What is penetrance in genetic disorders?

What is penetrance in genetic disorders?

• A. The percentage of individuals showing a specific phenotype from a genetic mutation
• B. The degree of severity of a genetic disorder
• C. The total number of mutations in the gene
• D. The longevity of a genetic disorder

Answer: (A)

Penetrance refers to the proportion of individuals with a specific genotype that actually express the associated phenotype, meaning it quantifies how often a genetic mutation results in the expected observable trait or disorder. When a mutation is said to have complete penetrance, it means that 100% of those who carry the mutation exhibit the associated characteristics. Conversely, if a mutation has incomplete penetrance, not all individuals with the mutation will show the phenotype, which can lead to variability in the expression of genetic disorders within populations. Understanding penetrance is crucial for genetics and nursing practice, as it influences predictions about disease risk and informs counseling for patients and families regarding the implications of genetic information. The other options do not accurately describe penetrance. The degree of severity of a genetic disorder pertains to expressivity, not penetrance. The total number of mutations in a gene relates more to mutation burden than to the concept of penetrance. The longevity of a genetic disorder does not connect with how penetrance operates within a population or individual.

Penetrance refers to the proportion of individuals with a specific genotype that actually express the associated phenotype, meaning it quantifies how often a genetic mutation results in the expected observable trait or disorder. When a mutation is said to have complete penetrance, it means that 100% of those who carry the mutation exhibit the associated characteristics. Conversely, if a mutation has incomplete penetrance, not all individuals with the mutation will show the phenotype, which can lead to variability in the expression of genetic disorders within populations. Understanding penetrance is crucial for genetics and nursing practice, as it influences predictions about disease risk and informs counseling for patients and families regarding the implications of genetic information.

The other options do not accurately describe penetrance. The degree of severity of a genetic disorder pertains to expressivity, not penetrance. The total number of mutations in a gene relates more to mutation burden than to the concept of penetrance. The longevity of a genetic disorder does not connect with how penetrance operates within a population or individual.