For Some Single Gene Disorders, Some Members of a Family

question 23

Essay

For some single gene disorders, some members of a family who have the same genetic variants at the disease locus as strongly affected family members either show a much milder phenotype or no disease symptoms. List five explanations for why there can be a lack of penetrance or variable expressivity of a single gene disorder.

---

Definitions:

Probabilities

The measure of the likelihood that an event will occur, often expressed as a number between 0 and 1.

Values

The importance, worth, or usefulness of something, or a set of beliefs or standards of behavior.

Null Hypothesis

A statement suggesting that there is no significant difference or relationship between specified populations, any observed effect is due to sampling or experimental error.

Statistical Hypothesis

Statement about an expected outcome or relationship involving population parameters.