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)
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.
Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.
An individual having different alleles at one or more loci regarding a specific character.
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.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.
A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.
A maternally linked genetic disorder that presents in mid-life as acute or subacute central vision loss leading to central scotoma and blindness. The disease has been associated with missense mutations in the mtDNA, in genes for Complex I, III, and IV polypeptides, that can act autonomously or in association with each other to cause the disease. (from Online Mendelian Inheritance in Man, http://www.ncbi.nlm.nih.gov/Omim/, MIM#535000 (April 17, 2001))
The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
Any detectable and heritable alteration in the lineage of germ cells. Mutations in these cells (i.e., "generative" cells ancestral to the gametes) are transmitted to progeny while those in somatic cells are not.
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.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Biochemical identification of mutational changes in a nucleotide sequence.
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.
A tumor suppressor gene (GENES, TUMOR SUPPRESSOR) located on human CHROMOSOME 17 at locus 17q21. Mutations of this gene are associated with the formation of HEREDITARY BREAST AND OVARIAN CANCER SYNDROME. It encodes a large nuclear protein that is a component of DNA repair pathways.
GENES with ALLELES that affect the PHENOTYPE associated with a nonallelic gene.
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.
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 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.
Congenital MEGACOLON resulting from the absence of ganglion cells (aganglionosis) in a distal segment of the LARGE INTESTINE. The aganglionic segment is permanently contracted thus causing dilatation proximal to it. In most cases, the aganglionic segment is within the RECTUM and SIGMOID COLON.
Any method used for determining the location of and relative distances between genes on a chromosome.
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.
An individual in which both alleles at a given locus are identical.
Genes that influence the PHENOTYPE only in the homozygous state.
An ethnic group with historical ties to the land of ISRAEL and the religion of JUDAISM.
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)
The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.
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 tumor suppressor gene (GENES, TUMOR SUPPRESSOR) located on human chromosome 13 at locus 13q12.3. Mutations in this gene predispose humans to breast and ovarian cancer. It encodes a large, nuclear protein that is an essential component of DNA repair pathways, suppressing the formation of gross chromosomal rearrangements. (from Genes Dev 2000;14(11):1400-6)
A condition characterized by focal DYSTONIA that progresses to involuntary spasmodic contractions of the muscles of the legs, trunk, arms, and face. The hands are often spared, however, sustained axial and limb contractions may lead to a state where the body is grossly contorted. Onset is usually in the first or second decade. Familial patterns of inheritance, primarily autosomal dominant with incomplete penetrance, have been identified. (Adams et al., Principles of Neurology, 6th ed, p1078)
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)
A social group consisting of parents or parent substitutes and children.
A characteristic symptom complex.
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.
Identification of genetic carriers for a given trait.
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 attitude or posture due to the co-contraction of agonists and antagonist muscles in one region of the body. It most often affects the large axial muscles of the trunk and limb girdles. Conditions which feature persistent or recurrent episodes of dystonia as a primary manifestation of disease are referred to as DYSTONIC DISORDERS. (Adams et al., Principles of Neurology, 6th ed, p77)
A large, nuclear protein, encoded by the BRCA2 gene (GENE, BRCA2). Mutations in this gene predispose humans to breast and ovarian cancer. The BRCA2 protein is an essential component of DNA repair pathways, suppressing the formation of gross chromosomal rearrangements. (from Genes Dev. 2000;14(11):1400-6)
Inherited disorders of the peripheral nervous system associated with the deposition of AMYLOID in nerve tissue. The different clinical types based on symptoms correspond to the presence of a variety of mutations in several different proteins including transthyretin (PREALBUMIN); APOLIPOPROTEIN A-I; and GELSOLIN.
An educational process that provides information and advice to individuals or families about a genetic condition that may affect them. The purpose is to help individuals make informed decisions about marriage, reproduction, and other health management issues based on information about the genetic disease, the available diagnostic tests, and management programs. Psychosocial support is usually offered.
Genotypic differences observed among individuals in a population.
A condition with multiple tumor-like lesions caused either by congenital or developmental malformations of BLOOD VESSELS, or reactive vascular proliferations, such as in bacillary angiomatosis. Angiomatosis is considered non-neoplastic.
A disorder of iron metabolism characterized by a triad of HEMOSIDEROSIS; LIVER CIRRHOSIS; and DIABETES MELLITUS. It is caused by massive iron deposits in parenchymal cells that may develop after a prolonged increase of iron absorption. (Jablonski's Dictionary of Syndromes & Eponymic Diseases, 2d ed)
A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.
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.
'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.
Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.
Receptor protein-tyrosine kinases involved in the signaling of GLIAL CELL-LINE DERIVED NEUROTROPHIC FACTOR ligands. They contain an extracellular cadherin domain and form a receptor complexes with GDNF RECEPTORS. Mutations in ret protein are responsible for HIRSCHSPRUNG DISEASE and MULTIPLE ENDOCRINE NEOPLASIA TYPE 2.
Congenital structural deformities, malformations, or other abnormalities of the cranium and facial bones.
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.
A malignant tumor arising from the nuclear layer of the retina that is the most common primary tumor of the eye in children. The tumor tends to occur in early childhood or infancy and may be present at birth. The majority are sporadic, but the condition may be transmitted as an autosomal dominant trait. Histologic features include dense cellularity, small round polygonal cells, and areas of calcification and necrosis. An abnormal pupil reflex (leukokoria); NYSTAGMUS, PATHOLOGIC; STRABISMUS; and visual loss represent common clinical characteristics of this condition. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2104)
A subdiscipline of human genetics which entails the reliable prediction of certain human disorders as a function of the lineage and/or genetic makeup of an individual or of any two parents or potential parents.
A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.
A transfer RNA which is specific for carrying isoleucine to sites on the ribosomes in preparation for protein synthesis.
An autosomal dominant inherited form of HYPERTROPHIC CARDIOMYOPATHY. It results from any of more than 50 mutations involving genes encoding contractile proteins such as VENTRICULAR MYOSINS; cardiac TROPONIN T; ALPHA-TROPOMYOSIN.
A subtype of bone morphogenetic protein receptors with low affinity for BONE MORPHOGENETIC PROTEINS. They are constitutively active PROTEIN-SERINE-THREONINE KINASES that can interact with and phosphorylate TYPE I BONE MORPHOGENETIC PROTEIN RECEPTORS.
A tetrameric protein, molecular weight between 50,000 and 70,000, consisting of 4 equal chains, and migrating on electrophoresis in 3 fractions more mobile than serum albumin. Its concentration ranges from 7 to 33 per cent in the serum, but levels decrease in liver disease.
Involuntary shock-like contractions, irregular in rhythm and amplitude, followed by relaxation, of a muscle or a group of muscles. This condition may be a feature of some CENTRAL NERVOUS SYSTEM DISEASES; (e.g., EPILEPSY, MYOCLONIC). Nocturnal myoclonus is the principal feature of the NOCTURNAL MYOCLONUS SYNDROME. (From Adams et al., Principles of Neurology, 6th ed, pp102-3).
The condition of a pattern of malignancies within a family, but not every individual's necessarily having the same neoplasm. Characteristically the tumor tends to occur at an earlier than average age, individuals may have more than one primary tumor, the tumors may be multicentric, usually more than 25 percent of the individuals in direct lineal descent from the proband are affected, and the cancer predisposition in these families behaves as an autosomal dominant trait with about 60 percent penetrance.
The different ways GENES and their ALLELES interact during the transmission of genetic traits that effect the outcome of GENE EXPRESSION.
Tumors or cancer of the human BREAST.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
Hereditary conditions that feature progressive visual loss in association with optic atrophy. Relatively common forms include autosomal dominant optic atrophy (OPTIC ATROPHY, AUTOSOMAL DOMINANT) and Leber hereditary optic atrophy (OPTIC ATROPHY, HEREDITARY, LEBER).
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.
Acquired and inherited conditions that feature DYSTONIA as a primary manifestation of disease. These disorders are generally divided into generalized dystonias (e.g., dystonia musculorum deformans) and focal dystonias (e.g., writer's cramp). They are also classified by patterns of inheritance and by age of onset.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.
A relatively rare, usually benign neoplasm originating in the chemoreceptor tissue of the CAROTID BODY; GLOMUS JUGULARE; GLOMUS TYMPANICUM; AORTIC BODIES; and the female genital tract. It consists histologically of rounded or ovoid hyperchromatic cells that tend to be grouped in an alveolus-like pattern within a scant to moderate amount of fibrous stroma and a few large thin-walled vascular channels. (From Stedman, 27th ed)
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).
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.
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.
Tumors or cancer of the OVARY. These neoplasms can be benign or malignant. They are classified according to the tissue of origin, such as the surface EPITHELIUM, the stromal endocrine cells, and the totipotent GERM CELLS.
Congenital absence of or defects in structures of the eye; may also be hereditary.

