloring of the skin, hair, or eyes due to the presence of pigment-producing cells called melanocytes. These cells produce a pigment called melanin, which determines the color of our skin, hair, and eyes.

There are two main types of melanin: eumelanin and pheomelanin. Eumelanin is responsible for brown or black coloration, while pheomelanin produces a red or yellow hue. The amount and type of melanin produced by melanocytes can vary from person to person, leading to differences in skin color and hair color.

Changes in pigmentation can occur due to various factors such as genetics, exposure to sunlight, hormonal changes, inflammation, or certain medical conditions. For example, hyperpigmentation refers to an excess production of melanin that results in darkened patches on the skin, while hypopigmentation is a condition where there is a decreased production of melanin leading to lighter or white patches on the skin.

Oculocutaneous albinism (OCA) is a group of genetic disorders characterized by reduced or complete absence of melanin pigment in the eyes, skin, and hair. Melanin is the pigment responsible for giving color to our skin, hair, and eyes. OCA affects both the eyes (oculo-) and the skin (cutaneous), hence the name oculocutaneous albinism.

There are several types of OCA, each caused by different genetic mutations affecting melanin production. The most common forms include:

1. OCA1: This type is further divided into two subtypes - OCA1A and OCA1B. OCA1A is characterized by complete absence of melanin in the eyes, skin, and hair from birth. Individuals with this condition have white hair, very light skin, and pale blue or gray irises. OCA1B, on the other hand, presents with reduced melanin production, leading to lighter-than-average skin, hair, and eye color at birth. Over time, some melanin may be produced, resulting in milder pigmentation changes compared to OCA1A.
2. OCA2: This form of albinism is caused by mutations in the tyrosinase-related protein 1 (TYRP1) gene, which plays a role in melanin production. Individuals with OCA2 typically have light brown or yellowish skin, golden or straw-colored hair, and lighter irises compared to their family members without albinism.
3. OCA3: Also known as Rufous oculocutaneous albinism (ROCA), this type is caused by mutations in the tyrosinase gene (TYR). It primarily affects people of African descent, leading to reddish-brown hair, light brown skin, and normal or near-normal eye color.
4. OCA4: This form of albinism results from mutations in the membrane-associated transporter protein (MATP) gene, which is involved in melanin transport within cells. Individuals with OCA4 usually have light brown skin, yellowish or blond hair, and lighter irises compared to their family members without albinism.

Regardless of the type, all individuals with oculocutaneous albinism face similar challenges, including reduced vision due to abnormal eye development (nystagmus, strabismus, and farsightedness) and increased sensitivity to sunlight (photophobia). Proper management, such as wearing UV-protective sunglasses, hats, and sunscreen, can help protect their skin and eyes from damage.

I'm sorry for any confusion, but "Jews" is not a medical term. It is a term used to describe a group of people who share cultural, religious, and ethnic heritage. The Jewish people originated from the ancient kingdoms of Israel and Judah. They are bound together by their religion, Judaism, which is based on the Torah, or the five books of Moses.

If you have any medical questions or terms that you would like defined, I'd be happy to help!

Microphthalmos is a medical condition where one or both eyes are abnormally small due to developmental anomalies in the eye. The size of the eye may vary from slightly smaller than normal to barely visible. This condition can occur in isolation or as part of a syndrome with other congenital abnormalities. It can also be associated with other ocular conditions such as cataracts, retinal disorders, and orbital defects. Depending on the severity, microphthalmos may lead to visual impairment or blindness.

Arthrogryposis is a medical term that describes a condition characterized by the presence of multiple joint contractures at birth. A contracture occurs when the range of motion in a joint is limited, making it difficult or impossible to move the joint through its full range of motion. In arthrogryposis, these contractures are present in two or more areas of the body.

The term "arthrogryposis" comes from two Greek words: "arthro," meaning joint, and "gyros," meaning curved or bent. Therefore, arthrogryposis literally means "curving of the joints."

There are many different types of arthrogryposis, each with its own specific set of symptoms and causes. However, in general, arthrogryposis is caused by decreased fetal movement during pregnancy, which can be due to a variety of factors such as genetic mutations, nervous system abnormalities, or environmental factors that restrict fetal movement.

Treatment for arthrogryposis typically involves a combination of physical therapy, bracing, and surgery to help improve joint mobility and function. The prognosis for individuals with arthrogryposis varies depending on the severity and type of contractures present, as well as the underlying cause of the condition.

Syndactyly is a congenital condition where two or more digits (fingers or toes) are fused together. It can occur in either the hand or foot, and it can involve fingers or toes on both sides of the hand or foot. The fusion can be partial, where only the skin is connected, or complete, where the bones are also connected. Syndactyly is usually noticed at birth and can be associated with other genetic conditions or syndromes. Surgical intervention may be required to separate the digits and improve function and appearance.

Cutis laxa is a group of rare connective tissue disorders characterized by loose, sagging, and inelastic skin. The term "cutis laxa" comes from Latin, meaning "loose skin." This condition can affect both the skin and the internal organs. Inherited forms of cutis laxa are caused by mutations in various genes involved in the structure and function of connective tissue, while acquired forms can be associated with autoimmune disorders, cancer, or certain medications.

The main features of cutis laxa include:

1. Sagging, redundant skin: The skin appears loose and wrinkled, especially on the face, neck, hands, and feet. This is due to a deficiency in elastic fibers, which provide flexibility and resilience to the skin.
2. Premature aging appearance: The sagging skin can give an individual a prematurely aged appearance, with deep wrinkles and folds around the eyes, mouth, and neck.
3. Pulmonary involvement: Recurrent respiratory infections, bronchiectasis (permanent enlargement of the airways), and emphysema can occur due to weakened lung tissue.
4. Gastrointestinal issues: Weakened intestinal walls may lead to hernias, bowel obstructions, or malabsorption.
5. Cardiovascular problems: The aorta and other major blood vessels may become weakened and dilated, leading to an increased risk of aneurysms and dissections (tears in the vessel wall).
6. Ophthalmic complications: Eye abnormalities such as blue sclerae (transparent blue appearance of the whites of the eyes) and strabismus (crossed eyes) can occur.
7. Skeletal abnormalities: Individuals with cutis laxa may have joint hypermobility, scoliosis (curvature of the spine), or hip dislocations.
8. Neurological issues: Rarely, cutis laxa can be associated with developmental delays, intellectual disability, or seizures.

There is no cure for cutis laxa, and treatment focuses on managing symptoms and preventing complications. This may include skin care, physical therapy, medications to control blood pressure, and surgery to repair hernias or aneurysms. Regular follow-up with a multidisciplinary team of healthcare professionals is essential to monitor disease progression and address any emerging issues.

Ethylnitrosourea (ENU) is an alkylating agent, which is a type of chemical compound that has the ability to interact with and modify the structure of DNA. It is commonly used in laboratory research as a mutagen, which is a substance that increases the frequency of mutations or changes in the genetic material of organisms.

ENU is known to cause point mutations, which are small changes in the DNA sequence that can lead to alterations in the function of genes. This property makes ENU a valuable tool for studying gene function and for creating animal models of human diseases caused by genetic mutations.

It is important to note that ENU is a potent carcinogen, meaning it can cause cancer, and should be handled with care in laboratory settings. It is not used as a medical treatment in humans or animals.

Cystic kidney diseases are a group of genetic disorders that cause fluid-filled sacs called cysts to form in the kidneys. These cysts can vary in size and can grow over time, which can lead to damage in the kidneys and affect their function. There are two main types of cystic kidney diseases: autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD).

ADPKD is the most common type and is characterized by the presence of numerous cysts in both kidneys. It is usually diagnosed in adulthood, but it can also occur in children. The cysts can cause high blood pressure, kidney stones, urinary tract infections, and eventually kidney failure.

ARPKD is a rare, inherited disorder that affects both the kidneys and liver. It is characterized by the presence of numerous cysts in the kidneys and abnormalities in the bile ducts of the liver. ARPKD is usually diagnosed in infancy or early childhood and can cause serious complications such as respiratory distress, kidney failure, and liver fibrosis.

Other types of cystic kidney diseases include nephronophthisis, medullary cystic kidney disease, and glomerulocystic kidney disease. These conditions are also inherited and can cause kidney damage and kidney failure.

Treatment for cystic kidney diseases typically involves managing symptoms such as high blood pressure, pain, and infections. In some cases, surgery may be necessary to remove large cysts or to treat complications such as kidney stones. For individuals with advanced kidney disease, dialysis or a kidney transplant may be necessary.

Genetic association studies are a type of epidemiological research that aims to identify statistical associations between genetic variations and particular traits or diseases. These studies typically compare the frequency of specific genetic markers, such as single nucleotide polymorphisms (SNPs), in individuals with a given trait or disease to those without it.

The goal of genetic association studies is to identify genetic factors that contribute to the risk of developing common complex diseases, such as diabetes, heart disease, or cancer. By identifying these genetic associations, researchers hope to gain insights into the underlying biological mechanisms of these diseases and develop new strategies for prevention, diagnosis, and treatment.

It's important to note that while genetic association studies can identify statistical associations between genetic markers and traits or diseases, they cannot prove causality. Further research is needed to confirm and validate these findings and to understand the functional consequences of the identified genetic variants.

Spinal muscular atrophy (SMA) is a genetic disorder that affects the motor neurons in the spinal cord, leading to muscle weakness and atrophy. It is caused by a mutation in the survival motor neuron 1 (SMN1) gene, which results in a deficiency of SMN protein necessary for the survival of motor neurons.

There are several types of SMA, classified based on the age of onset and severity of symptoms. The most common type is type 1, also known as Werdnig-Hoffmann disease, which presents in infancy and is characterized by severe muscle weakness, hypotonia, and feeding difficulties. Other types include type 2 (intermediate SMA), type 3 (Kugelberg-Welander disease), and type 4 (adult-onset SMA).

The symptoms of SMA may include muscle wasting, fasciculations, weakness, hypotonia, respiratory difficulties, and mobility impairment. The diagnosis of SMA typically involves genetic testing to confirm the presence of a mutation in the SMN1 gene. Treatment options for SMA may include medications, physical therapy, assistive devices, and respiratory support.

Eye abnormalities refer to any structural or functional anomalies that affect the eye or its surrounding tissues. These abnormalities can be present at birth (congenital) or acquired later in life due to various factors such as injury, disease, or aging. Some examples of eye abnormalities include:

1. Strabismus: Also known as crossed eyes, strabismus is a condition where the eyes are misaligned and point in different directions.
2. Nystagmus: This is an involuntary movement of the eyes that can be horizontal, vertical, or rotatory.
3. Cataracts: A cataract is a clouding of the lens inside the eye that can cause vision loss.
4. Glaucoma: This is a group of eye conditions that damage the optic nerve and can lead to vision loss.
5. Retinal disorders: These include conditions such as retinal detachment, macular degeneration, and diabetic retinopathy.
6. Corneal abnormalities: These include conditions such as keratoconus, corneal ulcers, and Fuchs' dystrophy.
7. Orbital abnormalities: These include conditions such as orbital tumors, thyroid eye disease, and Graves' ophthalmopathy.
8. Ptosis: This is a condition where the upper eyelid droops over the eye.
9. Color blindness: A condition where a person has difficulty distinguishing between certain colors.
10. Microphthalmia: A condition where one or both eyes are abnormally small.

These are just a few examples of eye abnormalities, and there are many others that can affect the eye and its functioning. If you suspect that you have an eye abnormality, it is important to consult with an ophthalmologist for proper diagnosis and treatment.

Renal tubular acidosis (RTA) is a medical condition that occurs when the kidneys are unable to properly excrete acid into the urine, leading to an accumulation of acid in the bloodstream. This results in a state of metabolic acidosis.

There are several types of RTA, but renal tubular acidosis type 1 (also known as distal RTA) is characterized by a defect in the ability of the distal tubules to acidify the urine, leading to an inability to lower the pH of the urine below 5.5, even in the face of metabolic acidosis. This results in a persistently alkaline urine, which can lead to calcium phosphate stones and bone demineralization.

Type 1 RTA is often caused by inherited genetic defects, but it can also be acquired due to various kidney diseases, drugs, or autoimmune disorders. Symptoms of type 1 RTA may include fatigue, weakness, muscle cramps, decreased appetite, and vomiting. Treatment typically involves alkali therapy to correct the acidosis and prevent complications.

Congenital foot deformities refer to abnormal structural changes in the foot that are present at birth. These deformities can vary from mild to severe and may affect the shape, position, or function of one or both feet. Common examples include clubfoot (talipes equinovarus), congenital vertical talus, and cavus foot. Congenital foot deformities can be caused by genetic factors, environmental influences during fetal development, or a combination of both. Treatment options may include stretching, casting, surgery, or a combination of these approaches, depending on the severity and type of the deformity.

Hair diseases is a broad term that refers to various medical conditions affecting the hair shaft, follicle, or scalp. These conditions can be categorized into several types, including:

1. Hair shaft abnormalities: These are conditions that affect the structure and growth of the hair shaft. Examples include trichorrhexis nodosa, where the hair becomes weak and breaks easily, and pili torti, where the hair shaft is twisted and appears sparse and fragile.
2. Hair follicle disorders: These are conditions that affect the hair follicles, leading to hair loss or abnormal growth patterns. Examples include alopecia areata, an autoimmune disorder that causes patchy hair loss, and androgenetic alopecia, a genetic condition that leads to pattern baldness in both men and women.
3. Scalp disorders: These are conditions that affect the scalp, leading to symptoms such as itching, redness, scaling, or pain. Examples include seborrheic dermatitis, psoriasis, and tinea capitis (ringworm of the scalp).
4. Hair cycle abnormalities: These are conditions that affect the normal growth cycle of the hair, leading to excessive shedding or thinning. Examples include telogen effluvium, where a large number of hairs enter the resting phase and fall out, and anagen effluvium, which is typically caused by chemotherapy or radiation therapy.
5. Infectious diseases: Hair follicles can become infected with various bacteria, viruses, or fungi, leading to conditions such as folliculitis, furunculosis, and kerion.
6. Genetic disorders: Some genetic disorders can affect the hair, such as Menkes syndrome, which is a rare inherited disorder that affects copper metabolism and leads to kinky, sparse, and brittle hair.

Proper diagnosis and treatment of hair diseases require consultation with a healthcare professional, often a dermatologist or a trichologist who specializes in hair and scalp disorders.

Hereditary Sensory and Autonomic Neuropathies (HSANs) are a group of inherited disorders that affect the sensory and autonomic nerves. These nerves are responsible for transmitting information about senses such as touch, pain, temperature, and vibration to the brain, as well as controlling automatic functions like blood pressure, heart rate, and digestion.

HSANs are caused by genetic mutations that result in damage to the peripheral nerves. There are several types of HSANs, each with its own specific symptoms and patterns of inheritance. Some common features include:

* Loss of sensation in the hands and feet
* Pain insensitivity
* Absent or reduced reflexes
* Autonomic dysfunction, such as abnormal sweating, blood pressure regulation, and digestive problems

The severity and progression of HSANs can vary widely depending on the specific type and individual factors. Treatment is generally focused on managing symptoms and preventing complications, such as injuries from lack of pain sensation or falls due to balance problems. Early diagnosis and intervention are important for optimizing outcomes.

Inborn errors of amino acid metabolism refer to genetic disorders that affect the body's ability to properly break down and process individual amino acids, which are the building blocks of proteins. These disorders can result in an accumulation of toxic levels of certain amino acids or their byproducts in the body, leading to a variety of symptoms and health complications.

There are many different types of inborn errors of amino acid metabolism, each affecting a specific amino acid or group of amino acids. Some examples include:

* Phenylketonuria (PKU): This disorder affects the breakdown of the amino acid phenylalanine, leading to its accumulation in the body and causing brain damage if left untreated.
* Maple syrup urine disease: This disorder affects the breakdown of the branched-chain amino acids leucine, isoleucine, and valine, leading to their accumulation in the body and causing neurological problems.
* Homocystinuria: This disorder affects the breakdown of the amino acid methionine, leading to its accumulation in the body and causing a range of symptoms including developmental delay, intellectual disability, and cardiovascular problems.

Treatment for inborn errors of amino acid metabolism typically involves dietary restrictions or supplementation to manage the levels of affected amino acids in the body. In some cases, medication or other therapies may also be necessary. Early diagnosis and treatment can help prevent or minimize the severity of symptoms and health complications associated with these disorders.

Hereditary Spastic Paraplegia (HSP) is a group of genetic disorders that affect the long motor neurons in the spinal cord, leading to lower limb spasticity and weakness. It is characterized by progressive stiffness and contraction of the leg muscles, resulting in difficulty with walking and balance.

The symptoms of HSP typically begin in childhood or early adulthood and worsen over time. The severity of the condition can vary widely, even within the same family, depending on the specific genetic mutation involved. In addition to lower limb spasticity, some individuals with HSP may also experience bladder dysfunction, sensory loss, or other neurological symptoms.

HSP is inherited in an autosomal dominant or autosomal recessive pattern, depending on the specific genetic mutation involved. There are over 70 different genes that have been identified as causing HSP, and genetic testing can be used to confirm the diagnosis and identify the specific genetic mutation responsible.

Treatment for HSP is focused on managing symptoms and maintaining mobility. Physical therapy, orthotics, and medications such as baclofen or tizanidine may be used to help reduce muscle spasticity and improve mobility. In some cases, surgery may be necessary to relieve muscle contractures or other complications.

X-linked genetic diseases refer to a group of disorders caused by mutations in genes located on the X chromosome. These conditions primarily affect males since they have only one X chromosome and therefore don't have a second normal copy of the gene to compensate for the mutated one. Females, who have two X chromosomes, are typically less affected because they usually have one normal copy of the gene on their other X chromosome.

Examples of X-linked genetic diseases include Duchenne and Becker muscular dystrophy, hemophilia A and B, color blindness, and fragile X syndrome. Symptoms and severity can vary widely depending on the specific condition and the nature of the genetic mutation involved. Treatment options depend on the particular disease but may include physical therapy, medication, or in some cases, gene therapy.

Sarcoglycans are a group of proteins that are part of the dystrophin-glycoprotein complex in muscle cells. This complex helps to maintain the structural integrity of the muscle fiber by forming a link between the cytoskeleton and the extracellular matrix. Sarcoglycans are located on the surface of the muscle fiber and play a critical role in protecting the muscle from damage during contraction.

There are four main sarcoglycans, known as alpha, beta, gamma, and delta-sarcoglycan. Mutations in any one of these proteins can lead to a group of genetic disorders known as the sarcoglycanopathies, which are characterized by progressive muscle weakness and wasting. The most severe form of this disorder is called limb-girdle muscular dystrophy type 2C (LGMD2C), which is caused by mutations in the gamma-sarcoglycan gene.

In addition to their role in muscle cells, sarcoglycans have also been found to be expressed in other tissues, including the brain and the lungs, suggesting that they may have additional functions beyond their structural role in muscle.

Polycystic Kidney Disease (PKD) is a genetic disorder characterized by the growth of multiple cysts in the kidneys. These cysts are fluid-filled sacs that can vary in size and can multiply, leading to enlarged kidneys. The increased size and number of cysts can result in reduced kidney function, high blood pressure, and eventually kidney failure.

There are two main types of PKD: Autosomal Dominant Polycystic Kidney Disease (ADPKD) and Autosomal Recessive Polycystic Kidney Disease (ARPKD). ADPKD is the most common form, affecting approximately 1 in every 500 people. It typically develops in adulthood. On the other hand, ARPKD is a rarer form, affecting about 1 in every 20,000 children, and it often presents in infancy or early childhood.

In addition to kidney problems, PKD can also affect other organs, such as the liver and the heart. It's important to note that while there is no cure for PKD, various treatments can help manage symptoms and slow down the progression of the disease.

Survival of Motor Neuron 1 (SMN1) protein is a critical component for the survival of motor neurons, which are nerve cells that control muscle movements. The SMN1 protein is produced by the Survival of Motor Neuron 1 gene, located on human chromosome 5q13.

