CGC Population Genetics & Epidemiology 2

Question 1

Penetrance in genetics refers to:

Accepted Answer

The proportion of individuals with a given genotype who exhibit the associated phenotype

Answer

Penetrance is the proportion of individuals with a pathogenic genotype who show clinical features; incomplete penetrance means not all carriers are affected.

Question 2

Variable expressivity in genetics means:

Accepted Answer

Individuals with the same pathogenic variant may show different degrees or types of clinical features

Answer

Variable expressivity describes the range in clinical severity or phenotypic features seen among individuals who share the same pathogenic variant.

Question 3

Which measure of disease frequency represents the proportion of a population affected with a condition at a specific point in time?

Accepted Answer

Point prevalence

Answer

Point prevalence measures the proportion of individuals in a population who have a condition at a specific moment in time.

Question 4

Locus heterogeneity refers to the situation where:

Accepted Answer

Mutations at different gene loci can all cause the same clinical phenotype

Answer

Locus heterogeneity means clinically similar conditions can result from variants in different genes, complicating genetic testing interpretation.

Question 5

Allelic heterogeneity refers to:

Accepted Answer

Multiple different variants within the same gene causing the same or related phenotypes

Answer

Allelic heterogeneity describes the existence of multiple distinct pathogenic variants within the same gene that all produce the same or similar phenotype.

CGC - Certified Genetic Counselor Practice Test

CGC - Certified Genetic Counselor Practice Test

CGC Population Genetics & Epidemiology 2