Evidence that mutations in the X-linked DDP gene cause incompletely penetrant and variable skewed X inactivation. (1/637)

X chromosome inactivation results in the random transcriptional silencing of one of the two X chromosomes early in female development. After random inactivation, certain deleterious X-linked mutations can create a selective disadvantage for cells in which the mutation is on the active X chromosome, leading to X inactivation patterns with the mutation on the inactive X chromosome in nearly 100% of the individual's cells. In contrast to the homogeneous patterns of complete skewed inactivation noted for many X-linked disorders, here we describe a family segregating a mutation in the dystonia-deafness peptide (DDP) gene, in which female carriers show incompletely penetrant and variable X inactivation patterns in peripheral blood leukocytes, ranging between 50:50 and >95:5. To address the genetic basis for the unusual pattern of skewing in this family, we first mapped the locus responsible for the variable skewing to the proximal long arm (Xq12-q22) of the X chromosome (Z=5. 7, P=.002, LOD score 3.57), a region that includes both the DDP and the XIST genes. Examination of multiple cell types from women carrying a DDP mutation and of peripheral blood leukocytes from women from two unrelated families who carry different mutations in the DDP gene suggests that the skewed X inactivation is the result of selection against cells containing the mutant DDP gene on the active X chromosome, although skewing is apparently not as severe as that seen for many other deleterious X-linked mutations. Thus, DDP is an example of an X-linked gene for which mutations cause partial cell selection and thus incompletely skewed X inactivation in peripheral blood leukocytes.  (+info)

Evidence for a rare prostate cancer-susceptibility locus at chromosome 1p36. (2/637)

Combining data from a genomic screen in 70 families with a high risk for prostate cancer (PC) with data from candidate-region mapping in these families and an additional 71 families, we have localized a potential hereditary PC-susceptibility locus to chromosome 1p36. Because an excess of cases of primary brain cancer (BC) have been observed in some studies of families with a high risk for PC, and because loss of heterozygosity at 1p36 is frequently observed in BC, we further evaluated 12 families with both a history of PC and a blood relative with primary BC. The overall LOD score in these 12 families was 3.22 at a recombination fraction (theta) of .06, with marker D1S507. On the basis of an a priori hypothesis, this group was stratified by age at diagnosis of PC. In the younger age group (mean age at diagnosis <66 years), a maximum two-point LOD score of 3.65 at straight theta = .0 was observed, with D1S407. This linkage was rejected in both early- and late-onset families without a history of BC (LOD scores -7.12 and -6.03, respectively, at straight theta = .0). After exclusion of 3 of the 12 families that had better evidence of linkage to previously described PC-susceptibility loci, linkage to the 1p36 region was suggested by a two-point LOD score of 4.74 at straight theta = .0, with marker D1S407. We conclude that a significant proportion of these families with both a high risk for PC and a family member with BC show linkage to the 1p36 region.  (+info)

Analysis of affected sib pairs, with covariates--with and without constraints. (3/637)

Covariate models have previously been developed as an extension to affected-sib-pair methods in which the covariate effects are jointly estimated with the degree of excess allele sharing. These models can estimate the differences in sib-pair allele sharing that are associated with measurable environment or genes. When there are no covariates, the pattern of identical-by-descent allele sharing in affected sib pairs is expected to fall within a small triangular region of the potential parameter space, under most genetic models. By restriction of the estimated allele sharing to this triangle, improved power is obtained in tests for genetic linkage. When the affected-sib-pair model is generalized to allow for covariates that affect allele sharing, however, new constraints and new methods for the application of constraints are required. Three generalized constraint methods are proposed and evaluated by use of simulated data. The results compare the power of the different methods, with and without covariates, for a single-gene model with age-dependent onset and for quantitative and qualitative gene-environment and gene-gene interaction models. Covariates can improve the power to detect linkage and can be particularly valuable when there are qualitative gene-environment interactions. In most situations, the best strategy is to assume that there is no dominance variance and to obtain constrained estimates for covariate models under this assumption.  (+info)

Targeted disruption of Smad3 reveals an essential role in transforming growth factor beta-mediated signal transduction. (4/637)

The Smads are a family of nine related proteins which function as signaling intermediates for the transforming growth factor beta (TGF-beta) superfamily of ligands. To discern the in vivo functions of one of these Smads, Smad3, we generated mice harboring a targeted disruption of this gene. Smad3 null mice, although smaller than wild-type littermates, are viable, survive to adulthood, and exhibit an early phenotype of forelimb malformation. To study the cellular functions of Smad3, we generated Smad3 null mouse embryonic fibroblasts (MEFs) and dermal fibroblasts. We demonstrate that null MEFs have lost the ability to form Smad-containing DNA binding complexes and are unable to induce transcription from the TGF-beta-responsive promoter construct, p3TP-lux. Using the primary dermal fibroblasts, we also demonstrate that Smad3 is integral for induction of endogenous plasminogen activator inhibitor 1. We subsequently demonstrate that Smad3 null MEFs are partially resistant to TGF-beta's antiproliferative effect, thus firmly establishing a role for Smad3 in TGF-beta-mediated growth inhibition. We next examined cells in which Smad3 is most highly expressed, specifically cells of immune origin. Although no specific developmental defect was detected in the immune system of the Smad3 null mice, a functional defect was observed in the ability of TGF-beta to inhibit the proliferation of splenocytes activated by specific stimuli. In addition, primary splenocytes display defects in TGF-beta-mediated repression of cytokine production. These data, taken together, establish a role for Smad3 in mediating the antiproliferative effects of TGF-beta and implicate Smad3 as a potential effector for TGF-beta in modulating immune system function.  (+info)

Mutation and haplotype studies of familial Mediterranean fever reveal new ancestral relationships and evidence for a high carrier frequency with reduced penetrance in the Ashkenazi Jewish population. (5/637)

Familial Mediterranean fever (FMF) is a recessive disorder characterized by episodes of fever with serositis or synovitis. The FMF gene (MEFV) was cloned recently, and four missense mutations were identified. Here we present data from non-Ashkenazi Jewish and Arab patients in whom we had not originally found mutations and from a new, more ethnically diverse panel. Among 90 symptomatic mutation-positive individuals, 11 mutations accounted for 79% of carrier chromosomes. Of the two mutations that are novel, one alters the same residue (680) as a previously known mutation, and the other (P369S) is located in exon 3. Consistent with another recent report, the E148Q mutation was observed in patients of several ethnicities and on multiple microsatellite haplotypes, but haplotype data indicate an ancestral relationships between non-Jewish Italian and Ashkenazi Jewish patients with FMF and other affected populations. Among approximately 200 anonymous Ashkenazi Jewish DNA samples, the MEFV carrier frequency was 21%, with E148Q the most common mutation. Several lines of evidence indicate reduced penetrance among Ashkenazi Jews, especially for E148Q, P369S, and K695R. Nevertheless, E148Q helps account for recessive inheritance in an Ashkenazi family previously reported as an unusual case of dominantly inherited FMF. The presence of three frequent MEFV mutations in multiple Mediterranean populations strongly suggests a heterozygote advantage in this geographic region.  (+info)

Autoimmune lymphoproliferative syndrome with defective Fas: genotype influences penetrance. (6/637)

Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of lymphocyte homeostasis and immunological tolerance. Most patients have a heterozygous mutation in the APT1 gene, which encodes Fas (CD95, APO-1), mediator of an apoptotic pathway crucial to lymphocyte homeostasis. Of 17 unique APT1 mutations in unrelated ALPS probands, 12 (71%) occurred in exons 7-9, which encode the intracellular portion of Fas. In vitro, activated lymphocytes from all 17 patients showed apoptotic defects when exposed to an anti-Fas agonist monoclonal antibody. Similar defects were found in a Fas-negative cell line transfected with cDNAs bearing each of the mutations. In cotransfection experiments, Fas constructs with either intra- or extracellular mutations caused dominant inhibition of apoptosis mediated by wild-type Fas. Two missense Fas variants, not restricted to patients with ALPS, were identified. Variant A(-1)T at the Fas signal-sequence cleavage site, which mediates apoptosis less well than wild-type Fas and is partially inhibitory, was present in 13% of African American alleles. Among the ALPS-associated Fas mutants, dominant inhibition of apoptosis was much more pronounced in mutants affecting the intracellular, versus extracellular, portion of the Fas receptor. Mutations causing disruption of the intracellular Fas death domain also showed a higher penetrance of ALPS phenotype features in mutation-bearing relatives. Significant ALPS-related morbidity occurred in 44% of relatives with intracellular mutations, versus 0% of relatives with extracellular mutations. Thus, the location of mutations within APT1 strongly influences the development and the severity of ALPS.  (+info)

Genetic linkage of IgA deficiency to the major histocompatibility complex: evidence for allele segregation distortion, parent-of-origin penetrance differences, and the role of anti-IgA antibodies in disease predisposition. (7/637)

Immunoglobulin A (IgA) deficiency (IgAD) is characterized by a defect of terminal lymphocyte differentiation, leading to a lack of IgA in serum and mucosal secretions. Familial clustering, variable population prevalence in different ethnic groups, and a predominant inheritance pattern suggest a strong genetic predisposition to IgAD. The genetic susceptibility to IgAD is shared with a less prevalent, but more profound, defect called "common variable immunodeficiency" (CVID). Here we show an increased allele sharing at 6p21 in affected members of 83 multiplex IgAD/CVID pedigrees and demonstrate, using transmission/diseqilibrium tests, family-based associations indicating the presence of a predisposing locus, designated "IGAD1," in the proximal part of the major histocompatibility complex (MHC). The recurrence risk of IgAD was found to depend on the sex of parents transmitting the defect: affected mothers were more likely to produce offspring with IgAD than were affected fathers. Carrier mothers but not carrier fathers transmitted IGAD1 alleles more frequently to the affected offspring than would be expected under random segregation. The differential parent-of-origin penetrance is proposed to reflect a maternal effect mediated by the production of anti-IgA antibodies tentatively linked to IGAD1. This is supported by higher frequency of anti-IgA-positive females transmitting the disorder to children, in comparison with female IgAD nontransmitters, and by linkage data in the former group. Such pathogenic mechanisms may be shared by other MHC-linked complex traits associated with the production of specific autoantibodies, parental effects, and a particular MHC haplotype.  (+info)