The primary function of the SMN1 protein is to assist in the biogenesis of small nuclear ribonucleoproteins (snRNPs), which are essential for spliceosomes - complex molecular machines responsible for RNA processing in the cell. The absence or significant reduction of SMN1 protein leads to defective snRNP assembly, impaired RNA splicing, and ultimately results in motor neuron degeneration.

Mutations in the SMN1 gene can cause Spinal Muscular Atrophy (SMA), a genetic disorder characterized by progressive muscle weakness, atrophy, and paralysis due to the loss of lower motor neurons in the spinal cord. The severity of SMA depends on the amount of functional SMN1 protein produced, with less protein leading to more severe symptoms.

A gene in plants, like in other organisms, is a hereditary unit that carries genetic information from one generation to the next. It is a segment of DNA (deoxyribonucleic acid) that contains the instructions for the development and function of an organism. Genes in plants determine various traits such as flower color, plant height, resistance to diseases, and many others. They are responsible for encoding proteins and RNA molecules that play crucial roles in the growth, development, and reproduction of plants. Plant genes can be manipulated through traditional breeding methods or genetic engineering techniques to improve crop yield, enhance disease resistance, and increase nutritional value.

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

Cystinosis is a rare, inherited metabolic disorder that affects primarily the eyes, kidneys, and liver. It is characterized by an abnormal accumulation of the amino acid cystine within lysosomes (cellular organelles responsible for breaking down and recycling waste products) due to a defect in the gene CTNS that encodes for a protein called cystinosin. This leads to the formation of crystals, which can cause cell damage and multi-organ dysfunction.

There are three main types of cystinosis:

1. Nephropathic or infantile cystinosis: This is the most severe form, with symptoms appearing within the first year of life. It primarily affects the kidneys, leading to Fanconi syndrome (a condition characterized by excessive loss of nutrients in urine), growth failure, and kidney dysfunction. If left untreated, it can progress to end-stage renal disease (ESRD) around the age of 10.
2. Intermediate cystinosis: This form presents during childhood with milder kidney involvement but can still lead to ESRD in adolescence or early adulthood. Eye and central nervous system abnormalities may also be present.
3. Non-nephropathic or ocular cystinosis: This is the mildest form, primarily affecting the eyes. Symptoms include photophobia (sensitivity to light), corneal opacities, and decreased vision. Kidney function remains normal in this type.

Treatment for cystinosis typically involves a combination of medications to manage symptoms and slow disease progression. Cysteamine therapy, which helps remove excess cystine from cells, is the primary treatment for all types of cystinosis. Regular monitoring and management of complications are essential to maintain quality of life and prolong survival.

Penetrance, in medical genetics, refers to the proportion of individuals with a particular genetic variant or mutation who exhibit clinical features or symptoms of a resulting disease. It is often expressed as a percentage, with complete penetrance indicating that all individuals with the genetic change will develop the disease, and reduced or incomplete penetrance suggesting that not all individuals with the genetic change will necessarily develop the disease, even if they express some of its characteristics.

Penetrance can vary depending on various factors such as age, sex, environmental influences, and interactions with other genes. Incomplete penetrance is common in many genetic disorders, making it challenging to predict who will develop symptoms based solely on their genotype.

Optic atrophy is a medical term that refers to the degeneration and shrinkage (atrophy) of the optic nerve, which transmits visual information from the eye to the brain. This condition can result in various vision abnormalities, including loss of visual acuity, color vision deficiencies, and peripheral vision loss.

Optic atrophy can occur due to a variety of causes, such as:

* Traumatic injuries to the eye or optic nerve
* Glaucoma
* Optic neuritis (inflammation of the optic nerve)
* Ischemic optic neuropathy (reduced blood flow to the optic nerve)
* Compression or swelling of the optic nerve
* Hereditary or congenital conditions affecting the optic nerve
* Toxins and certain medications that can damage the optic nerve.

The diagnosis of optic atrophy typically involves a comprehensive eye examination, including visual acuity testing, refraction assessment, slit-lamp examination, and dilated funduscopic examination to evaluate the health of the optic nerve. In some cases, additional diagnostic tests such as visual field testing, optical coherence tomography (OCT), or magnetic resonance imaging (MRI) may be necessary to confirm the diagnosis and determine the underlying cause.

There is no specific treatment for optic atrophy, but addressing the underlying cause can help prevent further damage to the optic nerve. In some cases, vision rehabilitation may be recommended to help patients adapt to their visual impairment.

"Facies" is a medical term that refers to the typical appearance of a person or part of the body, particularly the face, which may provide clues about their underlying medical condition or genetic background. A specific facies is often associated with certain syndromes or disorders. For example, a "downsyndrome facies" refers to the distinctive facial features commonly found in individuals with Down syndrome, such as a flattened nasal bridge, almond-shaped eyes, and an upward slant to the eyelids.

It's important to note that while facies can provide valuable diagnostic information, it should be used in conjunction with other clinical findings and genetic testing to make a definitive diagnosis. Additionally, facies should be described objectively and without judgment, as they are simply physical characteristics associated with certain medical conditions.

I'm sorry for any confusion, but "Tunisia" is not a medical term. It is actually the name of a country located in North Africa, known for its rich history, beautiful coastline, and vibrant culture. If you have any questions about medical terms or if there's another topic you'd like to know more about, please let me know!

Muscle hypotonia, also known as decreased muscle tone, refers to a condition where the muscles appear to be flaccid or lacking in tension and stiffness. This results in reduced resistance to passive movements, making the limbs feel "floppy" or "like a rag doll." It can affect any muscle group in the body and can be caused by various medical conditions, including neurological disorders, genetic diseases, and injuries to the nervous system. Hypotonia should not be confused with muscle weakness, which refers to the inability to generate normal muscle strength.

Fanconi anemia is a rare, inherited disorder that affects the body's ability to produce healthy blood cells. It is characterized by bone marrow failure, congenital abnormalities, and an increased risk of developing certain types of cancer. The condition is caused by mutations in genes responsible for repairing damaged DNA, leading to chromosomal instability and cell death.

The classic form of Fanconi anemia (type A) is typically diagnosed in childhood and is associated with various physical abnormalities such as short stature, skin pigmentation changes, thumb and radial ray anomalies, kidney and genitourinary malformations, and developmental delays. Other types of Fanconi anemia (B-G) may have different clinical presentations but share the common feature of bone marrow failure and cancer predisposition.

Bone marrow failure in Fanconi anemia results in decreased production of all three types of blood cells: red blood cells, white blood cells, and platelets. This can lead to anemia (low red blood cell count), neutropenia (low white blood cell count), and thrombocytopenia (low platelet count). These conditions increase the risk of infections, fatigue, and bleeding.

Individuals with Fanconi anemia have a significantly higher risk of developing various types of cancer, particularly acute myeloid leukemia (AML) and solid tumors such as squamous cell carcinomas of the head, neck, esophagus, and anogenital region.

Treatment for Fanconi anemia typically involves managing symptoms related to bone marrow failure, such as transfusions, growth factors, and antibiotics. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment option for bone marrow failure but carries risks of its own, including graft-versus-host disease and transplant-related mortality. Regular cancer surveillance is essential due to the increased risk of malignancies in these patients.

'Drosophila melanogaster' is the scientific name for a species of fruit fly that is commonly used as a model organism in various fields of biological research, including genetics, developmental biology, and evolutionary biology. Its small size, short generation time, large number of offspring, and ease of cultivation make it an ideal subject for laboratory studies. The fruit fly's genome has been fully sequenced, and many of its genes have counterparts in the human genome, which facilitates the understanding of genetic mechanisms and their role in human health and disease.

Here is a brief medical definition:

Drosophila melanogaster (droh-suh-fih-luh meh-lon-guh-ster): A species of fruit fly used extensively as a model organism in genetic, developmental, and evolutionary research. Its genome has been sequenced, revealing many genes with human counterparts, making it valuable for understanding genetic mechanisms and their role in human health and disease.

Keratoderma, palmoplantar is a medical term that refers to a group of skin conditions characterized by thickening and hardening (hyperkeratosis) of the skin on the palms of the hands and soles of the feet. This condition can affect people of all ages, but it's most commonly seen in children.

The thickening of the skin is caused by an overproduction of keratin, a protein that helps to form the tough, outer layer of the skin. In palmoplantar keratoderma, this excess keratin accumulates in the stratum corneum, the outermost layer of the epidermis, leading to the formation of rough, scaly, and thickened patches on the palms and soles.

There are several different types of palmoplantar keratoderma, each with its own specific symptoms and causes. Some forms of the condition are inherited and present at birth or develop in early childhood, while others may be acquired later in life as a result of an underlying medical condition, such as atopic dermatitis, lichen planus, or psoriasis.

Treatment for palmoplantar keratoderma typically involves the use of emollients and keratolytic agents to help soften and remove the thickened skin. In some cases, oral retinoids or other systemic medications may be necessary to manage more severe symptoms. It's important to consult with a healthcare provider for an accurate diagnosis and treatment plan.

I'm sorry for any confusion, but "hair color" is not a term that has a medical definition in the same way that a term like "myocardial infarction" (heart attack) does. Hair color can be described in various ways, such as being a natural hair color (like blonde, brunette, red, or black) or describing a change in hair color due to factors like aging (gray or white hairs) or hair dye usage.

However, it's worth noting that changes in hair color can sometimes be associated with certain medical conditions. For example, premature graying of the hair before the age of 30 can be a feature of certain genetic disorders or vitamin B12 deficiency. Similarly, some skin conditions like alopecia areata or vitiligo can cause patchy changes in hair color. But these associations don't provide a medical definition for 'hair color'.

Sex chromosome aberrations refer to structural and numerical abnormalities in the sex chromosomes, which are typically represented as X and Y chromosomes in humans. These aberrations can result in variations in the number of sex chromosomes, such as Klinefelter syndrome (47,XXY), Turner syndrome (45,X), and Jacobs/XYY syndrome (47,XYY). They can also include structural changes, such as deletions, duplications, or translocations of sex chromosome material.

Sex chromosome aberrations may lead to a range of phenotypic effects, including differences in physical characteristics, cognitive development, fertility, and susceptibility to certain health conditions. The manifestation and severity of these impacts can vary widely depending on the specific type and extent of the aberration, as well as individual genetic factors and environmental influences.

It is important to note that while sex chromosome aberrations may pose challenges and require medical management, they do not inherently define or limit a person's potential, identity, or worth. Comprehensive care, support, and education can help individuals with sex chromosome aberrations lead fulfilling lives and reach their full potential.

Human chromosome pair 16 consists of two rod-shaped structures present in the nucleus of each cell in the human body. Each chromosome is made up of DNA tightly coiled around histone proteins, forming a complex structure called a chromatin.

Chromosomes come in pairs, with one chromosome inherited from each parent. Chromosome pair 16 contains two homologous chromosomes, which are similar in size, shape, and genetic content but may have slight variations due to differences in the DNA sequences inherited from each parent.

Chromosome pair 16 is one of the 22 autosomal pairs, meaning it contains non-sex chromosomes that are present in both males and females. Chromosome 16 is a medium-sized chromosome, and it contains around 2,800 genes that provide instructions for making proteins and regulating various cellular processes.

Abnormalities in chromosome pair 16 can lead to genetic disorders such as chronic myeloid leukemia, some forms of mental retardation, and other developmental abnormalities.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

Gene deletion is a type of mutation where a segment of DNA, containing one or more genes, is permanently lost or removed from a chromosome. This can occur due to various genetic mechanisms such as homologous recombination, non-homologous end joining, or other types of genomic rearrangements.

The deletion of a gene can have varying effects on the organism, depending on the function of the deleted gene and its importance for normal physiological processes. If the deleted gene is essential for survival, the deletion may result in embryonic lethality or developmental abnormalities. However, if the gene is non-essential or has redundant functions, the deletion may not have any noticeable effects on the organism's phenotype.

Gene deletions can also be used as a tool in genetic research to study the function of specific genes and their role in various biological processes. For example, researchers may use gene deletion techniques to create genetically modified animal models to investigate the impact of gene deletion on disease progression or development.

Craniofacial abnormalities refer to a group of birth defects that affect the development of the skull and face. These abnormalities can range from mild to severe and may involve differences in the shape and structure of the head, face, and jaws, as well as issues with the formation of facial features such as the eyes, nose, and mouth.

Craniofacial abnormalities can be caused by genetic factors, environmental influences, or a combination of both. Some common examples of craniofacial abnormalities include cleft lip and palate, craniosynostosis (premature fusion of the skull bones), and hemifacial microsomia (underdevelopment of one side of the face).

Treatment for craniofacial abnormalities may involve a team of healthcare professionals, including plastic surgeons, neurosurgeons, orthodontists, speech therapists, and other specialists. Treatment options may include surgery, bracing, therapy, and other interventions to help improve function and appearance.

Mutagenesis is the process by which the genetic material (DNA or RNA) of an organism is changed in a way that can alter its phenotype, or observable traits. These changes, known as mutations, can be caused by various factors such as chemicals, radiation, or viruses. Some mutations may have no effect on the organism, while others can cause harm, including diseases and cancer. Mutagenesis is a crucial area of study in genetics and molecular biology, with implications for understanding evolution, genetic disorders, and the development of new medical treatments.

Night blindness, also known as nyctalopia, is a visual impairment characterized by the inability to see well in low light or darkness. It's not an eye condition itself but rather a symptom of various underlying eye disorders, most commonly vitamin A deficiency and retinal diseases like retinitis pigmentosa.

In a healthy eye, a molecule called rhodopsin is present in the rods (special light-sensitive cells in our eyes responsible for vision in low light conditions). This rhodopsin requires sufficient amounts of vitamin A to function properly. When there's a deficiency of vitamin A or damage to the rods, the ability to see in dim light gets affected, leading to night blindness.

People with night blindness often have difficulty adjusting to changes in light levels, such as when entering a dark room from bright sunlight. They may also experience trouble seeing stars at night, driving at dusk or dawn, and navigating in poorly lit areas. If you suspect night blindness, it's essential to consult an eye care professional for proper diagnosis and treatment of the underlying cause.

Genetic load is a term used in population genetics that refers to the reduction in average fitness (or reproductive success) of a population due to the presence of deleterious or harmful alleles (versions of genes). These alleles can negatively impact an individual's survival, reproduction, or both. Genetic load can be caused by various factors such as mutations, genetic drift, and selection.

There are several types of genetic load, including:

1. Mutation load: The decrease in fitness due to the accumulation of new deleterious mutations in a population over time.
2. Segregation load: The reduction in average fitness caused by the presence of recessive deleterious alleles that are hidden in heterozygotes (individuals with one normal and one deleterious allele).
3. Inbreeding load: The decrease in fitness due to an increase in homozygosity (the presence of identical alleles on both chromosomes) resulting from inbreeding, which exposes recessive deleterious alleles.
4. Genetic drift load: The reduction in fitness caused by the random loss of beneficial or neutral alleles due to genetic drift, leading to a decrease in genetic diversity and an increase in the frequency of deleterious alleles.
5. Coevolutionary load: The decline in fitness resulting from the disruption of coadapted gene complexes (combinations of interacting genes) when populations are separated or experience environmental changes.

Overall, genetic load represents the cost of maintaining genetic variation within a population and can impact its long-term evolutionary potential and adaptability to changing environments.

The term "Asian Continental Ancestry Group" is a medical/ethnic classification used to describe a person's genetic background and ancestry. According to this categorization, individuals with origins in the Asian continent are grouped together. This includes populations from regions such as East Asia (e.g., China, Japan, Korea), South Asia (e.g., India, Pakistan, Bangladesh), Southeast Asia (e.g., Philippines, Indonesia, Thailand), and Central Asia (e.g., Kazakhstan, Uzbekistan, Tajikistan). It is important to note that this broad categorization may not fully capture the genetic diversity within these regions or accurately reflect an individual's specific ancestral origins.

Muscular diseases, also known as myopathies, refer to a group of conditions that affect the functionality and health of muscle tissue. These diseases can be inherited or acquired and may result from inflammation, infection, injury, or degenerative processes. They can cause symptoms such as weakness, stiffness, cramping, spasms, wasting, and loss of muscle function.

Examples of muscular diseases include:

1. Duchenne Muscular Dystrophy (DMD): A genetic disorder that results in progressive muscle weakness and degeneration due to a lack of dystrophin protein.
2. Myasthenia Gravis: An autoimmune disease that causes muscle weakness and fatigue, typically affecting the eyes and face, throat, and limbs.
3. Inclusion Body Myositis (IBM): A progressive muscle disorder characterized by muscle inflammation and wasting, typically affecting older adults.
4. Polymyositis: An inflammatory myopathy that causes muscle weakness and inflammation throughout the body.
5. Metabolic Myopathies: A group of inherited disorders that affect muscle metabolism, leading to exercise intolerance, muscle weakness, and other symptoms.
6. Muscular Dystonias: Involuntary muscle contractions and spasms that can cause abnormal postures or movements.

It is important to note that muscular diseases can have a significant impact on an individual's quality of life, mobility, and overall health. Proper diagnosis and treatment are crucial for managing symptoms and improving outcomes.

Inbreeding, in a medical context, refers to the practice of mating closely related individuals within a given family or breeding population. This leads to an increased proportion of homozygous genes, meaning that the same alleles (versions of a gene) are inherited from both parents. As a result, recessive traits and disorders become more likely to be expressed because the necessary dominant allele may be absent.

In human medicine, consanguinity is the term often used instead of inbreeding, and it refers to relationships between individuals who share a common ancestor. Consanguinity increases the risk of certain genetic disorders due to the increased likelihood of sharing harmful recessive genes. The closer the relationship, the higher the risk.

In animal breeding, inbreeding can lead to reduced fertility, lower birth weights, higher infant mortality, and a decreased lifespan. It is crucial to maintain genetic diversity within populations to ensure their overall health and vigor.

Congenital limb deformities refer to abnormalities in the structure, position, or function of the arms or legs that are present at birth. These deformities can vary greatly in severity and may affect any part of the limb, including the bones, muscles, joints, and nerves.

Congenital limb deformities can be caused by genetic factors, exposure to certain medications or chemicals during pregnancy, or other environmental factors. Some common types of congenital limb deformities include:

1. Clubfoot: A condition in which the foot is twisted out of shape, making it difficult to walk normally.
2. Polydactyly: A condition in which a person is born with extra fingers or toes.
3. Radial clubhand: A rare condition in which the radius bone in the forearm is missing or underdeveloped, causing the hand to turn inward and the wrist to bend.
4. Amniotic band syndrome: A condition in which strands of the amniotic sac wrap around a developing limb, restricting its growth and leading to deformities.
5. Agenesis: A condition in which a limb or part of a limb is missing at birth.

Treatment for congenital limb deformities may include surgery, bracing, physical therapy, or other interventions depending on the severity and nature of the deformity. In some cases, early intervention and treatment can help to improve function and reduce the impact of the deformity on a person's daily life.

Introns are non-coding sequences of DNA that are present within the genes of eukaryotic organisms, including plants, animals, and humans. Introns are removed during the process of RNA splicing, in which the initial RNA transcript is cut and reconnected to form a mature, functional RNA molecule.

After the intron sequences are removed, the remaining coding sequences, known as exons, are joined together to create a continuous stretch of genetic information that can be translated into a protein or used to produce non-coding RNAs with specific functions. The removal of introns allows for greater flexibility in gene expression and regulation, enabling the generation of multiple proteins from a single gene through alternative splicing.

In summary, introns are non-coding DNA sequences within genes that are removed during RNA processing to create functional RNA molecules or proteins.

I'm sorry for any confusion, but "Lebanon" is not a medical term. It is the name of a country located in the Middle East, known officially as the Lebanese Republic. If you have any questions about medical conditions or terms, please provide them, and I would be happy to help.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

Ataxia is a medical term that refers to a group of disorders affecting coordination, balance, and speech. It is characterized by a lack of muscle control during voluntary movements, causing unsteady or awkward movements, and often accompanied by tremors. Ataxia can affect various parts of the body, such as the limbs, trunk, eyes, and speech muscles. The condition can be congenital or acquired, and it can result from damage to the cerebellum, spinal cord, or sensory nerves. There are several types of ataxia, including hereditary ataxias, degenerative ataxias, cerebellar ataxias, and acquired ataxias, each with its own specific causes, symptoms, and prognosis. Treatment for ataxia typically focuses on managing symptoms and improving quality of life, as there is no cure for most forms of the disorder.

