Expressivity

As expressivity ( severity ) is called in genetics, the individual variation in levels of a phenotypic trait in identical genotype. Is this characteristic different despite identical genotype, it is called a variable expressivity. A variable expression can be caused for example by environmental influences during and after embryonic development.

Variable expressivity describes continuous features. It must be differentiated from the penetrance that categorically describes the actual frequency of a feature for a given genotype.

• Inheritance