Linkage of type 2 diabetes mellitus and of age at onset to a genetic location on chromosome 10q in Mexican Americans. (8/637)

Since little is known about chromosomal locations harboring type 2 diabetes-susceptibility genes, we conducted a genomewide scan for such genes in a Mexican American population. We used data from 27 low-income extended Mexican American pedigrees consisting of 440 individuals for whom genotypic data are available for 379 markers. We used a variance-components technique to conduct multipoint linkage analyses for two phenotypes: type 2 diabetes (a discrete trait) and age at onset of diabetes (a truncated quantitative trait). For the multipoint analyses, a subset of 295 markers was selected on the basis of optimal spacing and informativeness. We found significant evidence that a susceptibility locus near the marker D10S587 on chromosome 10q influences age at onset of diabetes (LOD score 3.75) and is also linked with type 2 diabetes itself (LOD score 2.88). This susceptibility locus explains 63.8%+/-9.9% (P=. 000016) of the total phenotypic variation in age at onset of diabetes and 65.7%+/-10.9% (P=.000135) of the total variation in liability to type 2 diabetes. Weaker evidence was found for linkage of diabetes and of age at onset to regions on chromosomes 3p, 4q, and 9p. In conclusion, our strongest evidence for linkage to both age at onset of diabetes and type 2 diabetes itself in the Mexican American population was for a region on chromosome 10q.  (+info)

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.

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.

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).

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.

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 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.

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.

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.

Hereditary Optic Atrophy, Leber type (LOA) is a mitochondrial DNA-associated inherited condition that primarily affects the optic nerve and leads to vision loss. It is characterized by the degeneration of retinal ganglion cells and their axons, which make up the optic nerve. This results in bilateral, painless, and progressive visual deterioration, typically beginning in young adulthood (14-35 years).

Leber's hereditary optic atrophy is caused by mutations in the mitochondrial DNA (mtDNA) gene MT-ND4 or MT-ND6. The condition follows a maternal pattern of inheritance, meaning that it is passed down through the mother's lineage.

The onset of LOA usually occurs in one eye first, followed by the second eye within weeks to months. Central vision is initially affected, leading to blurriness and loss of visual acuity. Color vision may also be impaired. The progression of the condition generally stabilizes after a few months, but complete recovery of vision is unlikely.

Currently, there is no cure for Leber's hereditary optic atrophy. Treatment focuses on managing symptoms and providing visual rehabilitation to help affected individuals adapt to their visual impairment.

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.

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.

A germ-line mutation is a genetic change that occurs in the egg or sperm cells (gametes), and thus can be passed down from parents to their offspring. These mutations are present throughout the entire body of the offspring, as they are incorporated into the DNA of every cell during embryonic development.

Germ-line mutations differ from somatic mutations, which occur in other cells of the body that are not involved in reproduction. While somatic mutations can contribute to the development of cancer and other diseases within an individual, they are not passed down to future generations.

It's important to note that germ-line mutations can have significant implications for medical genetics and inherited diseases. For example, if a parent has a germ-line mutation in a gene associated with a particular disease, their offspring may have an increased risk of developing that disease as well.

"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.

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.

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.

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.

BRCA1 (BReast CAncer gene 1) is a tumor suppressor gene that produces a protein involved in repairing damaged DNA and maintaining genetic stability. Mutations in the BRCA1 gene are associated with an increased risk of developing hereditary breast and ovarian cancers. Inherited mutations in this gene account for about 5% of all breast cancers and about 10-15% of ovarian cancers. Women who have a mutation in the BRCA1 gene have a significantly higher risk of developing breast cancer and ovarian cancer compared to women without mutations. The protein produced by the BRCA1 gene also interacts with other proteins to regulate cell growth and division, so its disruption can lead to uncontrolled cell growth and tumor formation.

A genetic modifier refers to a gene that influences the expression or penetrance of another gene. In other words, it is a gene that can change the way that a particular genetic trait is expressed. Genetic modifiers do not cause the trait itself, but rather modify its appearance or severity. They can either increase (enhancer) or decrease (suppressor) the effect of the primary gene in question. Modifier genes can help explain why two individuals with the same genetic mutation may have different symptoms or severity of a particular genetic condition.

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.

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.

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.

Hirschsprung disease is a gastrointestinal disorder that affects the large intestine, specifically the section known as the colon. This condition is congenital, meaning it is present at birth. It occurs due to the absence of ganglion cells (nerve cells) in the bowel's muscular wall, which are responsible for coordinating muscle contractions that move food through the digestive tract.

The affected segment of the colon cannot relax and propel the contents within it, leading to various symptoms such as constipation, intestinal obstruction, or even bowel perforation in severe cases. Common diagnostic methods include rectal suction biopsy, anorectal manometry, and contrast enema studies. Treatment typically involves surgical removal of the aganglionic segment and reattachment of the normal colon to the anus (known as a pull-through procedure).

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.

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.

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.

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.

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!

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.

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.

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.

BRCA2 is a specific gene that provides instructions for making a protein that helps suppress the growth of cells and plays a crucial role in repairing damaged DNA. Mutations in the BRCA2 gene are known to significantly increase the risk of developing breast cancer, ovarian cancer, and several other types of cancer.

The BRCA2 protein is involved in the process of homologous recombination, which is a type of DNA repair that occurs during cell division. When DNA is damaged, this protein helps to fix the damage by finding a similar sequence on a sister chromatid (a copy of the chromosome) and using it as a template to accurately repair the break.

If the BRCA2 gene is mutated and cannot produce a functional protein, then the cell may not be able to repair damaged DNA effectively. Over time, this can lead to an increased risk of developing cancer due to the accumulation of genetic alterations that cause cells to grow and divide uncontrollably.

It's worth noting that while mutations in the BRCA2 gene are associated with an increased risk of cancer, not everyone who has a mutation will develop cancer. However, those who do develop cancer tend to have an earlier onset and more aggressive form of the disease. Genetic testing can be used to identify mutations in the BRCA2 gene, which can help inform medical management and screening recommendations for individuals and their families.

'Dystonia Musculorum Deformans' is a medical term that refers to a rare inherited neurological disorder, which is now more commonly known as "Generalized Dystonia." This condition is characterized by sustained muscle contractions, leading to twisting and repetitive movements or abnormal postures.

The onset of symptoms typically occurs during childhood or adolescence, and they can progress over time, affecting various parts of the body. The exact cause of Generalized Dystonia is not fully understood, but it is believed to involve genetic mutations that affect the functioning of certain proteins in the brain. Treatment options may include medications, botulinum toxin injections, or even deep brain stimulation surgery in severe cases.

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.

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.

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.

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.

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 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.

Dystonia is a neurological movement disorder characterized by involuntary muscle contractions, leading to repetitive or twisting movements. These movements can be painful and may affect one part of the body (focal dystonia) or multiple parts (generalized dystonia). The exact cause of dystonia varies, with some cases being inherited and others resulting from damage to the brain. Treatment options include medications, botulinum toxin injections, and deep brain stimulation surgery.

BRCA2 (pronounced "braca two") protein is a tumor suppressor protein that plays a crucial role in repairing damaged DNA in cells. It is encoded by the BRCA2 gene, which is located on chromosome 13. Mutations in the BRCA2 gene have been associated with an increased risk of developing certain types of cancer, particularly breast and ovarian cancer in women, and breast and prostate cancer in men.

The BRCA2 protein interacts with other proteins to repair double-strand breaks in DNA through a process called homologous recombination. When the BRCA2 protein is not functioning properly due to a mutation, damaged DNA may not be repaired correctly, leading to genetic instability and an increased risk of cancer.

It's important to note that not all people with BRCA2 mutations will develop cancer, but their risk is higher than those without the mutation. Genetic testing can identify individuals who have inherited a mutation in the BRCA2 gene and help guide medical management and screening recommendations.

Familial amyloid neuropathies are a group of inherited disorders characterized by the accumulation of abnormal deposits of amyloid proteins in various tissues and organs of the body. These abnormal deposits can cause damage to nerves, leading to a peripheral neuropathy that affects sensation, movement, and organ function.

There are several types of familial amyloid neuropathies, each caused by different genetic mutations. The most common type is known as transthyretin-related hereditary amyloidosis (TTR-HA), which is caused by mutations in the TTR gene. Other types include apolipoprotein A1-related hereditary amyloidosis (APOA1-HA) and gelsolin-related amyloidosis (AGel-HA).

Symptoms of familial amyloid neuropathies can vary depending on the type and severity of the disorder. Common symptoms include:

* Numbness, tingling, or pain in the hands and feet
* Weakness or loss of muscle strength in the legs and arms
* Autonomic nervous system dysfunction, leading to problems with digestion, heart rate, blood pressure, and temperature regulation
* Carpal tunnel syndrome
* Eye abnormalities, such as vitreous opacities or retinal deposits
* Kidney disease

Familial amyloid neuropathies are typically inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the mutated gene from an affected parent. Diagnosis is usually made through genetic testing and confirmation of the presence of amyloid deposits in tissue samples.

Treatment for familial amyloid neuropathies typically involves managing symptoms and slowing the progression of the disease. This may include medications to control pain, physical therapy to maintain muscle strength and mobility, and devices such as braces or wheelchairs to assist with mobility. In some cases, liver transplantation may be recommended to remove the source of the mutated transthyretin protein.

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.

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.