Congenital hand deformities refer to physical abnormalities or malformations of the hand, wrist, and/or digits (fingers) that are present at birth. These deformities can result from genetic factors, environmental influences during pregnancy, or a combination of both. They may affect the bones, muscles, tendons, joints, and other structures in the hand, leading to varying degrees of impairment in function and appearance.

There are numerous types of congenital hand deformities, some of which include:

1. Polydactyly: The presence of extra digits on the hand, which can be fully formed or rudimentary.
2. Syndactyly: Webbing or fusion of two or more fingers, which may involve soft tissue only or bone as well.
3. Clinodactyly: A curved finger due to a sideways deviation of the fingertip, often affecting the little finger.
4. Camptodactyly: Permanent flexion or bending of one or more fingers, typically involving the proximal interphalangeal joint.
5. Trigger Finger/Thumb: A condition where a finger or thumb becomes locked in a bent position due to thickening and narrowing of the tendon sheath.
6. Radial Club Hand (Radial Ray Deficiency): Underdevelopment or absence of the radius bone, resulting in a short, curved forearm and hand deformity.
7. Ulnar Club Hand (Ulnar Ray Deficiency): Underdevelopment or absence of the ulna bone, leading to a short, curved forearm and hand deformity.
8. Cleidocranial Dysplasia: A genetic disorder affecting bone growth, resulting in underdeveloped or absent collarbones, dental abnormalities, and occasionally hand deformities.
9. Apert Syndrome: A rare genetic disorder characterized by the fusion of fingers and toes (syndactyly) and other skeletal abnormalities.
10. Holt-Oram Syndrome: A genetic disorder involving heart defects and upper limb deformities, such as radial ray deficiency or thumb anomalies.

Treatment for hand deformities varies depending on the specific condition and severity. Options may include physical therapy, bracing, splinting, medications, or surgical intervention.

Human chromosome pair 19 refers to a group of 19 identical chromosomes that are present in every cell of the human body, except for the sperm and egg cells which contain only 23 chromosomes. Chromosomes are thread-like structures that carry genetic information in the form of DNA (deoxyribonucleic acid) molecules.

Each chromosome is made up of two arms, a shorter p arm and a longer q arm, separated by a centromere. Human chromosome pair 19 is an acrocentric chromosome, which means that the centromere is located very close to the end of the short arm (p arm).

Chromosome pair 19 contains approximately 58 million base pairs of DNA and encodes for around 1,400 genes. It is one of the most gene-dense chromosomes in the human genome, with many genes involved in important biological processes such as metabolism, immunity, and neurological function.

Abnormalities in chromosome pair 19 have been associated with various genetic disorders, including Sotos syndrome, which is characterized by overgrowth, developmental delay, and distinctive facial features, and Smith-Magenis syndrome, which is marked by intellectual disability, behavioral problems, and distinct physical features.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

An amino acid substitution is a type of mutation in which one amino acid in a protein is replaced by another. This occurs when there is a change in the DNA sequence that codes for a particular amino acid in a protein. The genetic code is redundant, meaning that most amino acids are encoded by more than one codon (a sequence of three nucleotides). As a result, a single base pair change in the DNA sequence may not necessarily lead to an amino acid substitution. However, if a change does occur, it can have a variety of effects on the protein's structure and function, depending on the nature of the substituted amino acids. Some substitutions may be harmless, while others may alter the protein's activity or stability, leading to disease.

In medical terms, the skin is the largest organ of the human body. It consists of two main layers: the epidermis (outer layer) and dermis (inner layer), as well as accessory structures like hair follicles, sweat glands, and oil glands. The skin plays a crucial role in protecting us from external factors such as bacteria, viruses, and environmental hazards, while also regulating body temperature and enabling the sense of touch.

Parkinsonian disorders are a group of neurological conditions characterized by motor symptoms such as bradykinesia (slowness of movement), rigidity, resting tremor, and postural instability. These symptoms are caused by the degeneration of dopamine-producing neurons in the brain, particularly in the substantia nigra pars compacta.

The most common Parkinsonian disorder is Parkinson's disease (PD), which is a progressive neurodegenerative disorder. However, there are also several other secondary Parkinsonian disorders, including:

1. Drug-induced parkinsonism: This is caused by the use of certain medications, such as antipsychotics and metoclopramide.
2. Vascular parkinsonism: This is caused by small vessel disease in the brain, which can lead to similar symptoms as PD.
3. Dementia with Lewy bodies (DLB): This is a type of dementia that shares some features with PD, such as the presence of alpha-synuclein protein clumps called Lewy bodies.
4. Progressive supranuclear palsy (PSP): This is a rare brain disorder that affects movement, gait, and eye movements.
5. Multiple system atrophy (MSA): This is a progressive neurodegenerative disorder that affects multiple systems in the body, including the autonomic nervous system, motor system, and cerebellum.
6. Corticobasal degeneration (CBD): This is a rare neurological disorder that affects both movement and cognition.

It's important to note that while these disorders share some symptoms with PD, they have different underlying causes and may require different treatments.

Spinal muscular atrophies (SMAs) of childhood are a group of inherited neuromuscular disorders characterized by degeneration and loss of lower motor neurons in the spinal cord, leading to progressive muscle weakness and atrophy. The severity and age of onset can vary significantly, with some forms presenting in infancy and others in later childhood or even adulthood.

The most common form of SMA is 5q autosomal recessive SMA, also known as survival motor neuron (SMN) disease, which results from mutations in the SMN1 gene. The severity of this form can range from severe (type I or Werdnig-Hoffmann disease), intermediate (type II or chronic infantile neurodegenerative disorder), to mild (type III or Kugelberg-Welander disease).

Type I SMA is the most severe form, with onset before 6 months of age and rapid progression leading to death within the first two years of life if left untreated. Type II SMA has an onset between 6 and 18 months of age, with affected children never achieving the ability to walk independently. Type III SMA has a later onset, typically after 18 months of age, and is characterized by a slower progression, allowing for the ability to walk unaided, although mobility may be lost over time.

Other forms of childhood-onset SMA include autosomal dominant distal SMA, X-linked SMA, and spinal bulbar muscular atrophy (SBMA or Kennedy's disease). These forms have distinct genetic causes and clinical presentations.

In general, SMAs are characterized by muscle weakness, hypotonia, fasciculations, tongue atrophy, and depressed or absent deep tendon reflexes. Respiratory and nutritional support is often required in more severe cases. Recent advances in gene therapy have led to the development of disease-modifying treatments for some forms of SMA.

RNA splice sites are specific sequences on the pre-messenger RNA (pre-mRNA) molecule where the splicing process occurs during gene expression in eukaryotic cells. The pre-mRNA contains introns and exons, which are non-coding and coding regions of the RNA, respectively.

The splicing process removes the introns and joins together the exons to form a mature mRNA molecule that can be translated into a protein. The splice sites are recognized by the spliceosome, a complex of proteins and small nuclear RNAs (snRNAs) that catalyze the splicing reaction.

There are two main types of splice sites: the 5' splice site and the 3' splice site. The 5' splice site is located at the junction between the 5' end of the intron and the 3' end of the exon, while the 3' splice site is located at the junction between the 3' end of the intron and the 5' end of the exon.

The 5' splice site contains a conserved GU sequence, while the 3' splice site contains a conserved AG sequence. These sequences are recognized by the snRNAs in the spliceosome, which bind to them and facilitate the splicing reaction.

Mutations or variations in RNA splice sites can lead to abnormal splicing and result in diseases such as cancer, neurodegenerative disorders, and genetic disorders.

Bardet-Biedl Syndrome (BBD) is a rare genetic disorder that affects multiple organs and systems in the body. It is characterized by a combination of symptoms including:

1. Obesity: Excessive weight gain, especially around the trunk and face, is a common feature of BBS.
2. Polydactyly: Extra fingers or toes are present at birth in about 70% of individuals with BBS.
3. Retinal degeneration: Progressive loss of vision due to retinal dystrophy is a hallmark of the syndrome.
4. Renal abnormalities: Structural and functional kidney problems, such as cysts, nephronophthisis, and chronic kidney disease, are common in BBS patients.
5. Learning difficulties: Intellectual disability or developmental delay is often present in individuals with BBS.
6. Hypogonadism: Abnormalities of the reproductive system, such as small genitals, delayed puberty, and infertility, are common in both males and females with BBS.
7. Other features: Additional symptoms may include speech and language delay, behavioral problems, diabetes mellitus, heart defects, and hearing loss.

Bardet-Biedl Syndrome is inherited as an autosomal recessive trait, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to develop the syndrome. The disorder affects both males and females equally and has a prevalence of about 1 in 100,000-160,000 individuals worldwide.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

Osteogenesis Imperfecta (OI), also known as brittle bone disease, is a group of genetic disorders that mainly affect the bones. It is characterized by bones that break easily, often from little or no apparent cause. This happens because the body produces an insufficient amount of collagen or poor quality collagen, which are crucial for the formation of healthy bones.

The severity of OI can vary greatly, even within the same family. Some people with OI have only a few fractures in their lifetime while others may have hundreds. Other symptoms can include blue or gray sclera (the white part of the eye), hearing loss, short stature, curved or bowed bones, loose joints, and a triangular face shape.

There are several types of OI, each caused by different genetic mutations. Most types of OI are inherited in an autosomal dominant pattern, meaning only one copy of the altered gene is needed to cause the condition. However, some types are inherited in an autosomal recessive pattern, which means that two copies of the altered gene must be present for the condition to occur.

There is no cure for OI, but treatment can help manage symptoms and prevent complications. Treatment may include medication to strengthen bones, physical therapy, bracing, and surgery.

Human chromosome pair 6 consists of two rod-shaped structures present in the nucleus of each human cell. They are identical in size and shape and contain genetic material, made up of DNA and proteins, that is essential for the development and function of the human body.

Chromosome pair 6 is one of the 23 pairs of chromosomes found in humans, with one chromosome inherited from each parent. Each chromosome contains thousands of genes that provide instructions for the production of proteins and regulate various cellular processes.

Chromosome pair 6 contains several important genes, including those involved in the development and function of the immune system, such as the major histocompatibility complex (MHC) genes. It also contains genes associated with certain genetic disorders, such as hereditary neuropathy with liability to pressure palsies (HNPP), a condition that affects the nerves, and Waardenburg syndrome, a disorder that affects pigmentation and hearing.

Abnormalities in chromosome pair 6 can lead to various genetic disorders, including numerical abnormalities such as trisomy 6 (three copies of chromosome 6) or monosomy 6 (only one copy of chromosome 6), as well as structural abnormalities such as deletions, duplications, or translocations of parts of the chromosome.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

Ubiquitin-protein ligases, also known as E3 ubiquitin ligases, are a group of enzymes that play a crucial role in the ubiquitination process. Ubiquitination is a post-translational modification where ubiquitin molecules are attached to specific target proteins, marking them for degradation by the proteasome or for other regulatory functions.

Ubiquitin-protein ligases catalyze the final step in this process by binding to both the ubiquitin protein and the target protein, facilitating the transfer of ubiquitin from an E2 ubiquitin-conjugating enzyme to the target protein. There are several different types of ubiquitin-protein ligases, each with their own specificity for particular target proteins and regulatory functions.

Ubiquitin-protein ligases have been implicated in various cellular processes such as protein degradation, DNA repair, signal transduction, and regulation of the cell cycle. Dysregulation of ubiquitination has been associated with several diseases, including cancer, neurodegenerative disorders, and inflammatory responses. Therefore, understanding the function and regulation of ubiquitin-protein ligases is an important area of research in biology and medicine.

The Survival Motor Neuron (SMN) complex is a protein complex that plays a crucial role in the biogenesis of small nuclear ribonucleoproteins (snRNPs), which are essential components of the spliceosome involved in pre-messenger RNA (pre-mRNA) splicing. The SMN complex consists of several proteins, including the SMN protein itself, Gemins2-8, and unrip.

The SMN protein is the central component of the complex and is encoded by the SMN1 gene located on chromosome 5q13.2. Mutations in this gene can lead to spinal muscular atrophy (SMA), a genetic disorder characterized by degeneration of motor neurons in the spinal cord, leading to muscle weakness and atrophy.

The SMN complex assembles in the cytoplasm and facilitates the assembly of spliceosomal snRNPs by helping to load Sm proteins onto small nuclear RNA (snRNA) molecules. Proper functioning of the SMN complex is essential for the correct splicing of pre-mRNA, and its dysfunction can lead to various developmental abnormalities and diseases, including SMA.

A cataract is a clouding of the natural lens in the eye that affects vision. This clouding can cause vision to become blurry, faded, or dim, making it difficult to see clearly. Cataracts are a common age-related condition, but they can also be caused by injury, disease, or medication use. In most cases, cataracts develop gradually over time and can be treated with surgery to remove the cloudy lens and replace it with an artificial one.

Tooth abnormalities refer to any variations or irregularities in the size, shape, number, structure, or development of teeth that deviate from the typical or normal anatomy. These abnormalities can occur in primary (deciduous) or permanent teeth and can be caused by genetic factors, environmental influences, systemic diseases, or localized dental conditions during tooth formation.

Some examples of tooth abnormalities include:

1. Microdontia - teeth that are smaller than normal in size.
2. Macrodontia - teeth that are larger than normal in size.
3. Peg-shaped teeth - teeth with a narrow, conical shape.
4. Talon cusps - additional cusps or points on the biting surface of a tooth.
5. Dens invaginatus - an abnormal development where the tooth crown has an extra fold or pouch that can trap bacteria and cause dental problems.
6. Taurodontism - teeth with large pulp chambers and short roots.
7. Supernumerary teeth - having more teeth than the typical number (20 primary and 32 permanent teeth).
8. Hypodontia - missing one or more teeth due to a failure of development.
9. Germination - two adjacent teeth fused together, usually occurring in the front teeth.
10. Fusion - two separate teeth that have grown together during development.

Tooth abnormalities may not always require treatment unless they cause functional, aesthetic, or dental health issues. A dentist can diagnose and manage tooth abnormalities through various treatments, such as fillings, extractions, orthodontic care, or restorative procedures.

Ataxia telangiectasia is a rare, inherited genetic disorder that affects the nervous system, immune system, and overall development. The condition is characterized by progressive difficulty with coordination and balance (ataxia), as well as the development of small, dilated blood vessels (telangiectasias) on the skin and eyes.

The underlying cause of ataxia telangiectasia is a mutation in the ATM gene, which provides instructions for making a protein that plays a critical role in DNA repair and maintaining genetic stability. When this gene is mutated, cells are unable to properly repair damaged DNA, leading to an increased risk of cancer and other health problems.

Individuals with ataxia telangiectasia typically begin to show symptoms during early childhood, with progressive difficulties in coordination and balance, slurred speech, and recurrent respiratory infections due to weakened immune function. Over time, these symptoms can worsen, leading to significant disability and reduced life expectancy.

There is currently no cure for ataxia telangiectasia, and treatment is focused on managing the symptoms and complications of the condition. This may include physical therapy, speech therapy, and medications to help control infections and other health problems.

Physical chromosome mapping, also known as physical mapping or genomic mapping, is the process of determining the location and order of specific genes or DNA sequences along a chromosome based on their physical distance from one another. This is typically done by using various laboratory techniques such as restriction enzyme digestion, fluorescence in situ hybridization (FISH), and chromosome walking to identify the precise location of a particular gene or sequence on a chromosome.

Physical chromosome mapping provides important information about the organization and structure of chromosomes, and it is essential for understanding genetic diseases and disorders. By identifying the specific genes and DNA sequences that are associated with certain conditions, researchers can develop targeted therapies and treatments to improve patient outcomes. Additionally, physical chromosome mapping is an important tool for studying evolution and comparative genomics, as it allows scientists to compare the genetic makeup of different species and identify similarities and differences between them.

In genetics, sequence alignment is the process of arranging two or more DNA, RNA, or protein sequences to identify regions of similarity or homology between them. This is often done using computational methods to compare the nucleotide or amino acid sequences and identify matching patterns, which can provide insight into evolutionary relationships, functional domains, or potential genetic disorders. The alignment process typically involves adjusting gaps and mismatches in the sequences to maximize the similarity between them, resulting in an aligned sequence that can be visually represented and analyzed.

A gene suppressor, also known as a tumor suppressor gene, is a type of gene that regulates cell growth and division by producing proteins to prevent uncontrolled cell proliferation. When these genes are mutated or deleted, they can lose their ability to regulate cell growth, leading to the development of cancer.

Tumor suppressor genes work to repair damaged DNA, regulate the cell cycle, and promote programmed cell death (apoptosis) when necessary. Some examples of tumor suppressor genes include TP53, BRCA1, and BRCA2. Mutations in these genes have been linked to an increased risk of developing various types of cancer, such as breast, ovarian, and colon cancer.

In contrast to oncogenes, which promote cell growth and division when mutated, tumor suppressor genes typically act to inhibit or slow down cell growth and division. Both types of genes play crucial roles in maintaining the proper functioning of cells and preventing the development of cancer.

Usher Syndromes are a group of genetic disorders that are characterized by hearing loss and visual impairment due to retinitis pigmentosa. They are the most common cause of deafblindness in developed countries. There are three types of Usher Syndromes (Type 1, Type 2, and Type 3) which differ in the age of onset, severity, and progression of hearing loss and vision loss.

Type 1 Usher Syndrome is the most severe form, with profound deafness present at birth or within the first year of life, and retinitis pigmentosa leading to significant vision loss by the teenage years. Type 2 Usher Syndrome is characterized by moderate to severe hearing loss beginning in childhood and vision loss due to retinitis pigmentosa starting in adolescence or early adulthood. Type 3 Usher Syndrome has progressive hearing loss that begins in adolescence and vision loss due to retinitis pigmentosa starting in the third decade of life.

The diagnosis of Usher Syndromes is based on a combination of clinical examination, audiological evaluation, and genetic testing. There is currently no cure for Usher Syndromes, but various assistive devices and therapies can help manage the symptoms and improve quality of life.

A chronic granulomatous disease (CGD) is a group of rare inherited disorders that affect the body's ability to fight off certain types of bacterial and fungal infections. It is characterized by the formation of granulomas, which are abnormal masses or nodules composed of immune cells called macrophages that cluster together in an attempt to wall off and destroy the infectious agents.

In CGD, the macrophages have a genetic defect that prevents them from producing reactive oxygen species (ROS), which are molecules that help kill bacteria and fungi. As a result, the immune system is unable to effectively eliminate these pathogens, leading to chronic inflammation and the formation of granulomas.

CGD is typically diagnosed in childhood and can affect various organs and systems in the body, including the lungs, gastrointestinal tract, skin, and lymph nodes. Symptoms may include recurrent infections, fever, fatigue, weight loss, cough, diarrhea, and abdominal pain. Treatment typically involves antibiotics or antifungal medications to manage infections, as well as immunosuppressive therapy to control inflammation and prevent the formation of granulomas. In some cases, bone marrow transplantation may be considered as a curative treatment option.

Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.

Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.

In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.

Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).

Genetic variation refers to the differences in DNA sequences among individuals and populations. These variations can result from mutations, genetic recombination, or gene flow between populations. Genetic variation is essential for evolution by providing the raw material upon which natural selection acts. It can occur within a single gene, between different genes, or at larger scales, such as differences in the number of chromosomes or entire sets of chromosomes. The study of genetic variation is crucial in understanding the genetic basis of diseases and traits, as well as the evolutionary history and relationships among species.

A gene is a specific sequence of nucleotides in DNA that carries genetic information. Genes are the fundamental units of heredity and are responsible for the development and function of all living organisms. They code for proteins or RNA molecules, which carry out various functions within cells and are essential for the structure, function, and regulation of the body's tissues and organs.

Each gene has a specific location on a chromosome, and each person inherits two copies of every gene, one from each parent. Variations in the sequence of nucleotides in a gene can lead to differences in traits between individuals, including physical characteristics, susceptibility to disease, and responses to environmental factors.

