ABGC Certification Examination (CGC) key terms

The process of giving a client complete, understandable information about the benefits, risks, limitations, and alternatives of testing or research so they can decide voluntarily whether to proceed.

The ethical principle that people have the right to make their own decisions about their health and reproduction, even when others disagree with those choices.

The ethical duty to act in ways that promote the client's welfare and to weigh potential benefits when recommending testing, screening, or management options.

The ethical obligation to avoid causing harm, including minimizing psychological, social, and financial harms that can follow genetic testing or disclosure of results.

A counseling stance in which the counselor provides information and support without steering the client toward a particular reproductive or medical decision.

The counselor's duty to protect a client's genetic and personal information from disclosure to third parties without the client's permission, subject to legal exceptions.

The legal or ethical obligation, recognized in some jurisdictions, to alert at-risk relatives or authorities when a client's genetic condition poses serious preventable harm to others.

Unfair treatment of a person based on genetic information, such as in employment or insurance, which motivates protective laws and careful counseling about disclosure.

A session before genetic testing that covers the purpose of the test, possible results, inheritance implications, costs, and choices, so the client can give informed consent.

Systematic evaluation of a client's emotional state, family dynamics, culture, resources, and coping style to tailor genetic counseling and identify support needs.

An active communication skill in which the counselor reflects back the client's feelings and meaning to show understanding and build a working alliance.

Support offered after loss, such as a diagnosis, miscarriage, or death, that helps clients process emotions and adapt without imposing a timeline or expected reaction.

A standardized diagram using symbols and lines to show family relationships, health conditions, and inheritance patterns across generations.

The first affected family member through whom a family's genetic condition is identified and who anchors the pedigree drawing.

An inheritance pattern in which one altered copy of a gene is enough to cause a condition, often seen in every generation with affected parents transmitting to about half their children.

An inheritance pattern requiring two altered gene copies, typically producing affected siblings with unaffected carrier parents and a 25 percent recurrence risk per pregnancy.

A pattern in which a gene on the X chromosome causes disease more often in males, while carrier females may have mild or no symptoms.

Transmission of genetic traits through mitochondrial DNA, passed from mothers to all children, with variable severity due to heteroplasmy.

The proportion of people who carry a disease-causing genotype and actually show the associated clinical features.

The range of severity and type of clinical features among people who share the same disease-causing genotype.

A person who has one altered copy of a recessive or X-linked gene but usually does not show the condition and can pass the alteration to offspring.

A relationship between blood relatives, such as first cousins, that increases the chance both partners carry the same recessive alteration.

A stepwise approach in which relatives of a person with a known pathogenic variant are offered targeted testing in order of genetic closeness.

A laboratory test that visualizes the number and structure of chromosomes to detect aneuploidy, translocations, and large deletions or duplications.

A test that detects small chromosomal deletions and duplications across the genome at higher resolution than a standard karyotype.

A deletion or duplication of a chromosomal segment that may be benign, pathogenic, or of uncertain significance depending on size, gene content, and inheritance.

A genetic change whose link to disease is not yet established, requiring careful counseling because it should not usually guide medical management.

A genetic alteration with strong evidence of causing disease, which may inform diagnosis, surveillance, and risk estimates for relatives.

An abnormal number of chromosomes, such as trisomy 21, that can be detected prenatally through screening or diagnostic testing.

A non-diagnostic test, such as maternal serum screening or cell-free DNA, that estimates the chance of certain fetal conditions and may lead to diagnostic testing.

Testing to identify people who carry a recessive or X-linked alteration before pregnancy so they can learn reproductive risks and options.

The presence of both normal and altered mitochondrial DNA within a cell or tissue, which contributes to variable severity of mitochondrial disease.

The probability that a condition will occur again in a family, calculated from inheritance pattern, family history, and test results.

Explaining probabilities in clear, accessible ways, such as natural frequencies, to help clients understand test results and make informed choices.

A structured record of health conditions and ages at diagnosis among relatives, used to estimate risk and guide testing decisions.