Angiomatosis is a medical term that refers to a benign condition characterized by the proliferation of blood vessels in various tissues and organs. It is typically composed of small, tangled blood vessels called capillaries, which can form clusters or networks. The condition can affect skin, internal organs, bones, and other tissues.

Angiomatosis is often asymptomatic and may be discovered incidentally during medical imaging or surgical procedures. In some cases, it may cause symptoms such as pain, swelling, or bleeding, depending on the location and extent of the lesions.

While angiomatosis is generally a benign condition, in rare cases, it can be associated with malignant tumors or other medical conditions. Treatment options for angiomatosis depend on the size, location, and symptoms of the lesions and may include observation, medication, or surgical removal.

Hemochromatosis is a medical condition characterized by excessive absorption and accumulation of iron in the body, resulting in damage to various organs. It's often referred to as "iron overload" disorder. There are two main types: primary (hereditary) and secondary (acquired). Primary hemochromatosis is caused by genetic mutations that lead to increased intestinal iron absorption, while secondary hemochromatosis can be the result of various conditions such as multiple blood transfusions, chronic liver disease, or certain types of anemia.

In both cases, the excess iron gets stored in body tissues, particularly in the liver, heart, and pancreas, which can cause organ damage and lead to complications like cirrhosis, liver failure, diabetes, heart problems, and skin discoloration. Early diagnosis and treatment through regular phlebotomy (blood removal) or chelation therapy can help manage the condition and prevent severe complications.

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.

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.

'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.

"Likelihood functions" is a statistical concept that is used in medical research and other fields to estimate the probability of obtaining a given set of data, given a set of assumptions or parameters. In other words, it is a function that describes how likely it is to observe a particular outcome or result, based on a set of model parameters.

More formally, if we have a statistical model that depends on a set of parameters θ, and we observe some data x, then the likelihood function is defined as:

L(θ | x) = P(x | θ)

This means that the likelihood function describes the probability of observing the data x, given a particular value of the parameter vector θ. By convention, the likelihood function is often expressed as a function of the parameters, rather than the data, so we might instead write:

L(θ) = P(x | θ)

The likelihood function can be used to estimate the values of the model parameters that are most consistent with the observed data. This is typically done by finding the value of θ that maximizes the likelihood function, which is known as the maximum likelihood estimator (MLE). The MLE has many desirable statistical properties, including consistency, efficiency, and asymptotic normality.

In medical research, likelihood functions are often used in the context of Bayesian analysis, where they are combined with prior distributions over the model parameters to obtain posterior distributions that reflect both the observed data and prior knowledge or assumptions about the parameter values. This approach is particularly useful when there is uncertainty or ambiguity about the true value of the parameters, as it allows researchers to incorporate this uncertainty into their analyses in a principled way.

Proto-oncogene proteins c-RET are a group of gene products that play crucial roles in the development and functioning of the nervous system, as well as in other tissues. The c-RET proto-oncogene encodes a receptor tyrosine kinase, which is a type of enzyme that helps transmit signals from the outside to the inside of cells. This receptor is activated by binding to its ligands, leading to the activation of various signaling pathways that regulate cell growth, differentiation, and survival.

Mutations in the c-RET proto-oncogene can lead to its overactivation, resulting in the conversion of this gene into an oncogene. Oncogenes are genes that have the potential to cause cancer when they are mutated or abnormally expressed. Activating mutations in c-RET have been implicated in several types of human cancers, including multiple endocrine neoplasia type 2 (MEN2), papillary thyroid carcinoma, and certain types of lung and kidney cancers. These mutations can lead to the constitutive activation of c-RET, resulting in uncontrolled cell growth and tumor formation.

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.

Mitochondrial DNA (mtDNA) is the genetic material present in the mitochondria, which are specialized structures within cells that generate energy. Unlike nuclear DNA, which is present in the cell nucleus and inherited from both parents, mtDNA is inherited solely from the mother.

MtDNA is a circular molecule that contains 37 genes, including 13 genes that encode for proteins involved in oxidative phosphorylation, a process that generates energy in the form of ATP. The remaining genes encode for rRNAs and tRNAs, which are necessary for protein synthesis within the mitochondria.

Mutations in mtDNA can lead to a variety of genetic disorders, including mitochondrial diseases, which can affect any organ system in the body. These mutations can also be used in forensic science to identify individuals and establish biological relationships.

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.

Retinoblastoma is a rare type of eye cancer that primarily affects young children, typically developing in the retina (the light-sensitive tissue at the back of the eye) before the age of 5. This malignancy originates from immature retinal cells called retinoblasts and can occur in one or both eyes (bilateral or unilateral).

There are two main types of Retinoblastoma: heritable and non-heritable. The heritable form is caused by a genetic mutation that can be inherited from a parent or may occur spontaneously during embryonic development. This type often affects both eyes and has an increased risk of developing other cancers. Non-heritable Retinoblastoma, on the other hand, occurs due to somatic mutations (acquired during life) that affect only the retinal cells in one eye.

Symptoms of Retinoblastoma may include a white pupil or glow in photographs, crossed eyes, strabismus (misalignment of the eyes), poor vision, redness, or swelling in the eye. Treatment options depend on various factors such as the stage and location of the tumor(s), patient's age, and overall health. These treatments may include chemotherapy, radiation therapy, laser therapy, cryotherapy (freezing), thermotherapy (heating), or enucleation (removal of the affected eye) in advanced cases.

Early detection and prompt treatment are crucial for improving the prognosis and preserving vision in children with Retinoblastoma. Regular eye examinations by a pediatric ophthalmologist or oncologist are recommended to monitor any changes and ensure timely intervention if necessary.

Medical genetics is the branch of medicine that involves the study of inherited conditions and diseases, as well as the way they are passed down through families. It combines elements of clinical evaluation, laboratory testing, and genetic counseling to help diagnose, manage, and prevent genetic disorders. Medical genetics also includes the study of genetic variation and its role in contributing to both rare and common diseases. Additionally, it encompasses the use of genetic information for pharmacological decision making (pharmacogenomics) and reproductive decision making (preimplantation genetic diagnosis, prenatal testing).

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.

Transfer RNA (tRNA) that carries the amino acid isoleucine is referred to as 'tRNA-Ile' in medical and molecular biology terminology.

tRNAs are specialized RNA molecules that play a crucial role in protein synthesis, by transporting specific amino acids from the cytoplasm to the ribosomes, where proteins are assembled. Each tRNA has an anticodon region that recognizes and binds to a complementary codon sequence on messenger RNA (mRNA). When a tRNA with the correct anticodon pairs with an mRNA codon during translation, the attached amino acid is added to the growing polypeptide chain.

Ile, or isoleucine, is a genetically encoded, hydrophobic amino acid that is one of the 20 standard amino acids found in proteins. Isoleucine is transported by its specific tRNA-Ile molecule during protein synthesis.

Hypertrophic Cardiomyopathy, Familial is a genetic disorder characterized by thickening of the heart muscle (myocardium), specifically the ventricles. This thickening, or hypertrophy, can make it harder for the heart to pump blood effectively, potentially leading to symptoms such as shortness of breath, chest pain, and arrhythmias.

In familial hypertrophic cardiomyopathy, the disorder is inherited and passed down through families in an autosomal dominant pattern, meaning that a child has a 50% chance of inheriting the gene mutation from an affected parent. The condition can vary in severity even within the same family, and some individuals with the genetic mutation may not develop symptoms at all.

It is important to note that while hypertrophic cardiomyopathy can have serious consequences, many people with the condition lead normal lives with appropriate medical management and monitoring.

Bone morphogenetic protein receptors, type II (BMPR2) are a type of cell surface receptor that bind to bone morphogenetic proteins (BMPs), which are growth factors involved in the regulation of various cellular processes such as cell proliferation, differentiation, and apoptosis. BMPR2 is a serine/threonine kinase receptor and forms a complex with type I BMP receptors upon BMP binding. This complex activation leads to the phosphorylation and activation of downstream signaling molecules, including SMAD proteins, which ultimately regulate gene transcription.

Mutations in the BMPR2 gene have been associated with several genetic disorders, most notably pulmonary arterial hypertension (PAH), a rare but life-threatening condition characterized by increased pressure in the pulmonary arteries that supply blood to the lungs. In addition, BMPR2 mutations have also been linked to Marfan syndrome, a genetic disorder that affects connective tissue and can cause skeletal, cardiovascular, and ocular abnormalities.

Prealbumin, also known as transthyretin, is a protein produced primarily in the liver and circulates in the blood. It plays a role in transporting thyroid hormones and vitamin A throughout the body. Prealbumin levels are often used as an indicator of nutritional status and liver function. Low prealbumin levels may suggest malnutrition or inflammation, while increased levels can be seen in certain conditions like hyperthyroidism. It is important to note that prealbumin levels should be interpreted in conjunction with other clinical findings and laboratory tests for a more accurate assessment of a patient's health status.

Myoclonus is a medical term that describes a quick, involuntary jerking muscle spasm. These spasms can happen once or repeat in a series, and they can range from mild to severe in nature. Myoclonus can affect any muscle in the body and can be caused by several different conditions, including certain neurological disorders, injuries, or diseases. In some cases, myoclonus may occur without an identifiable cause.