Medical genetics is the study of genes and their role in health and disease. It involves understanding how genes contribute to the development and progression of various medical conditions, as well as identifying genetic risk factors and developing strategies for prevention, diagnosis, and treatment.

A nuclear family, in medical and social sciences, refers to a family structure consisting of two married parents and their biological or adopted children living together in one household. It's the basic unit of a traditional family structure, typically comprising of a father (male parent), a mother (female parent) and their direct offspring. However, it's important to note that there are many different types of families and none is considered universally superior or normative. The concept of a nuclear family has evolved over time and varies across cultures and societies.

"Saccharomyces cerevisiae" is not typically considered a medical term, but it is a scientific name used in the field of microbiology. It refers to a species of yeast that is commonly used in various industrial processes, such as baking and brewing. It's also widely used in scientific research due to its genetic tractability and eukaryotic cellular organization.

However, it does have some relevance to medical fields like medicine and nutrition. For example, certain strains of S. cerevisiae are used as probiotics, which can provide health benefits when consumed. They may help support gut health, enhance the immune system, and even assist in the digestion of certain nutrients.

In summary, "Saccharomyces cerevisiae" is a species of yeast with various industrial and potential medical applications.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Ectromelia is a medical term that refers to the congenital absence or malformation of a limb or extremity. It is also known as "congenital amputation" or "limb reduction defect." This condition can affect any extremity, including arms, legs, hands, or feet, and can range from mild, such as a missing finger or toe, to severe, such as the absence of an entire limb.

Ectromelia can be caused by various factors, including genetic mutations, environmental factors, or a combination of both. In some cases, the cause may be unknown. Treatment options for ectromelia depend on the severity and location of the malformation and may include prosthetics, physical therapy, or surgery.

I'm sorry for any confusion, but "siblings" is not a medical term. It is a term used in genealogy and sociology to refer to the brothers and sisters that someone has. Sibling relationships can have medical implications, such as when inherited genetic disorders are present in a family, but the term "siblings" itself does not have a specific medical definition.

Diploidy is a term used in genetics to describe the state of having two sets of chromosomes in each cell. In diploid organisms, one set of chromosomes is inherited from each parent, resulting in a total of 2 sets of chromosomes.

In humans, for example, most cells are diploid and contain 46 chromosomes arranged in 23 pairs. This includes 22 pairs of autosomal chromosomes and one pair of sex chromosomes (XX in females or XY in males). Diploidy is a characteristic feature of many complex organisms, including animals, plants, and fungi.

Diploid cells can undergo a process called meiosis, which results in the formation of haploid cells that contain only one set of chromosomes. These haploid cells can then combine with other haploid cells during fertilization to form a new diploid organism.

Abnormalities in diploidy can lead to genetic disorders, such as Down syndrome, which occurs when an individual has three copies of chromosome 21 instead of the typical two. This extra copy of the chromosome can result in developmental delays and intellectual disabilities.

A case-control study is an observational research design used to identify risk factors or causes of a disease or health outcome. In this type of study, individuals with the disease or condition (cases) are compared with similar individuals who do not have the disease or condition (controls). The exposure history or other characteristics of interest are then compared between the two groups to determine if there is an association between the exposure and the disease.

Case-control studies are often used when it is not feasible or ethical to conduct a randomized controlled trial, as they can provide valuable insights into potential causes of diseases or health outcomes in a relatively short period of time and at a lower cost than other study designs. However, because case-control studies rely on retrospective data collection, they are subject to biases such as recall bias and selection bias, which can affect the validity of the results. Therefore, it is important to carefully design and conduct case-control studies to minimize these potential sources of bias.

I'm sorry for any confusion, but "Syria" is not a medical term. It is a country located in the Middle East. If you are looking for information about a medical condition, could you please provide more details? I'd be happy to help with that.

Amelogenesis Imperfecta is a group of inherited dental disorders that affect the structure and appearance of tooth enamel. It is caused by mutations in various genes involved in the development and formation of enamel. The condition can be characterized by small, discolored, and poorly formed teeth that are prone to rapid wear, decay, and sensitivity. There are several types of Amelogenesis Imperfecta, which vary in their severity and the specific symptoms they present. Treatment typically focuses on managing the symptoms and improving the appearance and function of the teeth through restorative dental procedures.

Restriction Fragment Length Polymorphism (RFLP) is a term used in molecular biology and genetics. It refers to the presence of variations in DNA sequences among individuals, which can be detected by restriction enzymes. These enzymes cut DNA at specific sites, creating fragments of different lengths.

In RFLP analysis, DNA is isolated from an individual and treated with a specific restriction enzyme that cuts the DNA at particular recognition sites. The resulting fragments are then separated by size using gel electrophoresis, creating a pattern unique to that individual's DNA. If there are variations in the DNA sequence between individuals, the restriction enzyme may cut the DNA at different sites, leading to differences in the length of the fragments and thus, a different pattern on the gel.

These variations can be used for various purposes, such as identifying individuals, diagnosing genetic diseases, or studying evolutionary relationships between species. However, RFLP analysis has largely been replaced by more modern techniques like polymerase chain reaction (PCR)-based methods and DNA sequencing, which offer higher resolution and throughput.

A chromosome is a thread-like structure that contains genetic material, made up of DNA and proteins, in the nucleus of a cell. In humans, there are 23 pairs of chromosomes, for a total of 46 chromosomes, in each cell of the body, with the exception of the sperm and egg cells which contain only 23 chromosomes.

The X chromosome is one of the two sex-determining chromosomes in humans. Females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The X chromosome contains hundreds of genes that are responsible for various functions in the body, including some related to sexual development and reproduction.

Humans inherit one X chromosome from their mother and either an X or a Y chromosome from their father. In females, one of the two X chromosomes is randomly inactivated during embryonic development, resulting in each cell having only one active X chromosome. This process, known as X-inactivation, helps to ensure that females have roughly equal levels of gene expression from the X chromosome, despite having two copies.

Abnormalities in the number or structure of the X chromosome can lead to various genetic disorders, such as Turner syndrome (X0), Klinefelter syndrome (XXY), and fragile X syndrome (an X-linked disorder caused by a mutation in the FMR1 gene).

Human chromosome pair 5 consists of two rod-shaped structures present in the nucleus of human cells, which contain genetic material in the form of DNA and proteins. Each member of chromosome pair 5 is a single chromosome, and humans typically have 23 pairs of chromosomes for a total of 46 chromosomes in every cell of their body (except gametes or sex cells, which contain 23 chromosomes).

Chromosome pair 5 is one of the autosomal pairs, meaning it is not a sex chromosome. Each member of chromosome pair 5 is approximately 197 million base pairs in length and contains around 800-900 genes that provide instructions for making proteins and regulating various cellular processes.

Chromosome pair 5 is associated with several genetic disorders, including cri du chat syndrome (resulting from a deletion on the short arm of chromosome 5), Prader-Willi syndrome and Angelman syndrome (both resulting from abnormalities in gene expression on the long arm of chromosome 5).

Limb-girdle muscular dystrophy (LGMD) is a group of rare inherited disorders that cause progressive weakness and wasting of the muscles in the arms and legs, particularly those around the shoulders and hips (the limb-girdle region). The condition affects both males and females and presents at different ages, depending on the specific type of LGMD.

LGMD is caused by mutations in various genes that play a role in maintaining muscle integrity and function. These genetic defects lead to a deficiency or dysfunction of certain proteins necessary for muscle health, ultimately resulting in muscle degeneration and weakness. There are more than 30 different subtypes of LGMD, each with its own set of causative genes and inheritance patterns (autosomal dominant or autosomal recessive).

Symptoms of limb-girdle muscular dystrophy may include:

1. Progressive muscle weakness and wasting in the arms, legs, shoulders, and hips
2. Difficulty with activities such as climbing stairs, lifting objects, or getting up from a seated position
3. Enlarged calf muscles (pseudohypertrophy) due to muscle degeneration and fat replacement
4. Muscle contractures, joint stiffness, and limited range of motion
5. Difficulty walking, using wheelchair assistance in advanced stages
6. Respiratory complications due to weakened chest muscles in some cases

Diagnosis of LGMD typically involves a combination of clinical evaluation, family history, muscle biopsy, genetic testing, and blood tests for creatine kinase (CK) levels, which are often elevated in muscular dystrophies. Treatment is primarily supportive and focuses on maintaining mobility, preventing complications, and preserving quality of life through physical therapy, assistive devices, and orthopedic interventions as needed. No cure currently exists for limb-girdle muscular dystrophy, but ongoing research aims to develop targeted therapies based on the underlying genetic defects.

Spinocerebellar ataxias (SCAs) are a group of genetic disorders that affect the cerebellum, which is the part of the brain responsible for coordinating muscle movements. SCAs are characterized by progressive problems with balance, speech, and coordination. They are caused by mutations in various genes that result in the production of abnormal proteins that accumulate in neurons, leading to their degeneration.

There are over 40 different types of SCAs, each caused by a different genetic mutation. Some of the more common types include SCA1, SCA2, SCA3, SCA6, and SCA7. The symptoms and age of onset can vary widely depending on the type of SCA.

In addition to problems with coordination and balance, people with SCAs may also experience muscle weakness, stiffness, tremors, spasticity, and difficulty swallowing or speaking. Some types of SCAs can also cause visual disturbances, hearing loss, and cognitive impairment. Currently, there is no cure for SCAs, but treatments such as physical therapy, speech therapy, and medications can help manage the symptoms.

Prenatal diagnosis is the medical testing of fetuses, embryos, or pregnant women to detect the presence or absence of certain genetic disorders or birth defects. These tests can be performed through various methods such as chorionic villus sampling (CVS), amniocentesis, or ultrasound. The goal of prenatal diagnosis is to provide early information about the health of the fetus so that parents and healthcare providers can make informed decisions about pregnancy management and newborn care. It allows for early intervention, treatment, or planning for the child's needs after birth.

Agenesis of the corpus callosum is a birth defect in which the corpus callosum, the part of the brain that connects the two hemispheres and allows them to communicate, fails to develop normally during fetal development. In cases of agenesis of the corpus callosum, the corpus callosum is partially or completely absent.

This condition can vary in severity and may be associated with other brain abnormalities. Some individuals with agenesis of the corpus callosum may have normal intelligence and few symptoms, while others may have intellectual disability, developmental delays, seizures, vision problems, and difficulties with movement and coordination. The exact cause of agenesis of the corpus callosum is not always known, but it can be caused by genetic factors or exposure to certain medications or environmental toxins during pregnancy.

Retinal dystrophies are a group of genetic eye disorders that primarily affect the retina, a light-sensitive layer at the back of the eye. These conditions are characterized by progressive degeneration and death of photoreceptor cells (rods and cones) in the retina, leading to vision loss.

The term "dystrophy" refers to a condition that results from the abnormal or defective development and function of tissues or organs. In the case of retinal dystrophies, the photoreceptor cells do not develop or function properly, resulting in visual impairment.

Retinal dystrophies can present at any age, from infancy to adulthood, and can have varying degrees of severity. Some common symptoms include night blindness, decreased visual acuity, loss of peripheral vision, light sensitivity, and color vision abnormalities.

Examples of retinal dystrophies include retinitis pigmentosa, Stargardt disease, Usher syndrome, and Leber congenital amaurosis, among others. These conditions are typically inherited and can be caused by mutations in various genes that play a role in the development and function of the retina.

There is currently no cure for retinal dystrophies, but research is ongoing to develop treatments that may slow or halt the progression of these conditions, such as gene therapy and stem cell transplantation.

Pseudoxanthoma Elasticum (PXE) is a rare genetic disorder characterized by the calcification and fragmentation of elastic fibers in the skin, eyes, and cardiovascular system. This causes changes in these tissues, leading to the clinical features of the disease. In the skin, this manifests as yellowish papules and plaques, often located on the neck, axillae, and flexural areas. In the eyes, it can cause angioid streaks, peau d'orange, and choroidal neovascularization, potentially leading to visual loss. In the cardiovascular system, calcification of the elastic fibers in the arterial walls can lead to premature atherosclerosis and increased risk of cardiovascular events. The disease is caused by mutations in the ABCC6 gene.

Polydactyly is a genetic condition where an individual is born with more than the usual number of fingers or toes, often caused by mutations in specific genes. It can occur as an isolated trait or as part of a genetic syndrome. The additional digit(s) may be fully formed and functional, underdeveloped, or just a small bump. Polydactyly is one of the most common congenital limb abnormalities.

"Fundus Oculi" is a medical term that refers to the back part of the interior of the eye, including the optic disc, macula, fovea, retinal vasculature, and peripheral retina. It is the area where light is focused and then transmitted to the brain via the optic nerve, forming visual images. Examinations of the fundus oculi are crucial for detecting various eye conditions such as diabetic retinopathy, macular degeneration, glaucoma, and other retinal diseases. The examination is typically performed using an ophthalmoscope or a specialized camera called a retinal camera.

Connexins are a family of proteins that form the structural units of gap junctions, which are specialized channels that allow for the direct exchange of small molecules and ions between adjacent cells. These channels play crucial roles in maintaining tissue homeostasis, coordinating cellular activities, and enabling communication between cells. In humans, there are 21 different connexin genes that encode for these proteins, with each isoform having unique properties and distributions within the body. Mutations in connexin genes have been linked to a variety of human diseases, including hearing loss, skin disorders, and heart conditions.

A genetic locus (plural: loci) is a specific location on a chromosome where a particular gene or DNA sequence is found. It is the precise position where a specific genetic element, such as a gene or marker, is located on a chromsomere. This location is defined in terms of its relationship to other genetic markers and features on the same chromosome. Genetic loci can be used in linkage and association studies to identify the inheritance patterns and potential relationships between genes and various traits or diseases.

Familial Mediterranean Fever (FMF) is a hereditary inflammatory disorder that primarily affects people of Mediterranean ancestry, including populations from Turkey, Armenia, Arab countries, and Jewish communities from the Middle East. It is caused by mutations in the MEFV gene, which provides instructions for making a protein called pyrin or marenostrin.

The main features of FMF include recurrent episodes of fever, serositis (inflammation of the membranes lining the abdominal cavity, chest cavity, or heart), and polyserositis (inflammation affecting multiple serous membranes simultaneously). The attacks usually last between 12 and 72 hours and can be associated with severe abdominal pain, joint pain, and skin rashes.

The diagnosis of FMF is based on clinical criteria, family history, and genetic testing. Treatment typically involves the use of colchicine, an anti-inflammatory medication that helps prevent attacks and reduces the risk of long-term complications such as amyloidosis, a condition characterized by the buildup of abnormal protein deposits in various organs.

Early diagnosis and treatment of FMF are essential to prevent complications and improve quality of life for affected individuals.

Cyclic nucleotide phosphodiesterases (PDEs) are a family of enzymes that play a crucial role in regulating intracellular levels of cyclic nucleotides, which are important second messengers in various cellular signaling pathways. Among the different types of PDEs, type 6 (PDE6) is specifically expressed in the photoreceptor cells of the retina and is involved in the visual signal transduction cascade.

PDE6 is composed of two catalytic subunits, PDE6α and PDE6β, which are arranged in a heterodimeric complex. These subunits have distinct roles in the enzyme's activity: PDE6α contains the catalytic site that hydrolyzes cyclic guanosine monophosphate (cGMP) to GMP, while PDE6β regulates the activity of PDE6α through its inhibitory γ subunit.

In the visual signal transduction pathway, light stimulation leads to the activation of rhodopsin, which triggers a cascade of events that ultimately results in the hydrolysis of cGMP by PDE6. This reduction in cGMP levels causes the closure of cyclic nucleotide-gated channels in the plasma membrane, leading to hyperpolarization of the photoreceptor cells and the transmission of visual signals to the brain.

Defects in PDE6 have been implicated in various retinal disorders, including congenital stationary night blindness, retinitis pigmentosa, and age-related macular degeneration. Therefore, understanding the structure and function of PDE6 is essential for developing novel therapeutic strategies to treat these vision-threatening diseases.

Blindness is a condition of complete or near-complete vision loss. It can be caused by various factors such as eye diseases, injuries, or birth defects. Total blindness means that a person cannot see anything at all, while near-complete blindness refers to having only light perception or the ability to perceive the direction of light, but not able to discern shapes or forms. Legal blindness is a term used to define a certain level of visual impairment that qualifies an individual for government assistance and benefits; it usually means best corrected visual acuity of 20/200 or worse in the better eye, or a visual field no greater than 20 degrees in diameter.

Human chromosome pair 7 consists of two rod-shaped structures present in the nucleus of each cell in the human body. Each member of the pair is a single chromosome, and together they contain the genetic material that is inherited from both parents. They are identical in size, shape, and banding pattern and are therefore referred to as homologous chromosomes.

Chromosome 7 is one of the autosomal chromosomes, meaning it is not a sex chromosome (X or Y). It is composed of double-stranded DNA that contains approximately 159 million base pairs and around 1,200 genes. Chromosome 7 contains several important genes associated with human health and disease, including those involved in the development of certain types of cancer, such as colon cancer and lung cancer, as well as genetic disorders such as Williams-Beuren syndrome and Charcot-Marie-Tooth disease.

Abnormalities in chromosome 7 have been linked to various genetic conditions, including deletions, duplications, translocations, and other structural changes. These abnormalities can lead to developmental delays, intellectual disabilities, physical abnormalities, and increased risk of certain types of cancer.

Genetic recombination is the process by which genetic material is exchanged between two similar or identical molecules of DNA during meiosis, resulting in new combinations of genes on each chromosome. This exchange occurs during crossover, where segments of DNA are swapped between non-sister homologous chromatids, creating genetic diversity among the offspring. It is a crucial mechanism for generating genetic variability and facilitating evolutionary change within populations. Additionally, recombination also plays an essential role in DNA repair processes through mechanisms such as homologous recombinational repair (HRR) and non-homologous end joining (NHEJ).

Human chromosome pair 3 consists of two rod-shaped structures present in the nucleus of each cell in the human body. Each member of the pair is a single chromosome, and together they contain the genetic material that is inherited from both parents. Chromosomes are made up of DNA, which contains the instructions for the development and function of all living organisms.

Human chromosomes are numbered from 1 to 22, with an additional two sex chromosomes (X and Y) that determine biological sex. Chromosome pair 3 is one of the autosomal pairs, meaning it contains genes that are not related to sex determination. Each member of chromosome pair 3 is identical in size and shape and contains a single long DNA molecule that is coiled tightly around histone proteins to form a compact structure.

Chromosome pair 3 is associated with several genetic disorders, including Waardenburg syndrome, which affects pigmentation and hearing; Marfan syndrome, which affects the connective tissue; and some forms of retinoblastoma, a rare eye cancer that typically affects young children.

A codon is a sequence of three adjacent nucleotides in DNA or RNA that specifies a particular amino acid during the process of protein synthesis, or codes for the termination of translation. In DNA, these triplets are read in a 5' to 3' direction, while in mRNA, they are read in a 5' to 3' direction as well. There are 64 possible codons (4^3) in the genetic code, and 61 of them specify amino acids. The remaining three codons, UAA, UAG, and UGA, are terminator or stop codons that signal the end of protein synthesis.

Terminator codons, also known as nonsense codons, do not code for any amino acids. Instead, they cause the release of the newly synthesized polypeptide chain from the ribosome, which is the complex machinery responsible for translating the genetic code into a protein. This process is called termination or translation termination.

In prokaryotic cells, termination occurs when a release factor recognizes and binds to the stop codon in the A site of the ribosome. This triggers the hydrolysis of the peptidyl-tRNA bond, releasing the completed polypeptide chain from the tRNA and the ribosome. In eukaryotic cells, a similar process occurs, but it involves different release factors and additional steps to ensure accurate termination.

In summary, a codon is a sequence of three adjacent nucleotides in DNA or RNA that specifies an amino acid or signals the end of protein synthesis. Terminator codons are specific codons that do not code for any amino acids and instead signal the end of translation, leading to the release of the newly synthesized polypeptide chain from the ribosome.

Leber Congenital Amaurosis (LCA) is a group of inherited retinal degenerative disorders that affect the development and function of the retina, a light-sensitive tissue at the back of the eye. It is characterized by severe visual impairment or blindness from birth or early infancy.

