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.
The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."
Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
The magnitude of INBREEDING in humans.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
The different ways GENES and their ALLELES interact during the transmission of genetic traits that effect the outcome of GENE EXPRESSION.
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)
Quantitative Trait, Heritable
Genes that influence the PHENOTYPE only in the homozygous state.
Genetic Predisposition to Disease
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.
Nonrandom association of linked genes. This is the tendency of the alleles of two separate but already linked loci to be found together more frequently than would be expected by chance alone.
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.
A family composed of spouses and their children.
Polymorphism, Single Nucleotide
Chromosomes, Human, Pair 1
Hip Dysplasia, Canine
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)
Optic Atrophy, Hereditary, Leber
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))
Age of Onset
The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.
Chromosomes, Human, Pair 2
Genetic Diseases, Inborn
An individual in which both alleles at a given locus are identical.
A republic consisting of a group of about 100 islands and islets in the western Pacific Ocean. Its capital is Koror. Under Spain it was administered as a part of the Caroline Islands but was sold to Germany in 1899. Seized by Japan in 1914, it was taken by the Allies in World War II in 1944. In 1947 it became part of the U.S. Trust Territory of the Pacific Islands, became internally self-governing in 1980, obtained independent control over its foreign policy (except defense) in 1986, and achieved total independence October 1, 1994. (Webster's New Geographical Dictionary, 1988, p915; telephone communication with Randy Flynn, Board on Geographic Names, 17 January 1995)
A stochastic process such that the conditional probability distribution for a state at any future instant, given the present state, is unaffected by any additional knowledge of the past history of the system.
Chromosomes, Human, Pair 19
Chromosomes, Human, Pair 3
Monte Carlo Method
In statistics, a technique for numerically approximating the solution of a mathematical problem by studying the distribution of some random variable, often generated by a computer. The name alludes to the randomness characteristic of the games of chance played at the gambling casinos in Monte Carlo. (From Random House Unabridged Dictionary, 2d ed, 1993)
Chromosomes, Human, Pair 13
Chromosomes, Human, Pair 5
Chromosomes, Human, Pair 10
Optic Atrophies, Hereditary
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).
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)
Genome-Wide Association Study
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
Chromosomes, Human, Pair 7
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Asian Continental Ancestry Group
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.
Chromosomes, Human, Pair 20
Polymorphism, Restriction Fragment Length
Chromosomes, Human, Pair 6
Chromosomes, Human, Pair 4
Chromosomes, Human, Pair 12
Sequence Analysis, DNA
Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.
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.
That part of the genome that corresponds to the complete complement of EXONS of an organism or cell.
Chromosomes, Human, Pair 17
Polymerase Chain Reaction
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Corneal Dystrophies, Hereditary
The apparent tendency of certain diseases to appear at earlier AGE OF ONSET and with increasing severity in successive generations. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Chromosomes, Human, Pair 16
A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta.
A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.
Chromosomes, Human, Pair 9
Duane Retraction Syndrome
A syndrome characterized by marked limitation of abduction of the eye, variable limitation of adduction and retraction of the globe, and narrowing of the palpebral fissure on attempted adduction. The condition is caused by aberrant innervation of the lateral rectus by fibers of the OCULOMOTOR NERVE.
Brachial Plexus Neuritis
A syndrome associated with inflammation of the BRACHIAL PLEXUS. Clinical features include severe pain in the shoulder region which may be accompanied by MUSCLE WEAKNESS and loss of sensation in the upper extremity. This condition may be associated with VIRUS DISEASES; IMMUNIZATION; SURGERY; heroin use (see HEROIN DEPENDENCE); and other conditions. The term brachial neuralgia generally refers to pain associated with brachial plexus injury. (From Adams et al., Principles of Neurology, 6th ed, pp1355-6)
Polymorphism, Single-Stranded Conformational
Variation in a population's DNA sequence that is detected by determining alterations in the conformation of denatured DNA fragments. Denatured DNA fragments are allowed to renature under conditions that prevent the formation of double-stranded DNA and allow secondary structure to form in single stranded fragments. These fragments are then run through polyacrylamide gels to detect variations in the secondary structure that is manifested as an alteration in migration through the gels.
A group of nine islands and several islets belonging to Portugal in the north Atlantic Ocean off the coast of Portugal. The islands are named after the acores, the Portuguese for goshawks, living there in abundance. (Webster's New Geographical Dictionary, 1988, p102 & Room, Brewer's Dictionary of Names, 1992, p42)
Sex Chromosome Aberrations
Abnormal number or structure of the SEX CHROMOSOMES. Some sex chromosome aberrations are associated with SEX CHROMOSOME DISORDERS and SEX CHROMOSOME DISORDERS OF SEX DEVELOPMENT.
Animals which have become adapted through breeding in captivity to a life intimately associated with humans. They include animals domesticated by humans to live and breed in a tame condition on farms or ranches for economic reasons, including LIVESTOCK (specifically CATTLE; SHEEP; HORSES; etc.), POULTRY; and those raised or kept for pleasure and companionship, e.g., PETS; or specifically DOGS; CATS; etc.