There are various types of myoclonus, classified based on their underlying causes, patterns of occurrence, and associated symptoms. Some common forms include:

1. Action myoclonus: Occurs during voluntary muscle movements
2. Stimulus-sensitive myoclonus: Triggered by external or internal stimuli, such as touch, sound, or light
3. Physiological myoclonus: Normal muscle jerks that occur during sleep onset (hypnic jerks) or during sleep (nocturnal myoclonus)
4. Reflex myoclonus: Result of a reflex arc activation due to a peripheral nerve stimulation
5. Epileptic myoclonus: Part of an epilepsy syndrome, often involving the brainstem or cortex
6. Symptomatic myoclonus: Occurs as a result of an underlying medical condition, such as metabolic disorders, infections, or neurodegenerative diseases

Treatment for myoclonus depends on the specific type and underlying cause. Medications, physical therapy, or lifestyle modifications may be recommended to help manage symptoms and improve quality of life.

Hereditary neoplastic syndromes refer to genetic disorders that predispose affected individuals to develop tumors or cancers. These syndromes are caused by inherited mutations in specific genes that regulate cell growth and division. As a result, cells may divide and grow uncontrollably, leading to the formation of benign or malignant tumors.

Examples of hereditary neoplastic syndromes include:

1. Hereditary breast and ovarian cancer syndrome (HBOC): This syndrome is caused by mutations in the BRCA1 or BRCA2 genes, which increase the risk of developing breast, ovarian, and other cancers.
2. Lynch syndrome: Also known as hereditary non-polyposis colorectal cancer (HNPCC), this syndrome is caused by mutations in DNA mismatch repair genes, leading to an increased risk of colon, endometrial, and other cancers.
3. Li-Fraumeni syndrome: This syndrome is caused by mutations in the TP53 gene, which increases the risk of developing a wide range of cancers, including breast, brain, and soft tissue sarcomas.
4. Familial adenomatous polyposis (FAP): This syndrome is caused by mutations in the APC gene, leading to the development of numerous colon polyps that can become cancerous if not removed.
5. Neurofibromatosis type 1 (NF1): This syndrome is caused by mutations in the NF1 gene and is characterized by the development of benign tumors called neurofibromas on the nerves and skin.
6. Von Hippel-Lindau disease (VHL): This syndrome is caused by mutations in the VHL gene, leading to an increased risk of developing various types of tumors, including kidney, pancreas, and adrenal gland tumors.

Individuals with hereditary neoplastic syndromes often have a higher risk of developing cancer than the general population, and they may require more frequent screening and surveillance to detect cancers at an early stage when they are more treatable.

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.

Breast neoplasms refer to abnormal growths in the breast tissue that can be benign or malignant. Benign breast neoplasms are non-cancerous tumors or growths, while malignant breast neoplasms are cancerous tumors that can invade surrounding tissues and spread to other parts of the body.

Breast neoplasms can arise from different types of cells in the breast, including milk ducts, milk sacs (lobules), or connective tissue. The most common type of breast cancer is ductal carcinoma, which starts in the milk ducts and can spread to other parts of the breast and nearby structures.

Breast neoplasms are usually detected through screening methods such as mammography, ultrasound, or MRI, or through self-examination or clinical examination. Treatment options for breast neoplasms depend on several factors, including the type and stage of the tumor, the patient's age and overall health, and personal preferences. Treatment may include surgery, radiation therapy, chemotherapy, hormone therapy, or targeted therapy.

Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.

The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.

Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.

Hereditary optic atrophies (HOAs) are a group of genetic disorders that cause degeneration of the optic nerve, leading to vision loss. The optic nerve is responsible for transmitting visual information from the eye to the brain. In HOAs, this nerve degenerates over time, resulting in decreased visual acuity, color vision deficits, and sometimes visual field defects.

There are several types of HOAs, including dominant optic atrophy (DOA), Leber hereditary optic neuropathy (LHON), autosomal recessive optic atrophy (AROA), and Wolfram syndrome. Each type has a different inheritance pattern and is caused by mutations in different genes.

DOA is the most common form of HOA and is characterized by progressive vision loss that typically begins in childhood or early adulthood. It is inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the disease-causing mutation from an affected parent.

LHON is a mitochondrial disorder that primarily affects males and is characterized by sudden, severe vision loss that typically occurs in young adulthood. It is caused by mutations in the mitochondrial DNA and is inherited maternally.

AROA is a rare form of HOA that is inherited in an autosomal recessive manner, meaning that both copies of the gene must be mutated to cause the disease. It typically presents in infancy or early childhood with progressive vision loss.

Wolfram syndrome is a rare genetic disorder that affects multiple organs, including the eyes, ears, and endocrine system. It is characterized by diabetes insipidus, diabetes mellitus, optic atrophy, and hearing loss. It is inherited in an autosomal recessive manner.

There is currently no cure for HOAs, but treatments such as low-vision aids and rehabilitation may help to manage the symptoms. Research is ongoing to develop new therapies for these disorders.

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.

Dystonic disorders are a group of neurological conditions characterized by sustained or intermittent muscle contractions that result in involuntary, repetitive, and often twisting movements and abnormal postures. These movements can affect any part of the body, including the face, neck, limbs, and trunk. Dystonic disorders can be primary, meaning they are caused by genetic mutations or idiopathic causes, or secondary, resulting from brain injury, infection, or other underlying medical conditions.

The most common form of dystonia is cervical dystonia (spasmodic torticollis), which affects the muscles of the neck and results in abnormal head positioning. Other forms of dystonia include blepharospasm (involuntary eyelid spasms), oromandibular dystonia (affecting the muscles of the jaw, face, and tongue), and generalized dystonia (affecting multiple parts of the body).

Dystonic disorders can significantly impact a person's quality of life, causing pain, discomfort, and social isolation. Treatment options include oral medications, botulinum toxin injections, and deep brain stimulation surgery in severe cases.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

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.

Paraganglioma, extra-adrenal, is a type of rare tumor that develops in the nervous system's paraganglia, which are groups of specialized cells that are responsible for regulating blood pressure and other bodily functions. Unlike adrenal paragangliomas, which form in the adrenal glands located on top of the kidneys, extra-adrenal paragangliomas develop outside of the adrenal glands, in various locations along the sympathetic and parasympathetic nervous systems. These tumors can be functional or nonfunctional, meaning they may or may not produce hormones such as catecholamines (epinephrine, norepinephrine, and dopamine). Functional extra-adrenal paragangliomas can cause symptoms related to excessive hormone production, including hypertension, sweating, headaches, and rapid heartbeat. Treatment typically involves surgical removal of the tumor, along with preoperative preparation to manage potential hormonal imbalances.

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.

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 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.

Ovarian neoplasms refer to abnormal growths or tumors in the ovary, which can be benign (non-cancerous) or malignant (cancerous). These growths can originate from various cell types within the ovary, including epithelial cells, germ cells, and stromal cells. Ovarian neoplasms are often classified based on their cell type of origin, histological features, and potential for invasive or metastatic behavior.

Epithelial ovarian neoplasms are the most common type and can be further categorized into several subtypes, such as serous, mucinous, endometrioid, clear cell, and Brenner tumors. Some of these epithelial tumors have a higher risk of becoming malignant and spreading to other parts of the body.

Germ cell ovarian neoplasms arise from the cells that give rise to eggs (oocytes) and can include teratomas, dysgerminomas, yolk sac tumors, and embryonal carcinomas. Stromal ovarian neoplasms develop from the connective tissue cells supporting the ovary and can include granulosa cell tumors, thecomas, and fibromas.

It is essential to diagnose and treat ovarian neoplasms promptly, as some malignant forms can be aggressive and potentially life-threatening if not managed appropriately. Regular gynecological exams, imaging studies, and tumor marker tests are often used for early detection and monitoring of ovarian neoplasms. Treatment options may include surgery, chemotherapy, or radiation therapy, depending on the type, stage, and patient's overall health condition.

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.