The condition is caused by mutations in various genes involved in the normal functioning of photoreceptor cells (rods and cones) in the retina, which are responsible for capturing light and transmitting visual signals to the brain. As a result, the photoreceptors fail to develop properly or degenerate over time, leading to vision loss.

Symptoms of LCA may include roving eye movements (nystagmus), lack of fixation, decreased or absent response to light, and abnormal pupillary reflexes. Some individuals with LCA may also have other ocular abnormalities such as keratoconus, cataracts, or glaucoma.

LCA is typically inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to develop the condition. Currently, there is no cure for LCA, but various treatments such as gene therapy and assistive devices may help improve visual function and quality of life for affected individuals.

I'm sorry for any confusion, but "Israel" is not a medical term. It is a country located in the Middle East. If you have any medical questions or terms you would like defined, I would be happy to help!

Fungal genes refer to the genetic material present in fungi, which are eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. The genetic material of fungi is composed of DNA, just like in other eukaryotes, and is organized into chromosomes located in the nucleus of the cell.

Fungal genes are segments of DNA that contain the information necessary to produce proteins and RNA molecules required for various cellular functions. These genes are transcribed into messenger RNA (mRNA) molecules, which are then translated into proteins by ribosomes in the cytoplasm.

Fungal genomes have been sequenced for many species, revealing a diverse range of genes that encode proteins involved in various cellular processes such as metabolism, signaling, and regulation. Comparative genomic analyses have also provided insights into the evolutionary relationships among different fungal lineages and have helped to identify unique genetic features that distinguish fungi from other eukaryotes.

Understanding fungal genes and their functions is essential for advancing our knowledge of fungal biology, as well as for developing new strategies to control fungal pathogens that can cause diseases in humans, animals, and plants.

Lipoid proteinosis of Urbach and Wiethe is a rare genetic disorder characterized by the accumulation of abnormal protein and lipid (fat) deposits in various tissues throughout the body, particularly in the skin, mucous membranes, and central nervous system. The condition is caused by mutations in the ECM1 gene, which provides instructions for making a protein that is essential for the normal development and maintenance of several types of tissue.

The signs and symptoms of lipoid proteinosis can vary widely among affected individuals, but they typically include:

* Hoarseness or husky voice due to deposition of material in the vocal cords
* Skin abnormalities such as thickened skin, yellowish bumps (xanthomas), and scarring from minor injuries
* Eye problems such as corneal opacities, dry eyes, and increased sensitivity to light
* Central nervous system involvement, including seizures, behavioral abnormalities, and intellectual disability

The accumulation of abnormal protein and lipid deposits in the brain can also lead to an increased risk of developing amyloidosis, a condition in which abnormal proteins called amyloids build up in various organs and interfere with their normal function.

There is no cure for lipoid proteinosis, but treatment is focused on managing the symptoms and complications of the disease. This may include speech therapy for hoarseness, skin care to prevent scarring, and medications to control seizures or other neurological symptoms.

Human chromosome pair 11 consists of two rod-shaped structures present in the nucleus of each cell in the human body. Each member of the pair is a single chromosome, and together they contain the genetic material that is inherited from both parents. They are located on the eleventh position in the standard karyotype, which is a visual representation of the 23 pairs of human chromosomes.

Chromosome 11 is one of the largest human chromosomes and contains an estimated 135 million base pairs. It contains approximately 1,400 genes that provide instructions for making proteins, as well as many non-coding RNA molecules that play a role in regulating gene expression.

Chromosome 11 is known to contain several important genes and genetic regions associated with various human diseases and conditions. For example, it contains the Wilms' tumor 1 (WT1) gene, which is associated with kidney cancer in children, and the neurofibromatosis type 1 (NF1) gene, which is associated with a genetic disorder that causes benign tumors to grow on nerves throughout the body. Additionally, chromosome 11 contains the region where the ABO blood group genes are located, which determine a person's blood type.

It's worth noting that human chromosomes come in pairs because they contain two copies of each gene, one inherited from the mother and one from the father. This redundancy allows for genetic diversity and provides a backup copy of essential genes, ensuring their proper function and maintaining the stability of the genome.

Methemoglobinemia is a medical condition characterized by an increased level of methemoglobin in the blood. Methemoglobin is a form of hemoglobin that cannot effectively transport oxygen throughout the body due to the iron atom within its structure being oxidized from the ferrous (Fe2+) state to the ferric (Fe3+) state.

Under normal circumstances, methemoglobin levels are kept below 1% of total hemoglobin. However, when these levels rise above 10%, it can lead to symptoms such as shortness of breath, headache, fatigue, and cyanosis (a bluish discoloration of the skin and mucous membranes). Severe methemoglobinemia, with levels exceeding 50%, can result in life-threatening complications, including seizures, coma, and even death.

Methemoglobinemia can be congenital or acquired. Congenital methemoglobinemia is caused by genetic defects affecting the enzymes responsible for reducing methemoglobin back to its functional form, hemoglobin. Acquired methemoglobinemia can result from exposure to certain medications, chemicals, or toxins that oxidize hemoglobin and increase methemoglobin levels. Treatment typically involves administering methylene blue, a reducing agent that helps convert methemoglobin back to functional hemoglobin. In severe cases or when methylene blue is contraindicated, alternative treatments such as exchange transfusions or hyperbaric oxygen therapy may be considered.

I'm sorry for any confusion, but "hybrid cells" is not a standard medical term with a widely accepted or specific definition in the field of medicine. The term "hybrid" is used in various scientific and medical contexts to describe combinations or mixtures of different elements, such as hybridoma cells (a type of fusion cell used in research, created by combining a B cell and a tumor cell) or hybridization (in genetics, the process of combining DNA from two different sources).

Without more specific context, it's difficult to provide an accurate medical definition for "hybrid cells." If you could provide more information about the context in which this term was used, I would be happy to help you further!

Immunologic deficiency syndromes refer to a group of disorders characterized by defective functioning of the immune system, leading to increased susceptibility to infections and malignancies. These deficiencies can be primary (genetic or congenital) or secondary (acquired due to environmental factors, medications, or diseases).

Primary immunodeficiency syndromes (PIDS) are caused by inherited genetic mutations that affect the development and function of immune cells, such as T cells, B cells, and phagocytes. Examples include severe combined immunodeficiency (SCID), common variable immunodeficiency (CVID), Wiskott-Aldrich syndrome, and X-linked agammaglobulinemia.

Secondary immunodeficiency syndromes can result from various factors, including:

1. HIV/AIDS: Human Immunodeficiency Virus infection leads to the depletion of CD4+ T cells, causing profound immune dysfunction and increased vulnerability to opportunistic infections and malignancies.
2. Medications: Certain medications, such as chemotherapy, immunosuppressive drugs, and long-term corticosteroid use, can impair immune function and increase infection risk.
3. Malnutrition: Deficiencies in essential nutrients like protein, vitamins, and minerals can weaken the immune system and make individuals more susceptible to infections.
4. Aging: The immune system naturally declines with age, leading to an increased incidence of infections and poorer vaccine responses in older adults.
5. Other medical conditions: Chronic diseases such as diabetes, cancer, and chronic kidney or liver disease can also compromise the immune system and contribute to immunodeficiency syndromes.

Immunologic deficiency syndromes require appropriate diagnosis and management strategies, which may include antimicrobial therapy, immunoglobulin replacement, hematopoietic stem cell transplantation, or targeted treatments for the underlying cause.

Nerve tissue proteins are specialized proteins found in the nervous system that provide structural and functional support to nerve cells, also known as neurons. These proteins include:

1. Neurofilaments: These are type IV intermediate filaments that provide structural support to neurons and help maintain their shape and size. They are composed of three subunits - NFL (light), NFM (medium), and NFH (heavy).

2. Neuronal Cytoskeletal Proteins: These include tubulins, actins, and spectrins that provide structural support to the neuronal cytoskeleton and help maintain its integrity.

3. Neurotransmitter Receptors: These are specialized proteins located on the postsynaptic membrane of neurons that bind neurotransmitters released by presynaptic neurons, triggering a response in the target cell.

4. Ion Channels: These are transmembrane proteins that regulate the flow of ions across the neuronal membrane and play a crucial role in generating and transmitting electrical signals in neurons.

5. Signaling Proteins: These include enzymes, receptors, and adaptor proteins that mediate intracellular signaling pathways involved in neuronal development, differentiation, survival, and death.

6. Adhesion Proteins: These are cell surface proteins that mediate cell-cell and cell-matrix interactions, playing a crucial role in the formation and maintenance of neural circuits.

7. Extracellular Matrix Proteins: These include proteoglycans, laminins, and collagens that provide structural support to nerve tissue and regulate neuronal migration, differentiation, and survival.

RecQ helicases are a group of enzymes that belong to the RecQ family, which are named after the E. coli RecQ protein. These helicases play crucial roles in maintaining genomic stability by participating in various DNA metabolic processes such as DNA replication, repair, recombination, and transcription. They are highly conserved across different species, including bacteria, yeast, plants, and mammals.

In humans, there are five RecQ helicases: RECQL1, RECQL4, RECQL5, BLM (RecQ-like helicase), and WRN (Werner syndrome ATP-dependent helicase). Defects in these proteins have been linked to various genetic disorders. For instance, mutations in the BLM gene cause Bloom's syndrome, while mutations in the WRN gene lead to Werner syndrome, both of which are characterized by genomic instability and increased cancer predisposition.

RecQ helicases possess 3'-5' DNA helicase activity, unwinding double-stranded DNA into single strands, and can also perform other functions like branch migration, strand annealing, and removal of protein-DNA crosslinks. Their roles in DNA metabolism help prevent and resolve DNA damage, maintain proper chromosome segregation during cell division, and ensure the integrity of the genome.

Albinism is a group of genetic disorders that result in little or no production of melanin, the pigment responsible for coloring skin, hair, and eyes. It is caused by mutations in genes involved in the production of melanin. There are several types of albinism, including oculocutaneous albinism (OCA) and ocular albinism (OA). OCA affects the skin, hair, and eyes, while OA primarily affects the eyes.

People with albinism typically have very pale skin, white or light-colored hair, and light-colored eyes. They may also have vision problems, such as sensitivity to light (photophobia), rapid eye movements (nystagmus), and decreased visual acuity. The severity of these symptoms can vary depending on the type and extent of albinism.

Albinism is inherited in an autosomal recessive manner, which means that an individual must inherit two copies of the mutated gene, one from each parent, in order to have the condition. If both parents are carriers of a mutated gene for albinism, they have a 25% chance with each pregnancy of having a child with albinism.

There is no cure for albinism, but individuals with the condition can take steps to protect their skin and eyes from the sun and use visual aids to help with vision problems. It is important for people with albinism to undergo regular eye examinations and to use sun protection, such as sunscreen, hats, and sunglasses, to prevent skin damage and skin cancer.

Epistasis is a phenomenon in genetics where the effect of one gene (the "epistatic" gene) is modified by one or more other genes (the "modifier" genes). This interaction can result in different phenotypic expressions than what would be expected based on the individual effects of each gene.

In other words, epistasis occurs when the expression of one gene is influenced by the presence or absence of another gene. The gene that is being masked or modified is referred to as the hypostatic gene, while the gene doing the masking or modifying is called the epistatic gene.

Epistasis can take many forms and can be involved in complex genetic traits and diseases. It can also make it more difficult to map genes associated with certain traits or conditions because the phenotypic expression may not follow simple Mendelian inheritance patterns.

There are several types of epistasis, including recessive-recessive, dominant-recessive, and dominant-dominant epistasis. In recessive-recessive epistasis, for example, the presence of two copies of the epistatic gene prevents the expression of the hypostatic gene, even if the individual has two copies of the hypostatic gene.

Understanding epistasis is important in genetics because it can help researchers better understand the genetic basis of complex traits and diseases, as well as improve breeding programs for plants and animals.

Spinocerebellar degenerations (SCDs) are a group of genetic disorders that primarily affect the cerebellum, the part of the brain responsible for coordinating muscle movements, and the spinal cord. These conditions are characterized by progressive degeneration or loss of nerve cells in the cerebellum and/or spinal cord, leading to various neurological symptoms.

SCDs are often inherited in an autosomal dominant manner, meaning that only one copy of the altered gene from either parent is enough to cause the disorder. The most common type of SCD is spinocerebellar ataxia (SCA), which includes several subtypes (SCA1, SCA2, SCA3, etc.) differentiated by their genetic causes and specific clinical features.

Symptoms of spinocerebellar degenerations may include:

1. Progressive ataxia (loss of coordination and balance)
2. Dysarthria (speech difficulty)
3. Nystagmus (involuntary eye movements)
4. Oculomotor abnormalities (problems with eye movement control)
5. Tremors or other involuntary muscle movements
6. Muscle weakness and spasticity
7. Sensory disturbances, such as numbness or tingling sensations
8. Dysphagia (difficulty swallowing)
9. Cognitive impairment in some cases

The age of onset, severity, and progression of symptoms can vary significantly among different SCD subtypes and individuals. Currently, there is no cure for spinocerebellar degenerations, but various supportive treatments and therapies can help manage symptoms and improve quality of life.

I'm sorry for any confusion, but "Morocco" is not a medical term. It is the constitutional monarchy with a parliamentary national unity government located in North Africa. It has a population of over 33 million and an area of 446,550 km2. The capital city is Rabat, and the largest city is Casablanca. Morocco's official languages are Arabic and Berber, with French widely spoken as well.

If you have any medical questions or terms that you would like me to define, please let me know!

Cystinuria is a genetic disorder that affects the way the body handles certain amino acids, specifically cystine, arginine, lysine, and ornithine. These amino acids are normally reabsorbed in the kidneys and released into the bloodstream. However, people with cystinuria have a defect in the transport mechanism that causes large amounts of cystine to be excreted in the urine, where it can form stones in the urinary tract. These stones can cause pain, blockages, and infection. Cystinuria is inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the defective gene, one from each parent, to have the condition.

Iron-binding proteins, also known as transferrins, are a type of protein responsible for the transport and storage of iron in the body. They play a crucial role in maintaining iron homeostasis by binding free iron ions and preventing them from participating in harmful chemical reactions that can produce reactive oxygen species (ROS) and cause cellular damage.

Transferrin is the primary iron-binding protein found in blood plasma, while lactoferrin is found in various exocrine secretions such as milk, tears, and saliva. Both transferrin and lactoferrin have a similar structure, consisting of two lobes that can bind one ferric ion (Fe3+) each. When iron is bound to these proteins, they are called holo-transferrin or holo-lactoferrin; when they are unbound, they are referred to as apo-transferrin or apo-lactoferrin.

Iron-binding proteins have a high affinity for iron and can regulate the amount of free iron available in the body. They help prevent iron overload, which can lead to oxidative stress and cellular damage, as well as iron deficiency, which can result in anemia and other health problems.

In summary, iron-binding proteins are essential for maintaining iron homeostasis by transporting and storing iron ions, preventing them from causing harm to the body's cells.

Human chromosome pair 9 consists of two rod-shaped structures present in the nucleus of each cell of the human body. Each member of the pair contains thousands of genes and other genetic material, encoded in the form of DNA molecules. The two chromosomes in a pair are identical or very similar to each other in terms of their size, shape, and genetic makeup.

Chromosome 9 is one of the autosomal chromosomes, meaning that it is not a sex chromosome (X or Y) and is present in two copies in all cells of the body, regardless of sex. Chromosome 9 is a medium-sized chromosome, and it is estimated to contain around 135 million base pairs of DNA and approximately 1200 genes.

Chromosome 9 contains several important genes that are associated with various human traits and diseases. For example, mutations in the gene that encodes the protein APOE on chromosome 9 have been linked to an increased risk of developing Alzheimer's disease. Additionally, variations in the gene that encodes the protein EGFR on chromosome 9 have been associated with an increased risk of developing certain types of cancer.

Overall, human chromosome pair 9 plays a critical role in the development and function of the human body, and variations in its genetic makeup can contribute to a wide range of traits and diseases.

Corneal dystrophies, hereditary are a group of genetic disorders that affect the cornea, which is the clear, outermost layer at the front of the eye. These conditions are characterized by the buildup of abnormal material in the cornea, leading to decreased vision, pain, or cloudiness in the eye.

There are many different types of corneal dystrophies, each affecting a specific layer of the cornea and having its own pattern of inheritance. Some common types include:

1. Fuchs' endothelial dystrophy: This affects the inner lining of the cornea (endothelium) and causes swelling and cloudiness in the cornea. It is typically inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the condition if one parent has it.
2. Granular dystrophy: This affects the stroma, which is the middle layer of the cornea. It causes the formation of opaque, grayish-white deposits in the cornea that can affect vision. It is typically inherited in an autosomal dominant or recessive manner.
3. Lattice dystrophy: This also affects the stroma and is characterized by the formation of a lattice-like pattern of fine, whitish lines in the cornea. It is typically inherited in an autosomal dominant manner.
4. Macular dystrophy: This affects the central part of the cornea (macula) and can cause cloudiness, leading to decreased vision. It is typically inherited in an autosomal recessive manner.

Treatment for corneal dystrophies may include eyedrops, medications, or surgery, depending on the severity of the condition and its impact on vision. In some cases, a corneal transplant may be necessary to restore vision.

Chromosome aberrations refer to structural and numerical changes in the chromosomes that can occur spontaneously or as a result of exposure to mutagenic agents. These changes can affect the genetic material encoded in the chromosomes, leading to various consequences such as developmental abnormalities, cancer, or infertility.

Structural aberrations include deletions, duplications, inversions, translocations, and rings, which result from breaks and rearrangements of chromosome segments. Numerical aberrations involve changes in the number of chromosomes, such as aneuploidy (extra or missing chromosomes) or polyploidy (multiples of a complete set of chromosomes).

Chromosome aberrations can be detected and analyzed using various cytogenetic techniques, including karyotyping, fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH). These methods allow for the identification and characterization of chromosomal changes at the molecular level, providing valuable information for genetic counseling, diagnosis, and research.

Bloom syndrome is a rare genetic disorder characterized by short stature, sun-sensitive skin rash, and an increased risk of developing cancer. It is caused by mutations in the BLM gene, which provides instructions for making a protein that helps prevent tangles and knots from forming in DNA during cell division. As a result, cells with Bloom syndrome have a high rate of genetic recombination, leading to chromosomal instability and an increased risk of cancer.

Individuals with Bloom syndrome typically have a distinctive facial appearance, including a narrow face, small jaw, and a prominent nose. They may also have learning disabilities, fertility problems, and an increased susceptibility to infections. The condition is inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to develop the disorder. Bloom syndrome is typically diagnosed through genetic testing and chromosome analysis. Treatment is focused on managing the symptoms and reducing the risk of cancer through regular screenings and lifestyle modifications.

Ellis-van Creveld syndrome is a rare genetic disorder that affects the development of bones and other organs. It is characterized by short limbs, narrow chest, extra fingers or toes (polydactyly), heart defects, and abnormalities of the teeth and nails. The condition is caused by mutations in the EVC or EVC2 gene and is inherited in an autosomal recessive manner. It is also known as chondroectodermal dysplasia.

Caroli disease is a rare genetic disorder that affects the liver and bile ducts. It is characterized by abnormal dilations or sac-like structures in the intrahepatic bile ducts, which are the ducts that carry bile from the liver to the gallbladder and small intestine. These dilations can lead to recurrent cholangitis (inflammation of the bile ducts), stone formation, and liver damage.

Caroli disease is usually diagnosed in childhood or early adulthood, and it can be associated with other congenital anomalies such as polycystic kidney disease. The exact cause of Caroli disease is not fully understood, but it is believed to be inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the abnormal gene, one from each parent, to develop the condition.

Treatment for Caroli disease may include antibiotics to manage cholangitis, endoscopic procedures to remove stones or dilate strictures, and surgery to bypass or remove affected bile ducts. In severe cases, liver transplantation may be necessary. Regular monitoring of liver function and surveillance for complications are essential in the management of this condition.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

Mosaicism, in the context of genetics and medicine, refers to the presence of two or more cell lines with different genetic compositions in an individual who has developed from a single fertilized egg. This means that some cells have one genetic makeup, while others have a different genetic makeup. This condition can occur due to various reasons such as errors during cell division after fertilization.

