All members of a family carry the same gene polymorphism associated with a certain phenotype. There is a range of phenotypes among the family members. What is the term for this observation?

Question

Quizplus · Accepted Answer

Variable expressivity refers to the observation that individuals with the same genotype can have different phenotypes. In this case, all family members carry the same gene polymorphism, but they have a range of phenotypes, indicating variable expressivity. Complete penetrance would mean that all individuals with the gene polymorphism would exhibit the phenotype, which is not the case here. X-linked and Y-linked refer to genes located on the sex chromosomes, and are not relevant to this scenario.

All Members of a Family Carry the Same Gene Polymorphism