The penetrance of the condition is therefore 80%. High and low penetrance: If an allele is highly penetrant, then the trait it ... The penetrance is 100%. Common examples used to show degrees of penetrance are often highly penetrant. There are several ... An allele with low penetrance will only occasionally produce the trait with which it is associated. In cases of low penetrance ... In one study the age-related penetrance of MEN1 was 7% by age 10 but nearly 100% by age 60. Environmental modifiers: Penetrance ...
... both the genotype and phenotype may be said to show incomplete penetrance. Penetrance quantifies the probability that an allele ... Compare penetrance. extant Currently living or existing; still in existence and not extinct. The term is generally used to ... peak shift model pedigree chart penetrance The proportion of individuals with a given genotype who express the associated ...
Penetrance is 100%. Mild to severe intellectual or developmental disability is present in the majority of patients. Epilepsy is ...
2000). "Penetrance and expressivity". An Introduction to Genetic Analysi (7th ed.). New York: W. H. Freeman. ISBN 978-0-7167- ... it differs from penetrance, which refers to the proportion of individuals with a particular genotype that actually express the ... penetrance and expressivity". Nature Education. 1 (1): 137. Marian AJ, Roberts R (April 2001). "The molecular genetic basis for ...
Penetrance differs between populations. Disease-causing genetic variants of the HFE gene account for 90% of the cases of non- ... Considerable debate exists regarding the penetrance-the probability of clinical expression of the trait given the genotype- for ... towards an understanding of the molecular basis of reduced penetrance in human inherited disease". Hum Genet. 132 (10): 1077- ...
"14.2: Penetrance and Expressivity". Biology LibreTexts. 2021-01-13. Retrieved 2021-11-19. "Phenotype Variability: Penetrance ... Penetrance can also be age-dependent, meaning signs or symptoms of disease are not visible until later in life. For example, ... Penetrance is the proportion of individuals showing a specified genotype in their phenotype under a given set of environmental ... Some diseases show incomplete penetrance, meaning not all individuals with the disease-causing allele develop signs or symptoms ...
BHD has very high penetrance. A correlation between different FLCN genotypes and phenotypes has not been discovered. FLCN ...
One explanation for the pattern is that the trait has incomplete penetrance. That is, not every individual with the genes can ... Praxedes LA, Otto PA (December 2000). "Estimation of penetrance from twin data". Twin Research. 3 (4): 294-298. doi:10.1375/ ...
Genetic counseling should be offered to affected and at-risk individuals; for most subtypes, penetrance is incomplete.[citation ...
It is associated with variable expressivity; complete penetrance has been definitively documented. Marfan syndrome is caused by ...
August 2009). "Cerebellothalamocortical connectivity regulates penetrance in dystonia". J. Neurosci. 29 (31): 9740-7. doi: ...
... has full penetrance but variable expressivity; individuals who possess an allele for polysyndactyly may have a ...
ISBN 978-1-59102-776-8. Chen, S.; Parmigiani, G. (April 2007). "Meta-analysis of BRCA1 and BRCA2 penetrance". J Clin Oncol. 25 ... These may be reported as "no mutation". Deleterious mutations have high, but not complete, genetic penetrance, which means that ...
PPAP is an autosomal dominant syndrome caused by germline mutations in DNA polymerase ε (POLE) and δ (POLD1). The penetrance of ...
Transmission is autosomal dominant with incomplete penetrance. Individuals with this condition usually have palmoplantar ...
Chen S, Parmigiani G (April 2007). "Meta-analysis of BRCA1 and BRCA2 penetrance". Journal of Clinical Oncology. 25 (11): 1329- ...
... exhibits reduced penetrance, i.e. only some family members with the mutated gene develop symptoms. The ... and a much lower rate of penetrance. Hypodysfibrinogenemia causes episodes of pathological bleeding and thrombosis due not only ...
Penetrance for this disorder is estimated at 60%. Individuals with GEFS+ present with a range of epilepsy phenotypes. These ...
However, 36 or more residues produce an erroneous mutant form of Htt, (mHtt). Reduced penetrance is found in counts 36-39. ...
This condition is described to have incomplete penetrance of disease. Penetrance is said to be incomplete when some individuals ... The penetrance is estimated to be about 60%. The clinical symptoms are caused by abnormalities of the immune system. Most ...
The allele has variable expressivity, but complete penetrance. Most cases are caused by spontaneous mutation in the gametes; ...
The Pd gene (dominant with incomplete penetrance) causes the benign, pre-axial form of polydactyly where one or more extra toes ... M Manx tailless gene (dominant with high penetrance). Cats with the homozygous genotype (MM) die before birth, and stillborn ... dominant with incomplete penetrance). Cats with this gene have ears that curl forward. There are different degrees of folding, ...
This disease is shown to have reduced penetrance. Thus, some people with pathogenic variants of the TFR2 gene may never present ...
Partial penetrance can be shown and calculated from pedigrees. Penetrance is the percentage expressed frequency with which ...
... 's inheritance is autosomal dominant with variable penetrance. The defect is typically located on the ...
The 96% penetrance figure comes from only one study. Other studies have observed both incomplete and variable penetrance but ... HME has a 96% penetrance, which means that if the affected gene is indeed transmitted to a child, the child will have a 96% of ... Legeai-Mallet L, Munnich A, Maroteaux P, Le Merrer M (July 1997). "Incomplete penetrance and expressivity skewing in hereditary ... leading to speculation that incomplete penetrance is more likely to be exhibited in females. Indeed, other work has shown that ...
... penetrance differs between the types (from 40% to 90%). By definition, the forms of MODY are autosomal dominant, requiring only ...
Inheritance appears to be autosomal dominant with variable penetrance.[citation needed] It appears that two copies of this gene ...
August 2017). "SDHB-related pheochromocytoma and paraganglioma penetrance and genotype-phenotype correlations". Journal of ...
These loci are all autosomal dominantly inherited with reduced penetrance. Although these loci have been found, it is still not ...
The penetrance of the condition is therefore 80%. High and low penetrance: If an allele is highly penetrant, then the trait it ... The penetrance is 100%. Common examples used to show degrees of penetrance are often highly penetrant. There are several ... An allele with low penetrance will only occasionally produce the trait with which it is associated. In cases of low penetrance ... In one study the age-related penetrance of MEN1 was 7% by age 10 but nearly 100% by age 60. Environmental modifiers: Penetrance ...
Reduced penetrance and variable expressivity are factors that impact the effects of particular genetic changes. Learn more ... Reduced penetrance. Penetrance refers to the proportion of people with a particular genetic variant (or gene mutation) who ... For more information about reduced penetrance and variable expressivity:. Additional information about penetrance and ... penetrance. Reduced penetrance often occurs with familial cancer syndromes. For example, many people with a variant in the ...
Low "penetrance" of phylogenetic knowledge in mitochondrial disease studies Biochem Biophys Res Commun. 2005 Jul 22;333(1):122- ...
The Mammalian Phenotype (MP) Ontology is a community effort to provide standard terms for annotating phenotypic data. You can use this browser to view terms, definitions, and term relationships in a hierarchical display. Links to summary annotated phenotype data at MGI are provided in Term Detail reports.
By providing the penetrance, additional, critical information can be given to prospective parents in the genetic counseling ... Estimates of penetrance for recurrent pathogenic copy-number variations Genet Med. 2013 Jun;15(6):478-81. doi: 10.1038/gim. ... By providing the penetrance, additional, critical information can be given to prospective parents in the genetic counseling ... We sought to provide empiric estimates for penetrance for some of these recurrent, disease-susceptibility loci. ...
Low-Penetrance Genotypes and Gene-Environment Interactions ... Low-Penetrance Genotypes and Gene-Environment Interactions. Jun ...
... 2.24 Penetrance is the term used to describe the degree of likelihood (based on clinical ... the penetrance is high-about 99%. For other alleles, the penetrance is lower-but this calculation is also dependent upon the ... The importance of penetrance. *Essentially Yours: The Protection of Human Genetic Information in Australia (ALRC Report 96) ... 2.26 HD is an example of a condition with a very high penetrance, approaching 100%. Those who test positive for the HD mutation ...
Brought to you by Merck & Co, Inc., Rahway, NJ, USA (known as MSD outside the US and Canada)-dedicated to using leading-edge science to save and improve lives around the world. Learn more about the MSD Manuals and our commitment to Global Medical Knowledge.. ...
Our findings of increased penetrance (higher percentage of AMCs) among N/N homozygotes, as well as lower 2-OHE/16α-OHE1 ratios ... Female BMPR2 mutation carriers with the N/N genotype for CYP1B1 N453S have greater penetrance of FPAH, consistent with prior ... Among females, there was four-fold higher penetrance among subjects homozygous for the wild-type genotype (N/N) than those with ... To test this, we studied the relationship between the CYP1B1 Asn453Ser (N453S) genetic polymorphism and FPAH penetrance in ...
... moderate-penetrance genes) as in those with variants in BRCA1, BRCA2, or PALB2 (high-penetrance genes). ... The objective of this study was to evaluate differences in surgical treatment across high- and moderate-penetrance breast ... Prophylactic Bilateral Mastectomy Among Women With Breast Cancer and Pathogenic Variants in High-Penetrance and Moderate- ... The investigators concluded, "Our findings indicated similar rates of bilateral mastectomy across high- and moderate-penetrance ...
Penetrance. OFD1 appears to be highly penetrant, although highly variable in expression. In some reports, renal cysts are the ...
"Penetrance" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical Subject ... Reduced penetrance in a large Caucasian pedigree with Stickler syndrome. Ophthalmic Genet. 2017 Jan-Feb; 38(1):43-50. ... Expression and penetrance of the hereditary pancreatitis phenotype in monozygotic twins. Gut. 2001 Apr; 48(4):542-7. ... This graph shows the total number of publications written about "Penetrance" by people in this website by year, and whether " ...
