Carrier frequency

The proportion of individuals in a population who have a single copy of a specific recessive gene mutation; also sometimes applied to the prevalence of mutations in dominantly acting genes such as BRCA1 and BRCA2. Also called carrier rate

Assisted reproductive technology

ART. A term used to describe collectively a number of noncoital methods of conception that are used to treat infertility with donor or nondonor eggs and sperm including in vitro fertilization (IVF), gamete intrafallopian transfer (GIFT), and zygote intrafallopian transfer (ZIFT).

Phenotype

The observable characteristics in an individual resulting from the expression of genes; the clinical presentation of an individual with a particular genotype. (NCI Thesaurus)

Phenocopy

A phenotypic trait or disease that resembles the trait expressed by a particular genotype, but in an individual who is not a carrier of that genotype. For example, breast cancer in a hereditary breast/ovarian cancer syndrome family member who does not carry the family’s BRCA1 or BRCA2 mutation would be considered a phenocopy. Such an individual does not have the family’s cancer-related mutation and therefore, they do not have the associated cancer risk from that specific mutation.

Consanguinity

Genetic relatedness between individuals who are descendants of at least one common ancestor.

Codon

In DNA or RNA, a sequence of 3 consecutive nucleotides that codes for a specific amino acid or signals the termination of gene translation (stop or termination codon). (NCI Thesaurus)

Chromosome

Discrete physical structures inside a cell nucleus that consist of proteins and DNA organized into genes. (NCI Thesaurus)

Genomic imprinting

The process by which one chromosome of a pair is chemically modified, depending on whether the chromosome comes from the father or the mother. These modifications lead to differential expression of a gene or genes on a maternally derived chromosome versus a paternally derived chromosome. (NCI Thesaurus)

Clone

An identical copy of a DNA sequence or entire gene; one or more cells derived from and identical to a single ancestor cell OR to isolate a gene or specific sequence of DNA. (NCI Thesaurus)

Variant of unknown significance

VUS. A variation in a genetic sequence whose association with disease risk is unknown. Also called variant of uncertain significance, unclassified variant, and VUS

VUS

Variant of uncertain significance. A variation in a genetic sequence whose association with disease risk is unknown. Also called variant of uncertain significance, variant of unknown significance, and unclassified variant.

Variant of uncertain significance

VUS. A variation in a genetic sequence whose association with disease risk is unknown. Also called variant of unknown significance, unclassified variant, and VUS.

Locus

The physical site or location of a specific gene on a chromosome. (NCI Thesaurus)

Congenital

A condition or trait present at birth. It may be the result of genetic or nongenetic factors.

Affected

Individuals in a pedigree who exhibit the specific phenotype under study.