Mosaicism can involve chromosomes (where whole or parts of chromosomes are present in some cells but not in others) or it can involve single genes (where a particular gene is present in one form in some cells and a different form in others). The symptoms and severity of mosaicism can vary widely, depending on the type and location of the genetic difference and the proportion of cells that are affected. Some individuals with mosaicism may not experience any noticeable effects, while others may have significant health problems.

Cerebrotendinous xanthomatosis is a rare inherited genetic disorder that affects the metabolism of cholesterol and bile acids. It is caused by mutations in the CYP27A1 gene, which provides instructions for making an enzyme called sterol 27-hydroxylase that plays a crucial role in the conversion of cholesterol to bile acids.

As a result of this enzyme deficiency, there is an accumulation of cholesterol and its derivatives (particularly cholestanol) in various tissues and body fluids, leading to the formation of xanthomas, which are yellowish, fatty deposits that can be found under the skin, around the eyes, or in tendons.

Cerebrotendinous xanthomatosis primarily affects the nervous system, particularly the brain (cerebro-) and the tendons (-tendinous). The neurological symptoms may include chronic diarrhea, seizures, intellectual disability, ataxia (loss of balance and coordination), psychiatric disorders, and pyramidal signs (such as muscle weakness, spasticity, and hyperreflexia).

The accumulation of cholestanol in the brain can lead to progressive neurological deterioration, while the tendon xanthomas are typically found in the Achilles tendons. The diagnosis of cerebrotendinous xanthomatosis is usually confirmed through genetic testing and biochemical tests that measure the levels of cholestanol and bile acids in the blood or other body fluids.

Early diagnosis and treatment with a medication called chenodeoxycholic acid, which helps to lower cholesterol levels and reduce xanthoma formation, can significantly improve the prognosis and quality of life for individuals with cerebrotendinous xanthomatosis.

Hermanski-Pudlak Syndrome (HPS) is a rare genetic disorder characterized by the triad of albinism, bleeding disorders, and lysosomal storage disease. It is caused by mutations in any one of several genes involved in biogenesis of lysosome-related organelles (LROs), such as melanosomes in melanocytes, platelet dense granules, and lung lamellar bodies.

The albinism in HPS results from abnormal melanosome biogenesis, leading to decreased pigmentation in the skin, hair, and eyes. The bleeding disorder is due to defective platelet dense granules, which are necessary for normal clotting function. This can result in prolonged bleeding times and easy bruising.

The lysosomal storage disease component of HPS is characterized by the accumulation of ceroid lipofuscin within LROs, leading to progressive damage to affected tissues. The most common form of HPS (HPS-1) also involves pulmonary fibrosis, which can lead to respiratory failure and death in the third or fourth decade of life.

There are currently seven known subtypes of HPS, each caused by mutations in different genes involved in LRO biogenesis. The clinical features and severity of HPS can vary widely between subtypes and even within families with the same genetic mutation.

Insertional mutagenesis is a process of introducing new genetic material into an organism's genome at a specific location, which can result in a change or disruption of the function of the gene at that site. This technique is often used in molecular biology research to study gene function and regulation. The introduction of the foreign DNA is typically accomplished through the use of mobile genetic elements, such as transposons or viruses, which are capable of inserting themselves into the genome.

The insertion of the new genetic material can lead to a loss or gain of function in the affected gene, resulting in a mutation. This type of mutagenesis is called "insertional" because the mutation is caused by the insertion of foreign DNA into the genome. The effects of insertional mutagenesis can range from subtle changes in gene expression to the complete inactivation of a gene.

This technique has been widely used in genetic research, including the study of developmental biology, cancer, and genetic diseases. It is also used in the development of genetically modified organisms (GMOs) for agricultural and industrial applications.

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

Retinal diseases refer to a group of conditions that affect the retina, which is the light-sensitive tissue located at the back of the eye. The retina is responsible for converting light into electrical signals that are sent to the brain and interpreted as visual images. Retinal diseases can cause vision loss or even blindness, depending on their severity and location in the retina.

Some common retinal diseases include:

1. Age-related macular degeneration (AMD): A progressive disease that affects the central part of the retina called the macula, causing blurred or distorted vision.
2. Diabetic retinopathy: A complication of diabetes that can damage the blood vessels in the retina, leading to vision loss.
3. Retinal detachment: A serious condition where the retina becomes separated from its underlying tissue, requiring immediate medical attention.
4. Macular edema: Swelling or thickening of the macula due to fluid accumulation, which can cause blurred vision.
5. Retinitis pigmentosa: A group of inherited eye disorders that affect the retina's ability to respond to light, causing progressive vision loss.
6. Macular hole: A small break in the macula that can cause distorted or blurry vision.
7. Retinal vein occlusion: Blockage of the retinal veins that can lead to bleeding, swelling, and potential vision loss.

Treatment for retinal diseases varies depending on the specific condition and its severity. Some treatments include medication, laser therapy, surgery, or a combination of these options. Regular eye exams are essential for early detection and treatment of retinal diseases.

Ciliary motility disorders are a group of rare genetic conditions that affect the function of cilia, which are tiny hair-like structures on the surface of cells in the body. Cilia play an important role in moving fluids and particles across the cell surface, including the movement of mucus and other substances in the respiratory system, the movement of eggs and sperm in the reproductive system, and the movement of fluid in the inner ear.

Ciliary motility disorders are caused by mutations in genes that are responsible for the proper functioning of cilia. These mutations can lead to abnormalities in the structure or function of cilia, which can result in a range of symptoms depending on the specific disorder and the parts of the body that are affected.

Some common symptoms of ciliary motility disorders include recurrent respiratory infections, chronic sinusitis, hearing loss, infertility, and situs inversus, a condition in which the major organs are reversed or mirrored from their normal positions. There are several different types of ciliary motility disorders, including primary ciliary dyskinesia, Kartagener syndrome, and immotile cilia syndrome.

Treatment for ciliary motility disorders typically involves addressing the specific symptoms and underlying causes of the disorder. This may include antibiotics to treat respiratory infections, surgery to correct structural abnormalities, or assisted reproductive technologies to help with infertility.

Myotonia is a condition characterized by the delayed relaxation of a muscle after voluntary contraction or electrical stimulation, resulting in stiffness or difficulty with relaxing the muscles. It's often associated with certain neuromuscular disorders such as myotonic dystrophy and myotonia congenita. The prolonged muscle contraction can cause stiffness, especially after periods of rest, and may improve with repeated contractions (warm-up phenomenon).

Genetic counseling is a process of communication and education between a healthcare professional and an individual or family, aimed at understanding, adapting to, and managing the medical, psychological, and familial implications of genetic contributions to disease. This includes providing information about the risk of inherited conditions, explaining the implications of test results, discussing reproductive options, and offering support and resources for coping with a genetic condition. Genetic counselors are trained healthcare professionals who specialize in helping people understand genetic information and its impact on their health and lives.

Linkage disequilibrium (LD) is a term used in genetics that refers to the non-random association of alleles at different loci (genetic locations) on a chromosome. This means that certain combinations of genetic variants, or alleles, at different loci occur more frequently together in a population than would be expected by chance.

Linkage disequilibrium can arise due to various factors such as genetic drift, selection, mutation, and population structure. It is often used in the context of genetic mapping studies to identify regions of the genome that are associated with particular traits or diseases. High levels of LD in a region of the genome suggest that the loci within that region are in linkage, meaning they tend to be inherited together.

The degree of LD between two loci can be measured using various statistical methods, such as D' and r-squared. These measures provide information about the strength and direction of the association between alleles at different loci, which can help researchers identify causal genetic variants underlying complex traits or diseases.

Skin abnormalities refer to any changes in the skin that deviate from its normal structure, function, or color. These can manifest as various conditions such as lesions, growths, discolorations, or textural alterations. Examples include moles, freckles, birthmarks, rashes, hives, acne, eczema, psoriasis, rosacea, skin cancer, and many others. Some skin abnormalities may be harmless and require no treatment, while others might indicate an underlying medical condition that requires further evaluation and management.