Penetrance. The penetrance of LRRK2 mutations has been a topic of intense study and debate. The most parsimonious models employ ... Penetrance in Parkinsons disease related to the LRRK2 R1441G mutation in the Basque country (Spain). Mov Disord. 2010 Oct 30. ... Penetrance estimate of LRRK2 p.G2019S mutation in individuals of non-Ashkenazi Jewish ancestry. Mov Disord. 2017 Oct. 32 (10): ... LRRK2 mutations have been shown to cause PD with age-related penetrance and clinical features identical to late-onset sporadic ...
Penetrance, in contrast, is more of a yes/no question ? does or does not the person have the disease. ... Penetrance, Variable Expressivity, and Gene Modifiers - Learn Science at Scitable. Understanding genetics: What are "penetrance ... Incomplete penetrance. The concept that even though several members of a family or population may have the same DNA mutation, ... Penetrance, in contrast, is more of a yes/no question ? does or does not the person have the disease. ...
Genetic penetrance. describes the heritability of factors, or the extent to which the features expressed are genetically ... Eye colour of course has high genetic penetrance, as does the overall statistical quality of the iris texture, but the textural ... Although the striking visual similarity of identical twins reveals the genetic penetrance of facial appearance, a comparison of ...
... a term called low penetrance, and also may produce mild or no symptoms, which is called low expressivity. We strive to educate ... Penetrance and Expressivity Impact Genetic Reporting. 17758 Views Posted on: February 6th 2019 Posted by: Martin schiller ... the penetrance is 48% by age 80. Other studies vary, but have similar variable penetrance. ... One part of this answer has to do with genetic penetrance, which is the percentage of people with a genetic variant that have a ...
Environment modulates the penetrance of genetic variants. Environmental factors not only directly affect phenotypic variation, ... More broadly, our work shows how environmental exposures modulate gene expression directly, can act upon the penetrance of ...
... 4 pages•Published: February 16, 2023. Borja González- ... Keyphrases: Epistasis model, Gene interaction, heritability, Penetrance, Prevalence, Python, simulation, Sympy. In: Alvaro ... Although it is very common for simulators to use penetrance tables, most of them do not allow the user to generate them ... In this work, we present PyToxo, a Python tool for generating penetrance tables from any-order epistasis models. PyToxo allows ...
To investigate whether common genetic variants modify penetrance for BRCA2 mutation carriers, we undertook a two-staged genome- ... These results indicate that SNPs that modify BRCA2 penetrance identified by an agnostic approach thus far are limited to ... To investigate whether common genetic variants modify penetrance for BRCA2 mutation carriers, we undertook a two-staged genome- ... Common genetic variants and modification of penetrance of BRCA2-associated breast cancer. ...
Penetrance of de novo mutation of usp9y and pcdh11y gene in azf regions of non-obstructive Azoospermic population in India. ... Conclusion: The identification of causative mutations in the cases of NOA and their penetrance lead to interference in ...
Explain the phenomenon of penetrance observed in autosomal dominant inheritance. May 22, 2020. /in Uncategorized /by Nursing ... 02Explain the phenomenon of penetrance observed in autosomal dominant inheritance.. ...
But within An effective and six its sent from the low-affected individuals, so the penetrance isnt done. Boys squares, girls ... Thus this sample could possibly get suffice to understand a dominant actually from lowest penetrance. ... when your penetrance is actually constant, the latest ratio from affecteds to normal is the exact same among the mother and ...
It also suggests that low penetrance susceptibility SNPs for breast, prostate and colorectal cancer are distinct. Although 8q24 ... Large scale association studies have identified low penetrance susceptibility alleles that predispose to breast cancer. A locus ... Low penetrance breast cancer predisposition SNPs are site specific. Mcinerney N., Colleran G., Rowan A., Walther A., Barclay E ... It also suggests that low penetrance susceptibility SNPs for breast, prostate and colorectal cancer are distinct. Although 8q24 ...
Penetrance. Complete after childhood in NF1. Test Interpretation. Methodology. This test is performed using the following ...
Penetrance. Variable, depending on the specific type of GSD. Test Interpretation. Clinical Sensitivity. Variable, depending on ...
The duplicated CREBBP gene within chromosome 16p13.3 is associated with incomplete penetrance regarding the mandible ... 16p13.3 duplication associated with non-syndromic pierre robin sequence with incomplete penetrance. *Mingran Sun1,2, ... Thus, our literature review suggested that the duplicated CREBBP gene was associated with incomplete penetrance regarding the ... It is also noteworthy that the duplicated CREBBP gene was associated with incomplete penetrance regarding the mandible ...
Standard Surveillance Definitions and Classifications for blood lead surveillance data.
Incomplete penetrance with normal MRI in a woman with germline mutation of the DCX gene. Neurology. 2001 Jul 24; 57(2):327-30. ... Incomplete penetrance with normal MRI in a woman with germline mutation of the DCX gene. ... Incomplete penetrance with normal MRI in a woman with germline mutation of the DCX gene. ...
De novo individualized disease modules reveal the synthetic penetrance of genes and inform personalized treatment regimens.. ... which enables us to elucidate the importance of mutated genes in specific patients and to understand the synthetic penetrance ...
Penetrance of 845G--, A (C282Y) HFE hereditary haemochromatosis mutation in the USA. Lancet. 2002 Jan 19. 359(9302):211-8. [ ...
  • Complete and incomplete or reduced penetrance: An allele is said to have complete penetrance if all individuals who have the disease-causing mutation have clinical symptoms of the disease. (wikipedia.org)
  • In incomplete or reduced penetrance, some individuals will not express the trait even though they carry the allele. (wikipedia.org)
  • An example of an autosomal dominant condition showing incomplete penetrance is familial breast cancer due to mutations in the BRCA1 gene. (wikipedia.org)
  • If some people with the variant do not develop features of the disorder, the condition is said to have reduced (or incomplete) penetrance. (medlineplus.gov)
  • The duplicated CREBBP gene within chromosome 16p13.3 is associated with incomplete penetrance regarding the mandible development anomalies. (biomedcentral.com)
  • Incomplete penetrance with normal MRI in a woman with germline mutation of the DCX gene. (uchicago.edu)
  • RESULTS: Incomplete penetrance of LQTS2 in KCNH2:p. (edu.au)
  • Penetrance may be complete or incomplete. (msdmanuals.com)
  • A gene with incomplete penetrance is not always expressed even when the trait it produces is dominant or when the trait is recessive and present on both chromosomes. (msdmanuals.com)
  • What are reduced penetrance and variable expressivity? (medlineplus.gov)
  • Reduced penetrance and variable expressivity are factors that influence the effects of particular genetic changes. (medlineplus.gov)
  • As with reduced penetrance, variable expressivity is probably caused by a combination of genetic, environmental, and lifestyle factors, most of which have not been identified. (medlineplus.gov)
  • Additional information about penetrance and expressivity is available from the Merck Manual Consumer Version. (medlineplus.gov)
  • Food selection is clearly an environmental exposure that can be controlled, and works with genetic variants to affect both penetrance and expressivity, which is the focus of Food Genes and Me . (foodgenesandme.com)
  • The millions of variants that each of us possess do really matter, after taking into account penetrance and expressivity . (foodgenesandme.com)
  • However, we are just in our infancy understanding penetrance and expressivity, which can show up as seemingly inaccurate statements in genetic reports. (foodgenesandme.com)
  • Two terms explain these differences: penetrance and expressivity. (msdmanuals.com)
  • Mutations in bone morphogenetic protein receptor type 2 ( BMPR2 ) cause familial pulmonary arterial hypertension (FPAH), but the penetrance is reduced and females are significantly overrepresented. (ersjournals.com)
  • However, it is unclear why BMPR2 mutations have reduced penetrance, and why, after puberty, females with mutations are about 2.5-fold more likely to develop FPAH than males 1 . (ersjournals.com)
  • LRRK2 mutations have been shown to cause PD with age-related penetrance and clinical features identical to late-onset sporadic PD. (medscape.com)
  • When variants have high penetrance, they are generally called mutations . (foodgenesandme.com)
  • Conclusion: The identification of causative mutations in the cases of NOA and their penetrance lead to interference in spermiogenesis .Hence, on the basis of mutational spectra, genetic counselling of infertile couples are required before reaching to final decision. (journalcra.com)
  • La neurofibromatosis tipo 1 es una enfermedad hereditaria disease with complete penetrance and is related to mutations in the NF1 de carácter autosómico dominante, con penetración completa y relacionada gene (17q11.2). (bvsalud.org)
  • Epigenetic regulation: Epigenetics can affect the penetrance of genes through genomic imprinting by the paternal or maternal allele or epigenetic regulation resulting from environmental or other personal factors. (wikipedia.org)
  • In a study reported in JAMA Oncology , Reid et al found that undergoing prophylactic bilateral mastectomy was as common in women with breast cancer with pathogenic/likely pathogenic variants in ATM and CHEK2 (moderate-penetrance genes) as in those with variants in BRCA1 , BRCA2 , or PALB2 (high-penetrance genes). (ascopost.com)
  • The objective of this study was to evaluate differences in surgical treatment across high- and moderate-penetrance breast cancer genes with differing clinical recommendations. (ascopost.com)
  • No significant differences in rates of bilateral mastectomy were observed among patients with variants in BRCA1 (42%), BRCA2 (44%), PALB2 (45%), ATM (55%), or CHEK2 (43%) (overall P = .73), and no significant difference was observed in comparison of the total groups of patients with high-penetrance vs moderate-penetrance genes (33% vs 36%, P = .47). (ascopost.com)
  • Similar rates of bilateral mastectomy across all five genes of varied penetrance are concerning, given that prophylactic contralateral mastectomy for risk reduction is considered only for high-penetrance genes, per national practice guidelines. (ascopost.com)
  • De novo individualized disease modules reveal the synthetic penetrance of genes and inform personalized treatment regimens. (bvsalud.org)
  • Our algorithm constructs individualized disease modules de novo, which enables us to elucidate the importance of mutated genes in specific patients and to understand the synthetic penetrance of these genes across patients . (bvsalud.org)
  • Combined with the reduced penetrance and variable phenotype, we conclude that KCNH2:p. (edu.au)
