Genetic and Genomic Terms Glossary PDF

## TABLE 12.1 Glossary of Genetic and Genomic Terms | Term | Definition | |---|---| | Allele | One of a series of alternative forms (genotypes) at a specific region (locus) of a chromosome | | Autosome | A chromosome other than X or Y. The human genome has 44 autosomes (22 pairs of autosomes) | | C...

## TABLE 12.1 Glossary of Genetic and Genomic Terms | Term | Definition | |---|---| | Allele | One of a series of alternative forms (genotypes) at a specific region (locus) of a chromosome | | Autosome | A chromosome other than X or Y. The human genome has 44 autosomes (22 pairs of autosomes) | | Carrier | A person who is heterozygous for a gene variant that causes autosomal recessive or X-linked recessive disease. Used to describe heterozygotes for risk alleles of complex traits with variable penetrance, regardless of inheritance type | | Carrier rate | Frequency of carriers in a population | | Carrier testing | Clinical method used to identify at-risk family members of populations, who are usually asymptomatic but may have a pathogenic variant for an autosomal recessive or X-linked disorder | | Chromosome | Microscopic structures in the cell nucleus composed of chromatin, which contain genetic information. Each cell normally has 46 chromosomes in 23 pairs (22 autosome pairs and 2 sex chromosomes) | | Codominance | Expression of each pair of alleles when present in the heterozygous state (e.g., AB blood type) | | Congenital | Present at birth | | Consanguineous | Reproduction between 2 persons from the same bloodline, such as first or second cousins. Consanguineous parentage increases the probability of a rare recessive disease | | Dominant allele | Gene that is expressed in the phenotype of a heterozygous person | | Familial disorder | A trait that appears with higher frequency among close relatives than in the general population | | Gene | Functional unit of heredity. A gene is a unit of DNA sequence that encodes for a specific functional product, such as RNA | | Genetic risk | Probability that a trait will occur or recur in a family, based on knowledge of its genetic pattern of transmission | | Genetics | Study of genes and their role in inheritance | | Genome | All the DNA contained in a person. A person's genetic constitution | | Genome-wide association study (GWAS) | A type of genetic mapping study design that involves scanning complete sets of DNA (genomes) of many people to find genetic variations associated with a particular disease | | Genomics | Study of how genes interact and influence people's biologic and physical characteristics | | Genotype | Genetic identity of a person, comprised of the entire complex of genes inherited from both parents | | Haploid | Cells or organisms that have 1 copy of each autosomal chromosome and 1 copy of each sex chromosome. Ova and sperm are haploid. Fertilization results in an embryo with 1 set of chromosomes from each parent (diploid embryo) | | Hereditary | Transmission of a disease, condition, or trait from parent to children | | Heterozygous | Having 2 different alleles for 1 given gene, 1 inherited from each parent | | Homozygous | Having 2 identical alleles for 1 given gene, 1 inherited from each parent | | Locus | Position of a gene on a chromosome | | Mutation | A change in a gene that affects function. Types include nonsense, missense silent, and frameshift. A mutation associated with a disease is called a pathogenic variant. Sometimes mutations are passed from parent to children. | | Oncogene | Gene that contributes to the conversion of normal cells to cancer cells. Usually dominant | | Pedigree | A graphic representation that shows family relationships, gender, age, and presence of diseases for each family member | | Pharmacogenetics | Study of variability of drug metabolism related to variations in single genes | | Pharmacogenomics | Study of variability of drug metabolism in relation to variations in and interactions of multiple genes or the person's genome | | Phenotype | Observable characteristics of a person. Can be measured categorically or quantitatively | | Protooncogene | Genes that can be turned into oncogenes by a dominant activating mutation. Oncogenes synthesize structurally altered proteins that result in cancer | | Recessive allele | Allele that has no noticeable effect on the phenotype in a heterozygous person | | Trait | Physical characteristic that one inherits, such as hair or eye color | | X-linked gene | Gene found on the X chromosome rather than an autosome. In general, sex-linked disorders are seen in males |