Recessive inheritance is when both matching genes must be abnormal to cause disease. If only one gene in the pair is abnormal, ... Only one of the Y chromosome genes, the SRY gene, is responsible for male anatomical traits. When any of the 9 genes involved ... An allele is either said to be dominant or recessive. Dominant inheritance occurs when an abnormal gene from one parent causes ... It is caused by a change in a gene called FMR1. A small part of the gene code is repeated on a fragile area of the X chromosome ...
This suggests that the curly gene is dominant. There are multiple theories for how the American Curly developed. The Curly ... and recessive genetic mutations.: 79 : 248 The coat is often heavily curled in winter, and much less so in summer; unusually, ... The genetic mechanism that causes the curly coat defect in horses is not fully understood; it involves both dominant (gene),]] ... the mane and tail also moult in summer.: 248 Some horses carry curly-coat genes but display little or curliness; their ...
Wachtel, Stephen S.; Basrur, Parvathi; Koo, Gloria C. (1978-09-01). "Recessive male-determining genes". Cell. 15 (1): 279-281. ... "Recessive male-determining genes" (1978, with Stephen S. Wachtel and Gloria C. Koo) "Morphological and hormonal features of an ...
... genes can cancel each other out, or "cross", removing all color and producing a white recessive gene, essentially a white ... Dapple genes, which are dominant genes, are considered "dilution" genes, meaning whatever color the dog would have originally ... "Recessive and Dominant Genes". Weatherly's Miniature Dachshunds. Retrieved 19 November 2009. Adamson, Eve (2007). Dachshunds ... "Brittle Bone" Gene in Dachshunds Discovered" (PDF). Newsletter. Dachshund Club of America. Archived (PDF) from the original on ...
Since this is an autosomal recessive disease, two copies of the gene that contain the mutation must be present for one to show ... It is of autosomal recessive inheritance. It may be caused by a mutation on the SLURP1 gene, located on chromosome 8. The ... A gene mutation would be caused by the chromosome 8qter, which codes for the SLURP1 gene, to be cut, thus causing a mutation in ... "Autosomal recessive inheritance pattern". Mayo Clinic. Retrieved 2019-12-14. "SLURP1 gene". Reference, Genetics Home. "SLURP1 ...
Bi-black is recessive. A bi-black Sheltie carries two bi-black genes; thus any dog with a bi-black parent is always bi-factored ... including the bi gene, the merling gene, the sable gene, and the tricolour gene. According to the College of Veterinary ... A tricolor with the merling gene. May have blue eyes. Bi-blue - blue and white. A bi-black with the merling gene. May have blue ... May be pure for sable (two sable genes) or may be tri-factored or bi-factored (carrying one sable gene and one tricolor or ...
It is a recessive gene. If there is only one copy of the gene, it has no effect on black, bay or chestnut horses. If there are ... is a dilution gene at the same locus as the cream gene, which somewhat resembles the cream gene and the champagne gene but is ... gene. The Pearl gene is also known to interact with the cream gene to enhance its effects and, in horses with only one copy of ... Initially, the gene in Paints and Quarter Horses was thought to be a different allele than that in the Iberian breeds, but ...
It is recessive to wild-type. The gene locus has the symbol op. The wild-type allele at this locus is notated op+ and the ... The Opaline gene is linked to other genes located on the X chromosome, i.e. to the genes of other sex-linked mutations. These ... Hens cannot be split for any sex-linked gene, so only cocks exist in Type I and Type II form. Daniels, T (30 Jan 1982), "The ... Hens cannot be split for Opaline (or any other sex-linked mutation). In cocks, because Opaline is recessive, the Opaline allele ...
To their shock, the non-Ginger parents of the Ginger kids, who each carry a recessive gene that has caused them to have Ginger ... Asians don't carry the recessive gene. I know a guy who's marrying a Japanese woman very soon for just that reason." This is an ... The father of the Ginger kids informs Kyle that marrying an Asian woman ensures that the recessive gene is not passed down, and ...
This is a simple recessive gene. DNA testing, known as "Optigen Testing", can identify dogs carrying the gene for progressive ... Juvenile dilated cardiomyopathy is a fatal condition caused by an autosomal recessive gene. Affected puppies die suddenly or ... "Normal" or "A" dogs do not carry the gene. "Carriers" or "B" dogs carry one copy of the gene and will not express the disease, ... but pass the gene to 50% of their offspring. "Affected" or "C" dogs have two copies of the progressive retinal atrophy gene and ...
It is recessive to wild-type. The gene locus has the symbol sl. The wild-type allele at this locus is notated sl+ and the Slate ... The Slate gene is linked to other genes located on the X chromosome, i.e. to the genes of other sex-linked mutations. These sex ... It seems to have been quite difficult to separate the Opaline and Slate genes and it was not until 1962 that A F Fullilove ... As the Slate mutation is a sex-linked recessive, presumably the cock was split for Slate. In a series of articles published in ...
Various genes involved in steroidogenesis In cases with hearing involvement (Perrault syndrome), the following genes are ... Autosomal recessive. BMP15, associated with X-linked form. EIF2B2, EIF2B4, and EIF2B5, responsible for protein production (see ... This type is also known as Perrault syndrome, an autosomal recessive disease affecting both sexes. Males present only with the ... eIF2). PSMC3IP, autosomal recessive; mutation reduces estrogen-induced transcription of this gene. ...
Chestnut is produced by a recessive gene. Unlike many coat colors, chestnut can be true-breeding; that is, assuming they carry ... For example, "dunalinos" are chestnuts with both the dun gene and one copy of the cream gene. Bay horses also have reddish ... This is not the same as the blue eyes and pink skin seen at birth in foals carrying the champagne gene. It is a genetic ... Red duns have a chestnut base coat with the dun gene (one or two copies). Their body color is pale, dusty tan shade that ...
The brown nose is a recessive gene. It is not as common as a black nose; some breeders believe the inclusion of brown noses in ... two ridge genes) from heterozygotes (R/r - one ridge gene) is available (www.genocan.eu/en). Using the genetic test, a breeder ... There is a DNA test available to test for the gene. Animals who are at risk for the disease should not be bred to other animals ... group of genes), which, when present, double the chances of a Rhodesian Ridgeback becoming hypothyroid due to lymphocytic ...
"Entrez Gene: DFNB31 deafness, autosomal recessive 31". Yap CC, Liang F, Yamazaki Y, et al. (2003). "CIP98, a novel PDZ domain ... Mutations in this gene, also known as WHRN, cause autosomal recessive deafness. Model organisms have been used in the study of ... Genes on human chromosome 9, Genes mutated in mice). ... 2006). "The DFNB31 gene product whirlin connects to the Usher ... 2002). "DFNB31, a recessive form of sensorineural hearing loss, maps to chromosome 9q32-34". Eur. J. Hum. Genet. 10 (3): 210-2 ...
In the recessive form, the DTDST gene, also known as SLC26A2, is mutated in almost 90% of the patients, causing diastrophic ... However, there is an autosomal recessive form. Associated genes include COL9A1, COL9A2, COL9A3, COMP, and MATN3. Types include ... All those genes are involved in the production of the extracellular matrix (ECM). The role of COMP gene remains unclear. It is ... a mutation cannot be identified in any of the five genes above, suggesting that mutations in other as-yet unidentified genes ...
". "E-Locus (Recessive Yellow, Melanistic Mask Allele)". www.animalgenetics.us. Retrieved 2017-11-08. Wu CC, Gupta T, Garcia V ... A gene is said to be polymorphic if more than one allele occupies that gene's locus within a population. In addition to having ... Most notably, the genes coding for the major histocompatibility complex (MHC) are in fact the most polymorphic genes known. MHC ... For example, a polymorphic variant of the gene encoding the enzyme CYP4A11, in which thymidine replaces cytosine at the gene's ...
... this is caused by a recessive gene. The Valle del Belice is one of the seventeen autochthonous Italian sheep breeds for which a ...
"Entrez Gene: Spastic paraplegia 23 (autosomal recessive)". "SPG23 Symbol Report , HUGO Gene Nomenclature Committee". www. ... Spastic paraplegia 23 (SPG autosomal recessive) is a 25cM gene locus at 1q24-q32. A genome-wide linkage screen has associated ... v t e (Articles with short description, Short description matches Wikidata, Human genes, Proteins, All stub articles, Human ...
Sainlar, Lindsay (11 September 2003). Robinson, Andrew (ed.). "Rare recessive gene makes Western's squirrels white". WKU Herald ... likely non-albino squirrels that exhibit a rare white fur coloration known as leucism that is as a result of a recessive gene ...
Autosomal recessive hearing loss is when both parents carry the recessive gene, and pass it on to their child. The autosomal ... Duman, Duygu; Tekin, Mustafa (2012-06-01). "Autosomal recessive nonsyndromic deafness genes: a review". Frontiers in Bioscience ... Most of genetic factors are caused by an autosomal recessive hearing loss or an autosomal dominant hearing loss. ... dominant hearing loss is when an abnormal gene from one parent is able to cause hearing loss even though the matching gene from ...
Additionally, recessive mutations of the gene result in both a loss of TMC1 function as well as profound deafness indicating ... Duman D, Tekin M (2012). "Autosomal recessive nonsyndromic deafness genes: a review". Front Biosci. 17 (7): 2213-36. doi: ... This gene is considered a member of a gene family predicted to encode transmembrane proteins. Until recently, the specific ... Keresztes G, Mutai H, Heller S (2003). "TMC and EVER genes belong to a larger novel family, the TMC gene family encoding ...
This is due to a recessive gene. British Alpine goats have a typical "wedge" shape that is predominant in some other breeds of ...
"Entrez Gene: Spastic paraplegia 14 (autosomal recessive)". Vazza G, Zortea M, Boaretto F, Micaglio GF, Sartori V, Mostacciuolo ... Spastic paraplegia 14 (autosomal recessive) is a protein that in humans is encoded by the SPG14 gene. "Human PubMed Reference ... v t e (Articles with short description, Short description matches Wikidata, Human genes, Proteins, All stub articles, Human ... ML (August 2000). "A new locus for autosomal recessive spastic paraplegia associated with mental retardation and distal motor ...
In phenotype, FVH1 is caused by a SLC38A8 gene mutation. FVH2 occurs by autosomal recessive inheritance. Both parents pass the ... There are four gene mutations that occur in albinism and are linked to macular hypoplasia. The four mutations can occur on the ... The most common gene mutation is the FH phenotype and has a 67.5% correlation rate to macular hypoplasia. The disorder can ... In phenotype FVH1, there is a mutation of the PAX6 gene. FVH1 occurs through autosomal dominant inheritance. The mutation is ...
The yotari mouse is an autosomal recessive mutant. It has a mutated disabled homolog 1 (Dab1) gene. This mutant mouse is ... 1997). "Scrambler and yotari disrupt the disabled gene and produce a reeler-like phenotype in mice". Nature. 389 (6652): 730-3 ...
"Entrez Gene: CIRH1A cirrhosis, autosomal recessive 1A (cirhin)". Sato M, Araki N, Kumeta M, Takeyasu K, Taguchi Y, Asai T, et ... UTP4 is a gene that encodes the protein Cirhin, the gene is also known as CIRH1A and NAIC. This protein contains a WD40 repeat ... July 2000). "Localization of a recessive gene for North American Indian childhood cirrhosis to chromosome region 16q22-and ... Human UTP4 genome location and UTP4 gene details page in the UCSC Genome Browser. v t e (Articles with short description, Short ...
The ATP13A2 gene is located on chromosome 1 (1p36.13). The ATP13A2 gene is located in position 36 on the p-arm, which is the ... The inheritance pattern for KRS is autosomal recessive. If a male and female carrier, who each have one mutation in ATP13A2 ... The ATP13A2 gene mutations associated with KRS are truncated forms and cause protein instability with loss-of-function. The ... ATP13A2 gene mutations are associated with Kufor-Rakeb syndrome, first identified in 2010. This syndrome is identified to have ...
"Entrez Gene: CENPE centromere protein E, 312kDa". "OMIM Entry - # 616051 - MICROCEPHALY 13, PRIMARY, AUTOSOMAL RECESSIVE; ... 2005). "Gene silencing of CENP-E by small interfering RNA in HeLa cells leads to missegregation of chromosomes after a mitotic ... Centromere-associated protein E is a protein that in humans is encoded by the CENPE gene. Centromere-associated protein E is a ... Testa JR, Zhou JY, Bell DW, Yen TJ (Mar 1995). "Chromosomal localization of the genes encoding the kinetochore proteins CENPE ...
This complementation is rare with autosomal recessive inheritance. The inherited methionine synthase functional deficiency ... The exact MTRR gene location was mapped to 5p15.3-p15.2. The MTRR gene is associated with a family of electron transferases ... Exact gene cytogenic position was determined by mapping to an artificial chromosomal construct containing the gene via ... Gene. 629: 59-63. doi:10.1016/j.gene.2017.07.081. PMID 28778621. G">"NM_002454.2(MTRR):c.1049A>G (p.Lys350Arg) AND not ...
... in rat model shows that a recessive mutation in a receptor tyrosine kinase gene, mertk results in a premature stop codon and ... Immune response to gene therapy vectors is what has caused previous attempts at gene therapy to fail, and is considered a key ... In retinal gene therapy, the most widely used vectors for ocular gene delivery are based on adeno-associated virus. The great ... Retina Gene therapy Retinitis pigmentosa Macular degeneration Gene therapy for color blindness Maguire A. M.; Simonelli F.; ...
2000). "Mapping of a new locus for autosomal recessive demyelinating Charcot-Marie-Tooth disease to 19q13.1-13.3 in a large ... Periaxin is a protein that in humans is encoded by the PRX gene. The PRX gene encodes L- and S-periaxin, proteins of ... Genes on human chromosome 19, All stub articles, Human chromosome 19 gene stubs). ... "Entrez Gene: PRX periaxin". Sherman DL, Brophy PJ (2000). "A tripartite nuclear localization signal in the PDZ-domain protein L ...
This gene is located on the short arm of chromosome 3 (3p21.3). The inheritance of this condition is autosomal recessive. The ... It is caused by the mutation of the P4HTM gene on chromosome 3. This syndrome causes intellectual disability and affects the ... It is made by sequencing the P4HTM gene. There is presently no curative treatment. Management is supportive. The prevalence is ... This condition is caused by mutations in the Prolyl 4-hydroxylase, transmembrane (P4HTM) gene. ...
... Ann Saudi Med. 2016 Nov-Dec;36 ... Main outcome measure(s): Detection of mutation in the ASPM gene in a family segregating autoso- mal recessive primary ... To date, 17 genes have been known as an underlying cause of MCPH in humans. ASPM (abnormal spindle-like, microcephaly ... Results: A novel homozygous splice-site variant (c.3742-1G , C) in the ASPM gene was identified. The variant is predicted to ...
An autosomal recessive form of juvenile Parkinsonism (AR-JP) (MIM 600116) is a levodopa-responsive Parkinsonism whose ... Localization of a gene for an autosomal recessive form of juvenile Parkinsonism to chromosome 6q25.2-27 Am J Hum Genet. 1997 ... An autosomal recessive form of juvenile Parkinsonism (AR-JP) (MIM 600116) is a levodopa-responsive Parkinsonism whose ... By linkage analysis of diallelic polymorphism of the Mn-superoxide dismutase gene (SOD2), we found a family with AR-JP showing ...
Study of the involvement of the RGR, CRPB1, and CRB1 genes in the pathogenesis of autosomal recessive retinitis pigmentosa ... Study of the involvement of the RGR, CRPB1, and CRB1 genes in the pathogenesis of autosomal recessive retinitis pigmentosa ... Previous studies performed in autosomal recessive retinitis pigmentosa (ARRP) Spanish families have shown that genes coding for ... However, mutations in the beta subunit of the rod cGMP-phosphodiesterase gene,8-11 in the ATP binding cassette receptor gene,12 ...
G o o g l e ™ Scholar:others by: Gene editing-based protocols for the ex vivo correction of Recessive Dystrophic Epidermolysis ... Gene editing-based protocols for the ex vivo correction of Recessive Dystrophic Epidermolysis Bullosa. Author(s): Bonafont ... Gene editing-based protocols for the ex vivo correction of Recessive Dystrophic Epidermolysis Bullosa. e-Archivo Repository. ... A frame-shift mutation (c.6527insC) in the exon 80 of COL7A1 gene is present in 46% of the Spanish population of patients with ...
Autosomal recessive axonal neuropathy with neuromyotonia is a disorder that affects the peripheral nerves. Explore symptoms, ... Autosomal recessive axonal neuropathy with neuromyotonia is caused by mutations in the HINT1 gene. This gene provides ... HINT1 gene mutations that cause autosomal recessive axonal neuropathy with neuromyotonia lead to production of a HINT1 protein ... This condition is inherited in an autosomal recessive pattern. , which means both copies of the gene in each cell have ...
... which are present in both copies of a gene, researchers have identified four autism candidates that may be involved in… ... Genetics: Search for recessive mutations reveals autism genes. by Jessica Wright / 30 May 2012 ... By screening for recessive mutations, which are present in both copies of a gene, researchers have identified four autism ... TAGS: AGRE, autism, de novo mutations, exome, gene expression, rare variants, sequencing, SNPs, whole-exome sequencing ...
Recessive" by people in this website by year, and whether "Genes, Recessive" was a major or minor topic of these publications. ... "Genes, Recessive" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical Subject ... Novel candidate genes and variants underlying autosomal recessive neurodevelopmental disorders with intellectual disability. ... ADAMTS1, MPDZ, MVD, and SEZ6: candidate genes for autosomal recessive nonsyndromic hearing impairment. Eur J Hum Genet. 2022 01 ...
Autosomal recessive polycystic kidney disease (ARPKD) is the most common heritable cystic renal disease occurring in infancy ... Polycystic Kidney Disease, Autosomal Recessive. Adam MP, Ardinger HH, Pagon RA, et al.,. Gene Reviews. University of Washington ... Autosomal Recessive Polycystic Kidney Disease (ARPKD) Imaging * Sections Autosomal Recessive Polycystic Kidney Disease (ARPKD) ... encoded search term (Autosomal Recessive Polycystic Kidney Disease (ARPKD) Imaging) and Autosomal Recessive Polycystic Kidney ...
Autosomal recessive omodysplasia. Synonyms: Micromelic dysplasia-dislocation of radius syndrome. Related Disorders. ... Autosomal recessive omodysplasia?. Our RARE Concierge Services Guides are available to assist you by providing information, ... Donate to Global Genes 28 Argonaut, Suite 150. Aliso Viejo, CA 92656. Phone: (+1) 949-248-RARE (7273) ... Autosomal recessive omodysplasia. Get in touch with RARE Concierge.. Contact RARE Concierge ...
Autosomal recessive hypophosphatemic rickets. Synonyms: ARHR. A rare autosomal recessive renal phosphate-wasting disorder ... Autosomal recessive hypophosphatemic rickets?. Our RARE Concierge Services Guides are available to assist you by providing ... Autosomal recessive hypophosphatemic rickets. Get in touch with RARE Concierge.. Contact RARE Concierge ... Donate to Global Genes 28 Argonaut, Suite 150. Aliso Viejo, CA 92656. Phone: (+1) 949-248-RARE (7273) ...
Mapping of SrTm4, a recessive stem rust resistance gene from diploid wheat effective to Ug99. Phytopathology. 2015 Oct 1;105(10 ... Mapping of SrTm4, a recessive stem rust resistance gene from diploid wheat effective to Ug99. In: Phytopathology. 2015 ; Vol. ... Dive into the research topics of Mapping of SrTm4, a recessive stem rust resistance gene from diploid wheat effective to Ug99 ... Mapping of SrTm4, a recessive stem rust resistance gene from diploid wheat effective to Ug99. / Briggs, Jordan; Chen, Shisheng ...
Our genetics experts explain how genes are passed from one generation to the next and why traits may skip a generation. ... Dominant Genes vs. Recessive Genes. Alleles can be dominant (strong) or recessive (weak). Using eye color as our example, the ... An example of a recessive genetic disorder is cystic fibrosis. This condition is caused by a faulty gene, the CFTR gene ... If two carriers of the CFTR gene mutation have a baby together there is a 25% chance that they will both pass on the recessive ...
WE WERE NOT CREATED WITH YOUR WEAK RECESSIVE GENES!. Date: December 13, 2019. ...
Recessive inheritance is when both matching genes must be abnormal to cause disease. If only one gene in the pair is abnormal, ... Only one of the Y chromosome genes, the SRY gene, is responsible for male anatomical traits. When any of the 9 genes involved ... An allele is either said to be dominant or recessive. Dominant inheritance occurs when an abnormal gene from one parent causes ... It is caused by a change in a gene called FMR1. A small part of the gene code is repeated on a fragile area of the X chromosome ...
Mutations in the lipase member H (LIPH) gene cause autosomal recessive hypotrichosis with woolly hair. We report herein on five ... A novel mutation in the Lipase H gene underlies autosomal recessive hypotrichosis and woolly hair. ... Sequence analysis of the LIPH gene revealed a novel nonsense mutation (p.Arg260X) associated with hypotrichosis without woolly ...
Immune reactivity to type VII collagen: implications for gene therapy of recessive dystrophic epidermolysis bullosa. ... Home Immune reactivity to type VII collagen: implications for gene therapy of recessive dystrophic epidermolysis bullosa ... Immune reactivity to type VII collagen: implications for gene therapy of recessive dystrophic epidermolysis bullosa. ...
Recessive Genes / Faults When assessing your rearing stock and noticing an obvious fault, it can be very disheartening. An ... The Dominant White Gene The word gene is enough to put many people off when it comes to poultry articles. However, let me ... The Lavender Gene The lavender variety of poultry is very beautiful. The effect is born from the lavender gene being present in ... When learning about how Gold and Silver genes work in poultry, it can be very gratifying to realise that much can be made of ...
Autosomal recessive osteopetrosis 2 MedGen: C1850126 OMIM: 259710 GeneReviews: Not available Compare labs ... Gene neighbors Overlapping genes and two nearest non-overlapping genes on either side ... Gene Ontology Provided by GOA Function. Evidence Code. Pubs. enables cytokine activity IDA Inferred from Direct Assay. more ... Gene. Interaction. Pubs. Envelope surface glycoprotein gp120 env HIV-1 gp120 reduces osteoblast function and significantly ...
Autosomal recessive. Genes. There are currently 20 retinal genes whose mutations cause the phenotype of LCA, accounting for ... CEP290 gene (NPHP6, OMIM# 610142) causes SLSN6 (OMIM# 610189). CEP290 gene (aka NPHP6 OMIM# 610142) causes JBTS5 (OMIM# 610188 ... Hum Gene Ther. 2011; 22:1179-1190.. *Acland GM, Aguirre GD, Ray J, et al. Gene therapy restores vision in a canine model of ... WDR19 gene (OMIM# 608151) causes SLSN8 (OMIM# 616307). WD repeat-containing protein 19, aka DYF-2 (in elegans) is expressed in ...
The DJ-1 gene encodes a ubiquitous, highly conserved protein. Here, we show that DJ-1 mutations are associated with PARK7, a ... Mutations in the DJ-1 gene associated with autosomal recessive early-onset parkinsonism. ... Mutations in the DJ-1 gene associated with autosomal recessive early-onset parkinsonism. ... Genes, Recessive, Mutation, Point Mutation, Alleles, Exons, Molecular Sequence Data, Protein Deglycase DJ-1 ...
Clinical Molecular Genetics test for Autosomal recessive nonsyndromic hearing loss 28 and using Deletion/duplication analysis, ... Deafness, Autosomal Recessive 28 (DFNB28) via the TRIOBP Gene. *GTR Test IDHelpEach Test is a specific, orderable test from a ... Deafness, Autosomal Recessive 28 (DFNB28) via the TRIOBP Gene. Purpose of the test HelpPurposes or indications for the test. ... GTR Home , Tests , Deafness, Autosomal Recessive 28 (DFNB28) via the TRIOBP Gene ...
Post-Flood mutations in the KIT gene have contributed to the rise of a variety of white coloration patterns in animals and ... The first was considered worthy of further investigation in potentially being associated with the recessive white phenotype in ... The NCBI Gene Database, preview.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=retrieve&dopt=full_report&list_uids=396810&log$= ... The NCBI Gene Database, preview.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=retrieve&dopt=full_report&list_uids=100009704&log$= ...
Find symptoms and other information about Autosomal recessive multiple pterygium syndrome. ... What Is a Gene?. Understanding what genes are and how changes in genes may affect the body can help you on the journey to ... Autosomal recessive multiple pterygium syndrome is a genetic disease, which means that it is caused by one or more genes not ... Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.. ...
KEY MESSAGE The diploid wheat recessive stem rust resistance gene SrTm4 was fine-mapped to a 754-kb region on chromosome arm ... High-resolution mapping of SrTm4, a recessive resistance gene to wheat stem rust. ... High-resolution mapping of SrTm4, a recessive resistance gene to wheat stem rust. ... In this study, we generated SrTm4 monogenic lines and found that this gene confers resistance to North American and Chinese Pgt ...
Pulmonary hypertension, primary, autosomal recessive MedGen: C5676877 OMIM: 265400 GeneReviews: Not available ... Gene neighbors Overlapping genes and two nearest non-overlapping genes on either side ... Cloning the AFURS1 gene which is up-regulated in senescent human parenchymal kidney cells. Habtemichael N, et al. Gene, 2002 ... Observational study of gene-disease association. (HuGE Navigator) Title: Gene-centric association signals for lipids and ...
In rare cases, Sarc− HCM cases may be caused by pathogenic variants in non-sarcomeric genes. The aim of this review is to ... in whom the causal mutation is identified in a sarcomeric gene; and sarcomeric-negative (Sarc−) patients, in whom a causal ... HCM is inherited as an autosomal dominant trait and, in about 40% of patients, the causal mutation is identified in genes ... AD: autosomal dominant; AR: autosomal recessive.. Gene. Function of the Encoded Protein. Level of Evidence for HCM Association ...
The recessive genes that make a carrot orange. A new study of the genetic blueprints of more than 600 types of carrot shows ... Surprisingly, these three required genes all need to be recessive, or turned ... ... North Carolina State University researchers have successfully transferred an important gene from one compartment of a plant ... that three specific genes are required to give carrots an orange color. ...
Although high IgE levels were found to be determined by a recessive major gene in several studies, other modes of inheritance ... In addition, no interaction between this major gene and SRA is shown here. Our results suggest that this gene, which accounts ... the familial transmission of total IgE level is compatible with the segregation of a recessive major gene and residual familial ... there is still evidence for a recessive major gene controlling IgE levels but residual familial correlations are no longer ...