  • Penetrance in genetics is the proportion of individuals carrying a particular variant (or allele) of a gene (the genotype) that also expresses an associated trait (the phenotype). (wikipedia.org)
  • A consensus definition of what constitutes the presence of a phenotype is essential for determining the penetrance of an allele. (wikipedia.org)
  • Expression and penetrance of the hereditary pancreatitis phenotype in monozygotic twins. (ouhsc.edu)
  • The most common abstraction for specifying an epistasis interaction is through a penetrance table, which captures the probability of expressing the studied phenotype given a particular genotype. (easychair.org)
  • Penetrance is defined as the percentage of people who have the allele (the specific form of a gene responsible for the variations in which a given trait can be expressed) and who develop the corresponding phenotype (trait). (msdmanuals.com)
  • 119100) in a large inbred Arab family with an apparent autosomal dominant inheritance and reduced penetrance: clinical and genetic analysis. (ouhsc.edu)
  • Explain the phenomenon of penetrance observed in autosomal dominant inheritance. (nursinghomeworkdesk.com)
  • https://nursinghomeworkdesk.com/wp-content/uploads/2019/12/logo-300x60.png 0 0 Nursing Homework Desk https://nursinghomeworkdesk.com/wp-content/uploads/2019/12/logo-300x60.png Nursing Homework Desk 2020-05-22 11:23:02 2020-05-22 11:23:02 Explain the phenomenon of penetrance observed in autosomal dominant inheritance. (nursinghomeworkdesk.com)
  • Among females, there was four-fold higher penetrance among subjects homozygous for the wild-type genotype (N/N) than those with N/S or S/S genotypes (p = 0.005). (ersjournals.com)
  • Conclusions: One in 4 individuals with the MYOC p.Gln368Ter mutation demonstrated evidence of glaucoma, a substantially higher penetrance than previously estimated, with 69% of cases undetected. (ox.ac.uk)
  • As discussed above, the penetrance and severity of genetic disorders may not be the same for all persons. (alrc.gov.au)
  • Polygenic risk score increases disease penetrance and severity, supporting the usefulness of PRS in risk stratification among MYOC p.Gln368Ter carriers. (ox.ac.uk)
  • Genetic association studies may assess the influence of such variants on the penetrance of an allele. (wikipedia.org)
  • There are variants that are in 100% of affected people - this is called complete penetrance , where all individuals get the disease. (foodgenesandme.com)
  • Common genetic variants and modification of penetrance of BRCA2-associated breast cancer. (ox.ac.uk)
  • To investigate whether common genetic variants modify penetrance for BRCA2 mutation carriers, we undertook a two-staged genome-wide association study in BRCA2 mutation carriers. (ox.ac.uk)
  • These results indicate that SNPs that modify BRCA2 penetrance identified by an agnostic approach thus far are limited to variants that also modify risk of sporadic BRCA2 wild-type breast cancer. (ox.ac.uk)
  • However, only 60-85% of women with a BRCA1 mutation will develop breast cancer during their lifetimes (that is, 60-85% penetrance). (alrc.gov.au)
  • To test this, we studied the relationship between the CYP1B1 Asn453Ser ( N453S ) genetic polymorphism and FPAH penetrance in BMPR2 mutation carriers 19 . (ersjournals.com)
  • In medical genetics, the penetrance of a disease-causing mutation is the proportion of individuals with the mutation that exhibit clinical symptoms among all individuals with such mutation. (wikipedia.org)
  • A condition, most commonly inherited in an autosomal dominant manner, is said to show complete penetrance if clinical symptoms are present in all individuals who have the disease-causing mutation. (wikipedia.org)
  • 2.24 'Penetrance' is the term used to describe the degree of likelihood (based on clinical studies) that an individual carrying a particular genetic trait that could cause a disorder will actually develop it. (alrc.gov.au)
  • Reduced penetrance often occurs with familial cancer syndromes. (medlineplus.gov)
  • Genetic modifiers: Penetrance at a given allele may be polygenic, modified by the presence or absence of polymorphic alleles at other gene loci. (wikipedia.org)
  • For other alleles, the penetrance is lower-but this calculation is also dependent upon the definition of the disease. (alrc.gov.au)
  • Large scale association studies have identified low penetrance susceptibility alleles that predispose to breast cancer. (ox.ac.uk)
  • Recently, our studies of BMPR2 mutation carriers implicated altered oestrogen metabolism as a key factor in the penetrance of FPAH in females. (ersjournals.com)
  • Low penetrance breast cancer predisposition SNPs are site specific. (ox.ac.uk)
  • It also suggests that low penetrance susceptibility SNPs for breast, prostate and colorectal cancer are distinct. (ox.ac.uk)
  • Although an increasing number of copy-number variations are being identified as susceptibility loci for a variety of pediatric diseases, the penetrance of these copy-number variations remains mostly unknown. (nih.gov)
  • We sought to provide empiric estimates for penetrance for some of these recurrent, disease-susceptibility loci. (nih.gov)
  • Reduced penetrance in a large Caucasian pedigree with Stickler syndrome. (ouhsc.edu)
  • This implementation allows custom penetrance values and liability classes, and includes specialised pedigree visualisations. (univ-lyon1.fr)
  • For example, if a mutation in the gene responsible for a particular autosomal dominant disorder has 95% penetrance, then 95% of those with the mutation will develop the disease, while 5% will not. (wikipedia.org)
  • A condition which shows complete penetrance is neurofibromatosis type 1 - every person who has a mutation in the gene will show symptoms of the condition. (wikipedia.org)
  • Penetrance refers to the proportion of people with a particular genetic variant (or gene mutation) who exhibit signs and symptoms of a genetic disorder. (medlineplus.gov)
  • Penetrance of a given gene may vary from person to person and may depend on a person's age. (msdmanuals.com)
  • For many hereditary diseases, the onset of symptoms is age related, and is affected by environmental factors such as nutrition and smoking, as well as genetic cofactors and epigenetic regulation of expression: Age-related cumulative frequency: Penetrance is often expressed as a frequency of disease at different ages. (wikipedia.org)
  • For hereditary hemochromatosis, a disease caused by excess intestinal iron absorption, the degree of penetrance has been a subject of controversy for many years and illustrates the challenges facing investigators seeking a quantitative measure of penetrance. (wikipedia.org)
  • One part of this answer has to do with genetic penetrance, which is the percentage of people with a genetic variant that have a particular disease or trait. (foodgenesandme.com)
  • A new model for prediction of the age of onset and penetrance for Huntington's disease based on CAG length. (torvergata.it)
  • Mild tremor in relatives of patients with essential tremot: What does this tell us about the penetrance of the disease? (elsevierpure.com)
  • Dive into the research topics of 'Mild tremor in relatives of patients with essential tremot: What does this tell us about the penetrance of the disease? (elsevierpure.com)
  • But within An effective and six it's sent from the low-affected individuals, so the penetrance isn't done. (sportmasal.ir)
  • We aimed to understand the true population-wide penetrance and characteristics of glaucoma among individuals with the most common MYOC variant (p.Gln368Ter) and the impact of a POAG polygenic risk score (PRS) in this population. (ox.ac.uk)
  • Other studies vary, but have similar variable penetrance . (foodgenesandme.com)
  • It presents extremely variable expression and predisposition con mutaciones en el gen NF1 (17q11.2). (bvsalud.org)
  • High and low penetrance: If an allele is highly penetrant, then the trait it produces will almost always be apparent in an individual carrying the allele. (wikipedia.org)
  • Eye colour of course has high genetic penetrance, as does the overall statistical quality of the iris texture, but the textural details are uncorrelated and independent even in genetically identical pairs. (cam.ac.uk)
  • Although it is very common for simulators to use penetrance tables, most of them do not allow the user to generate them directly, or present limitations for high-order interac- tions and/or realistic prevalence and heritability values. (easychair.org)
  • inproceedings{XoveTIC2022:Generating_penetrance_tables_of, author = {Borja Gonz\textbackslash{}'alez-Seoane and Christian Ponte-Fern\textbackslash{}'andez and Jorge Gonz\textbackslash{}'alez-Dom\textbackslash{}'inguez and Mar\textbackslash{}'ia J. Mart\textbackslash{}'in}, title = {Generating penetrance tables of high-order epistasis models with PyToxo}, booktitle = {Proceedings of V XoveTIC Conference. (easychair.org)
  • Relevance of high and low penetrance. (cdc.gov)
  • Main Outcome Measures: Penetrance of glaucoma. (ox.ac.uk)
  • Even among older case relatives (≥60 years of age), there was an increased prevalence of higher tremor scores, suggesting that in that age group, subclinical ET may be present and penetrance still may not be complete. (elsevierpure.com)
  • It also provides insight into lifetime penetrance at various CAG lengths. (torvergata.it)
  • Penetrance can be difficult to determine reliably, even for genetic diseases that are caused by a single polymorphic allele. (wikipedia.org)
  • This graph shows the total number of publications written about "Penetrance" by people in this website by year, and whether "Penetrance" was a major or minor topic of these publications. (ouhsc.edu)
  • Below are the most recent publications written about "Penetrance" by people in Profiles. (ouhsc.edu)
  • Although the striking visual similarity of identical twins reveals the genetic penetrance of facial appearance, a comparison of genetically identical irises reveals just the opposite for iris patterns: the iris sequence is an epigenetic phenotypic feature, not a genotypic feature. (cam.ac.uk)
  • Common examples used to show degrees of penetrance are often highly penetrant. (wikipedia.org)
  • Reduced penetrance probably results from a combination of genetic, environmental, and lifestyle factors, many of which are unknown. (medlineplus.gov)
  • In this work, we present PyToxo, a Python tool for generating penetrance tables from any-order epistasis models. (easychair.org)
  • This model also defines the variability in HD onset that is not attributable to CAG length and provides information concerning CAG-related penetrance rates. (torvergata.it)
  • In cases of low penetrance, it can be difficult to distinguish environmental from genetic factors. (wikipedia.org)
  • Environmental modifiers: Penetrance may be affected by environmental factors. (wikipedia.org)
  • In one study the age-related penetrance of MEN1 was 7% by age 10 but nearly 100% by age 60. (wikipedia.org)
  • Such a study may provide information on the penetrance of ET. (elsevierpure.com)
  • 2.27 Table 2-1 contains further information about penetrance for a range of medical conditions. (alrc.gov.au)