penetrance
noun
pen·e·trance ˈpe-nə-trən(t)s 
: the proportion of individuals of a particular genotype that express its phenotypic effect in a given environment
Example Sentences
Recent Examples on the Web Sema4 only reports results for diseases that have a greater than 80 percent penetrance—the proportion of people with a genetic variant who end up developing the disease. 
Tanya Lewis, Scientific American, 24 Dec. 2019 Research suggests that random fluctuations in gene activity could explain some instances of the phenomenon, known as partial penetrance, which likely plays a role in some human diseases. Quanta Magazine, 22 May 2014
Tanya Lewis, Scientific American, 24 Dec. 2019 Research suggests that random fluctuations in gene activity could explain some instances of the phenomenon, known as partial penetrance, which likely plays a role in some human diseases. Quanta Magazine, 22 May 2014 Word History
Etymology
International Scientific Vocabulary, from Latin penetrare
First Known Use
1934, in the meaning defined above
Medical Definition
penetrance
noun
pen·e·trance ˈpen-ə-trən(t)s
: the proportion of individuals of a particular genotype that express its phenotypic effect in a given environment compare expressivity