Whole exome sequencing analysis revealed a novel homozygous missense variant (c.98807G > A; p.Arg32936His) in the TTN gene ... Our study concludes that WES is a successful molecular diagnostic tool to identify pathogenic variants in large genes such as ... Pathogenic mutations in the gene encoding the giant skeletal muscle protein titin (TTN) are associated with several muscle ... This study aimed to identify the pathogenic variant in a consanguineous Pakistani family with autosomal recessive LGMD type 10 ...
  • Detection of mutation in the ASPM gene in a family segregating autoso- mal recessive primary microcephaly. (nih.gov)
  • A frame-shift mutation (c.6527insC) in the exon 80 of COL7A1 gene is present in 46% of the Spanish population of patients with RDEB. (uc3m.es)
  • A novel mutation in the Lipase H gene underlies autosomal recessive hypotrichosis and woolly hair. (scilifelab.se)
  • Sequence analysis of the LIPH gene revealed a novel nonsense mutation (p.Arg260X) associated with hypotrichosis without woolly hair in one family. (scilifelab.se)
  • 1 Some of these, such as the MC1R 2 and ASIP 3 genes, have been fairly well studied and useful information has been obtained by examining mutation patterns at these loci. (creation.com)
  • HCM is inherited as an autosomal dominant trait and, in about 40% of patients, the causal mutation is identified in genes encoding sarcomere proteins. (mdpi.com)
  • In this study, we documented a clinical and molecular investigation of a consanguineous Pakistani family segregating LGMD in an autosomal recessive form and identified a novel homozygous missense mutation in the TTN gene located on chromosome 2q31.2. (biomedcentral.com)
  • To the best of our knowledge the molecular studies on mutation in the TTN gene is reported for the first time from Pakistan. (biomedcentral.com)
  • A mutation in the XPB/ERCC3 DNA repair transcription gene, associated with trichothiodystrophy. (nature.com)
  • Recessive mutation in desmoplakin disrupts desmoplakin-intermediate filament interactions and causes dilated cardiomyopathy, woolly hair and keratoderma. (nature.com)
  • The mutation followed a Mendalian pattern with an autosomal recessive inheritance mode. (illumina.com)
  • One or both of the genes in a pair can carry a mutation and fail to function properly. (healthwise.net)
  • In an autosomal recessive condition, both chromosomes in a pair must have a mutation for the person to have the disease. (healthwise.net)
  • If only one gene carries a mutation, the person is a carrier of the condition but does not have any symptoms. (healthwise.net)
  • A 25% chance in each pregnancy that their child will inherit the mutation from each parent (two genes) and have the condition. (healthwise.net)
  • Sometimes, a genetic mutation occurs on its own (spontaneous), so that neither parent has a copy of the mutated gene. (mayoclinic.org)
  • It can occur due to a mutation in over 50 different genes responsible for carrying the instructions on making proteins required in photoreceptors. (medicalnewstoday.com)
  • When a biological parent carries the gene mutation on the dominant version of a gene, the child only needs one copy of the mutation to develop RP. (medicalnewstoday.com)
  • What today is recognized as the Levine-Critchley syndrome is caused by a mutation in a specific gene called chorein (also called VPS13A ). (medscape.com)
  • it is caused by a mutation in the PKHD1 gene, located in chromosome 6p21. (msdmanuals.com)
  • Identification of a double mutation (D160V-K161E) in the p67phox gene of a chronic granulomatous disease patient. (lu.se)
  • A mutation located at the 5' splice junction sequence of intron 3 in the p67phox gene causes the lack of p67phox mRNA in a patient with chronic granulomatous disease. (lu.se)
  • Mutation analysis of the TBCE gene of this syndrome was shown to be due to Polymerase chain reaction/single-strand mutations in the TBCE gene in chromosom- conformation polymorphism analysis and al area 1q42-q43 [ 4,5 ]. (who.int)
  • Although high IgE levels were found to be determined by a recessive major gene in several studies, other modes of inheritance were also reported. (ox.ac.uk)
  • ORs and their reported 95% confidence interval (CI) for dominant and recessive inheritance models were extracted from final retrieved studies. (waocp.com)
  • The contributions of these multiple genes to most common diseases can be captured under the heading of polygenic inheritance , in which additive effects of numerous genes create a normal distribution of disease risk in the population that can be quantified using additive genetic risk scores. (cdc.gov)
  • This study describes its clinical spectrum, management outcomes and genetic associations in patients with autosomal recessive RP (arRP). (lu.se)
  • Genotype-phenotype correlations and nephroprotective effects of RAAS inhibition in patients with autosomal recessive Alport syndrome. (cdc.gov)
  • The aim of this meta-analysis was to discover the effect of dominant and recessive genetic models of LSP1 gene rs3817198 polymorphism on breast cancer risk. (waocp.com)
  • Retinitis pigmentosa (RP), which occurs in about 1 in 3000-7000 people in Spain, is inherited in an autosomal dominant manner in 12% of cases, in an autosomal recessive way in 39%, and in an X linked manner in 4% of cases. (bmj.com)
  • It tends to be inherited in an autosomal recessive fashion. (nih.gov)
  • DFNA11 is inherited in an autosomal dominant pattern, which means only one mutated copy of the MYO7A gene in each cell is sufficient to cause the condition. (medlineplus.gov)
  • DFNB2 is inherited in an autosomal recessive pattern, which means both copies of the MYO7A gene are mutated in each cell. (medlineplus.gov)
  • [ 5 ] DTDST is inherited in an autosomal recessive manner. (medscape.com)
  • By extending the linkage analysis to 13 families with AR-JP, we discovered strong evidence for the localization of the AR-JP gene at chromosome 6q25.2-27, including the SOD2 locus, with the maximal cumulative pairwise LOD scores of 7.26 and 7.71 at D6S305 (theta = .03) and D6S253 (theta = .02), respectively. (nih.gov)
  • The deactivated X chromosome is silenced by repressive heterochromatin that compacts the DNA and prevents expression of most genes. (wikipedia.org)
  • There is a gene in the Y chromosome that has regulatory sequences that control genes that code for maleness, called the SRY gene. (wikipedia.org)
  • KEY MESSAGE The diploid wheat recessive stem rust resistance gene SrTm4 was fine-mapped to a 754-kb region on chromosome arm 2AmL and potential candidate genes were identified. (bvsalud.org)
  • Viruses could tinker with gene structure, in many settings, exerting largely the same effects in males and females at the same time and at the same point on the chromosome, and do so to large numbers at once, and produce a large cluster of organisms that can breed with each other but not with the parent stock. (behavior.net)
  • Each chromosome contains genes. (healthwise.net)
  • X-linked hypophosphatemic rickets and autosomal recessive hypophosphatemic rickets are the result of mutations in PHEX (a phosphate-regulating gene with homologies to endopeptidases on the X chromosome) and dentin matrix protein 1 ( DMP1 ), respectively. (medscape.com)
  • This means that the mutated gene is on the X chromosome. (medicalnewstoday.com)
  • This gene, which codes for a sulfate transporter protein, has been mapped to distal end of chromosome bands 5q31-q34. (medscape.com)
  • Regions of chromosomes that carry an identical genetic sequence from each parent are likely to harbor recessive mutations. (spectrumnews.org)
  • The human sex chromosomes, a typical pair of mammal allosomes, carry the genes that determine the sex of an individual created in sexual reproduction. (wikipedia.org)
  • Autosomes are homologous chromosomes i.e. chromosomes which contain the same genes (regions of DNA) in the same order along their chromosomal arms. (wikipedia.org)
  • Autosomal recessive conditions are genetic diseases that are passed to a child through both parents' chromosomes. (healthwise.net)
  • These conditions are described as genetic diseases because a defect in one or more genes or chromosomes leads to a pathological condition. (who.int)
  • The large number of RP genes identified can be grouped into a number of functional classes: (1) proteins of the visual cascade, (2) proteins of the visual cycle, (3) photoreceptor cell transcription factors, (4) proteins related to catabolic processes, and (5) genes of unknown function. (bmj.com)
  • In 4 of the 16 individuals, the researchers found recessive mutations that affect brain-related proteins. (spectrumnews.org)
  • These genes code for proteins that form the sex organs in flowers. (wikipedia.org)
  • Mutations in these genes affect proteins involved in the signaling pathway for pigment production and explain a large amount of the color variation in mammals. (creation.com)
  • The MYO7A gene provides instructions for making a protein called myosin VIIA, which is part of a group of proteins called unconventional myosins. (medlineplus.gov)
  • In an autosomal dominant disorder, the changed gene is a dominant gene. (mayoclinic.org)
  • A person with an autosomal dominant disorder - in this example, the father - has a 50% chance of having an affected child with one changed gene. (mayoclinic.org)
  • Studies indicate that approximately 20% of RP cases may be autosomal recessive, 10-20% autosomal dominant, 10% X-linked recessive, and the rest sporadic. (medicalnewstoday.com)
  • Potential Founder Variants in COL4A4 Identified in Bukharian Jews Linked to Autosomal Dominant and Autosomal Recessive Alport Syndrome. (cdc.gov)
  • By screening for recessive mutations, which are present in both copies of a gene, researchers have identified four autism candidates that may be involved in neuronal signaling, according to a study published 12 April in PLoS Genetics 1 . (spectrumnews.org)
  • Our genetics experts explain how genes are passed from one generation to the next and why traits may skip a generation. (familyeducation.com)
  • as with a lot of things when it comes to genetics, in reality, eye color is more complicated than this as it is not inherited via a single gene but multiple ones that all interact with each other. (familyeducation.com)
  • As a result of the rapid advances in genetics technology and the Human Genome Project, most of the estimated 100,000 genes in humans will be identified by the year 2005 (1). (cdc.gov)
  • Disparities in discovery of pathogenic variants for autosomal recessive non-syndromic hearing impairment by ancestry. (ucdenver.edu)
  • In rare cases, Sarc− HCM cases may be caused by pathogenic variants in non-sarcomeric genes. (mdpi.com)
  • Our study concludes that WES is a successful molecular diagnostic tool to identify pathogenic variants in large genes such as TTN in highly inbred population. (biomedcentral.com)
  • HINT1 gene mutations that cause autosomal recessive axonal neuropathy with neuromyotonia lead to production of a HINT1 protein with little or no function. (medlineplus.gov)
  • Mutations in the lipase member H (LIPH) gene cause autosomal recessive hypotrichosis with woolly hair. (scilifelab.se)
  • Variants in KIAA0825 underlie autosomal recessive postaxial polydactyly. (ucdenver.edu)
  • Table 1 summarizes the association between genetic variants of autophagy-related genes and selected human diseases. (nature.com)
  • In the past two decades, however, genome-wide association studies (GWAS) have uncovered many variants throughout the human genome in multiple genes, each with modest increased risk (e.g., relative risks of 1.1 or 1.2) acting together and along with environmental factors to cause common diseases. (cdc.gov)
  • Genetic variants in TNFa, TGFB1, PTGS1 and PTGS2 genes are associated with diisocyanate -induced asthma. (cdc.gov)
  • A case-control study was conducted to investigate whether genetic variants in inflammatory response genes (TNFa, IL1a, IL1B, IL1RN, IL10, TGFB1, ADAM33, ALOX-5, PTGS1, PTGS2 and NAG-1/GDF15) are associated with increased susceptibility to diisocyanate asthma (DA). (cdc.gov)
  • Heterozygous Urinary Abnormality-Causing Variants of COL4A3 and COL4A4 Affect Severity of Autosomal Recessive Alport Syndrome. (cdc.gov)
  • Blue squares indicate phenotypes directly attributed to mutations/alleles of this gene. (jax.org)
  • There are now 320 single-gene inborn errors of immunity underlying phenotypes as diverse as infection, malignancy, allergy, auto-immunity, and auto-inflammation. (springer.com)
  • These genes were selected based on their role in asthmatic inflammatory processes and previously reported associations with asthma phenotypes. (cdc.gov)
  • Of these mediators, cytokines play a single nucleotide polymorphisms (SNP) in pro-inflammatory cytokine genes and asthma phenotypes (Che et al. (cdc.gov)
  • Our findings indicate that disruption of P2RY5 underlies ARWH and, more broadly, uncover a new gene involved in determining hair texture in humans. (nature.com)
  • The interaction of genes with each other and with environmental factors underlies many aspects of human health and disease. (who.int)
  • Pathogenic mutations in the gene encoding the giant skeletal muscle protein titin (TTN) are associated with several muscle disorders, including cardiomyopathy, recessive congenital myopathies and limb-girdle muscular dystrophy (LGMD) type10. (biomedcentral.com)
  • The prevalence of autosomal recessive muscle disorders like LGMD and congenital muscular dystrophies are rare in Pakistani populations. (biomedcentral.com)
  • Such factors include a tradition of consanguineous marriage , which results in a higher rate of autosomal recessive conditions including congenital malformations, stillbirths, or mental retardation. (who.int)
  • However, other individuals diagnosed with DFNB2 never develop retinitis pigmentosa, and recent studies indicate that DFNB2 and Usher syndrome probably result from different mutations in the MYO7A gene. (medlineplus.gov)
  • The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. (medlineplus.gov)
  • Newly diagnosed with Autosomal recessive hypophosphatemic rickets? (globalgenes.org)
  • To date, 17 genes have been known as an underlying cause of MCPH in humans. (nih.gov)
  • This gene produces a testis-determining factor ("TDF"), which initiates testis development in humans and other mammals. (wikipedia.org)
  • An enzyme that in humans encoded by the TPP1 gene. (bvsalud.org)
  • An autosomal recessive form of juvenile Parkinsonism (AR-JP) (MIM 600116) is a levodopa-responsive Parkinsonism whose pathological finding is a highly selective degeneration of dopaminergic neurons in the zona compacta of the substantia nigra. (nih.gov)
  • Mutations in the DJ-1 gene associated with autosomal recessive early-onset parkinsonism. (ox.ac.uk)
  • However, direct evidence of the connections between ATG gene dysfunction and human diseases has emerged only recently. (nature.com)
  • There are an increasing number of reports showing that mutations in the ATG genes were identified in various human diseases such as neurodegenerative diseases, infectious diseases, and cancers. (nature.com)
  • Here, we review the major advances in identification of mutations or polymorphisms of the ATG genes in human diseases. (nature.com)
  • Indeed, genome-wide studies have identified disease-associated loci and genes in many human diseases. (nature.com)
  • Autosomal recessive diseases include Tay-Sachs disease, cystic fibrosis, sickle cell disease, autosomal recessive polycystic kidney disease (ARPKD), and phenylketonuria (PKU). (healthwise.net)
  • As in many other diseases, there is considerable clinical heterogeneity in these syndromes, which may be caused by environmental interactions as well as the background of other genes and other diseases in the patient. (medscape.com)
  • Increased knowledge of genomics over the past two decades has made it apparent that the traditional category of genetic diseases represents only those conditions in which the genetic contribution is particularly marked, whereas in fact diseases can be arrayed along a spectrum representing the varied contribution of genes and the environment. (who.int)
  • Others can arise from the presence of an abnormal gene in any autosome: if the gene is dominant, it results always in what is called a dominant condition, whereas if it is recessive many of these diseases appear only when the gene is inherited from both parents (and are thus called recessive conditions). (who.int)
  • Salamon, T. Über eine Familie mit recessiver Kraushaarigkeit, Hypotrichose und anderen Anomalien [On a family with the recessive trait of woolly hair, hypotrichosis and other anomalies]. (nature.com)
  • Taking a more scientific approach, we can explain this by considering that many genes come in different versions, also called alleles. (familyeducation.com)
  • Alleles can be dominant (strong) or recessive (weak). (familyeducation.com)
  • Ginger or red hair is caused by inheriting two recessive alleles. (familyeducation.com)
  • Autosomal recessive primary microcephaly (MCPH) is a clinically and genetically heterogeneous disorder. (nih.gov)
  • Autosomal recessive axonal neuropathy with neuromyotonia is a disorder that affects the peripheral nerves. (medlineplus.gov)
  • A rare autosomal recessive renal phosphate-wasting disorder characterized by childhood-onset hypophosphatemia that clinically manifests with rickets and/or osteomalacia slow growth/short stature bone pain and skeletal deformities. (globalgenes.org)
  • Genetic changes in the CHRNG gene cause most cases of this disorder. (nih.gov)
  • Specifically, MYO7A gene mutations cause a form of the disorder known as Usher syndrome type IB (USH1B), which accounts for more than half of all cases of Usher syndrome type I. (medlineplus.gov)
  • You need only one changed gene to be affected by this type of disorder. (mayoclinic.org)
  • To have an autosomal recessive disorder, you inherit two changed genes, sometimes called mutations. (mayoclinic.org)
  • If both parents carry a gene for this disorder, each child has a 25% chance of getting the disease. (mayoclinic.org)
  • OMIM 241410)] is an authors (to avoid confusion and to main- autosomal recessive disorder first reported tain consistency). (who.int)
  • Recognition of a single-gene disorder as causal for a patient's 'multiple sclerosis-like' phenotype is critically important for accurate direction of patient management, and evokes broader genetic counselling implications for affected families. (medscape.com)
  • Here we review single gene disorders that have the potential to mimic multiple sclerosis, provide an overview of clinical and investigational characteristics of each disorder, and present guidelines for when clinicians should suspect an underlying heritable disorder that requires diagnostic confirmation in a patient with a definite or probable diagnosis of multiple sclerosis. (medscape.com)
  • Diastrophic dysplasia is an autosomal recessive disorder and occurs with equal frequency in males and females. (medscape.com)
  • The different genes that have been implicated in retinal degeneration are known or assumed to be expressed in the photoreceptor cells of the retina or in the retinal pigment epithelium (RPE). (bmj.com)
  • There are currently 20 retinal genes whose mutations cause the phenotype of LCA, accounting for about 70% of the cases, while the genes underlying the remaining 30% of patients await discovery. (aao.org)
  • Among the different subtypes described, the Recessive Dystrophic Epidermolysis Bullosa (RDEB) is the most severe subtype, with an increased risk of developing squamous cell carcinoma (SCC). (uc3m.es)
  • The DJ-1 gene encodes a ubiquitous, highly conserved protein. (ox.ac.uk)
  • This complex gene codes for a complex protein important in a number of pathways. (creation.com)
  • This complex organization of the gene reflects the complex nature of the protein receptor it produces. (creation.com)
  • In all cases, we discovered pathogenic mutations in P2RY5 , which encodes a G protein-coupled receptor and is a nested gene residing within intron 17 of the retinoblastoma 1 ( RB1 ) gene. (nature.com)
  • Leukocyte-specific protein 1 (LSP1) gene is located on 11p15.5 and encodes an F-actin binding protein. (waocp.com)
  • Other genetic changes delete a small amount of DNA from critical regions of the MYO7A gene, which probably changes the structure of the protein. (medlineplus.gov)
  • The researchers also sequenced the four candidate genes in another 418 individuals with autism and 371 controls, all from the ARRA Autism Sequencing Collaborative. (spectrumnews.org)
  • A Combined Targeted and Whole Exome Sequencing Approach Identified Novel Candidate Genes Involved in Heritable Pulmonary Arterial Hypertension. (nih.gov)
  • Several single gene disorders share clinical and radiologic characteristics with multiple sclerosis and have the potential to be overlooked in the differential diagnostic evaluation of both adult and paediatric patients with multiple sclerosis. (medscape.com)
  • Recently, precise gene modification technologies based on genomic nucleases have been developed, such as TALENs and CRISPR/Cas9. (uc3m.es)
  • Recessive Genome-Wide Meta-analysis Illuminates Genetic Architecture of Type 2 Diabetes. (ucdenver.edu)
  • Diploid wheat, Triticum monococcum (genome Am), has been utilized previously for the introgression of stem rust resistance genes Sr21, Sr22, and Sr35. (umn.edu)
  • This single cell will undergo cell division and multiply many, many times to form a baby, who will have a genome made up of a mixture of genes inherited from its mother and father. (familyeducation.com)
  • Researchers have identified several MYO7A gene mutations that can cause nonsyndromic hearing loss, which is loss of hearing that is not associated with other signs and symptoms. (medlineplus.gov)
  • Mutations in this gene are thought to cause two forms of nonsyndromic hearing loss: DFNA11 and DFNB2. (medlineplus.gov)
  • Newly diagnosed with Autosomal recessive myosin storage myopathy? (globalgenes.org)
  • In addition to their classic association with CRB1 mutations, other genes are implicated. (lu.se)
  • for instance, carriers of sickle-cell disease and thalassaemia genes may be protected from contracting malaria. (who.int)
  • Limb-girdle muscular dystrophies (LGMDs) are clinically and genetically heterogeneous muscle disorders inherited as an autosomal recessive or dominant pattern. (biomedcentral.com)
  • it is updated every other year to include new disorders or disease-causing genes. (springer.com)
  • Red hair can be considered a recessive trait. (familyeducation.com)
  • Our results suggest that this gene, which accounts for 28% of the variation of the trait, may be involved in the control of basal IgE production, independently of specific response to allergens. (ox.ac.uk)
  • If you have only one copy of the gene, you are said to have sickle cell trait. (healthline.com)
  • People who only inherit a mutated gene (hemoglobin S) from one parent are said to have sickle cell trait. (healthline.com)
  • Of the 49 babies with multiple malformations, 21 (42.8%) had recog- nized syndromes, most of which were autosomal recessive and 17 had chromosomal aberrations. (who.int)
  • The total chromosomal content of a cell involves approximately 105 genes in a specialized macromolecule of deoxyribonucleic acid (DNA). (cdc.gov)
  • Both parents of an affected individual are carriers of the abnormal gene but are clinically healthy. (medscape.com)
  • This gene encodes a member of the tumor necrosis factor (TNF) cytokine family which is a ligand for osteoprotegerin and functions as a key factor for osteoclast differentiation and activation. (nih.gov)
  • However, mutations in the beta subunit of the rod cGMP-phosphodiesterase gene, 8- 11 in the ATP binding cassette receptor gene, 12 in the TULP1 gene, 13 in the alpha subunit of the rod cGMP gated channel, 14 and in the USH2A gene 15 have been detected in a small percentage of Spanish ARRP families. (bmj.com)
  • ASPM (abnormal spindle-like, microcephaly associated) is the most commonly mutated MCPH gene. (nih.gov)
  • Abnormal genes cause polycystic kidney disease, which means that in most cases, the disease runs in families. (mayoclinic.org)
  • Both parents must have abnormal genes to pass on this form of the disease. (mayoclinic.org)
  • The four main types of sickle cell anemia are caused by different mutations in these genes. (healthline.com)
  • Genes that influence the PHENOTYPE only in the homozygous state. (ucdenver.edu)
  • Recent work has shown that mice homozygous for Ahl are not only more sensitive to noise , but also are probably damaged in a different manner by noise than mice containing the wild-type gene. (cdc.gov)
  • All affected persons had homozygous deletion of 12 bp (155-166del) in exon 3 of the TBCE gene. (who.int)
  • This study aimed to identify the pathogenic variant in a consanguineous Pakistani family with autosomal recessive LGMD type 10. (biomedcentral.com)
  • Genetic and mutational heterogeneity of autosomal recessive chronic granulomatous disease in Tunisia. (lu.se)
  • PINK1, a gene associated with Parkinson's disease, is not just responsible for the premature death of dopaminergic neurons, it also plays a key role in the neurogenesis of dopamine neurons throughout life. (neurosciencenews.com)
  • Parkinson's patients carrying mutations in PINK1 and Parkin genes have increased levels of circulating interleukin 6 and mitochondrial DNA. (neurosciencenews.com)
  • Autosomal recessive polycystic kidney disease (ARPKD) is the most common heritable cystic renal disease occurring in infancy and childhood. (medscape.com)
  • One of these mutations is in UBE3B, which is closely related to UBE3A , the gene mutated in Angelman syndrome . (spectrumnews.org)
  • When Do Symptoms of Autosomal recessive multiple pterygium syndrome Begin? (nih.gov)
  • More than 200 mutations in the MYO7A gene have been identified in people with Usher syndrome type I, which is characterized by a combination of hearing loss, vision loss, and problems with balance and coordination. (medlineplus.gov)
  • which means both copies of the gene in each cell have mutations. (medlineplus.gov)
  • Recessive mutations, however, are only harmful when two copies are inherited, each from one carrier parent. (spectrumnews.org)
  • None of 700 controls from the Coriell Cell Repositories in New Jersey carry these mutations in both gene copies. (spectrumnews.org)
  • To have the blue eyes phenotype you must have two copies of the blue recessive allele. (familyeducation.com)
  • You need two copies of the gene to have the disease. (healthline.com)
  • It occurs when you inherit copies of the hemoglobin S gene from both parents. (healthline.com)
  • Multipathotype seedling tests of biparental populations demonstrated that T. monococcum accession PI 306540 collected in Romania contains a recessive resistance gene effective to all P. graminis f. sp. (umn.edu)
  • We will refer to this gene as SrTm4, which is the fourth stem rust resistance gene characterized from T. monococcum. (umn.edu)
  • The KIT gene is rather complex consisting of 21 exons in a 70 kb region. (creation.com)
  • Exons 2 (first coding exon), 3 (second cod- and Kuwait: the incidence in Saudi Ara- ing exon) and 12 of the TBCE gene were bia varies from 1:40 000 to 1:100 000 live chosen for the initial screening as they were births [ 6 ]. (who.int)
  • Diagnosis of autosomal recessive polycystic kidney disease may be difficult, especially without a family history. (msdmanuals.com)