proportion of individuals with a mutation causing a particular disorder who
exhibit clinical symptoms of that disorder; a condition (most commonly inherited
in an autosomal dominant manner) is said to have complete penetrance if clinical
symptoms are present in all individuals who have the disease-causing mutation,
and to have reduced or incomplete penetrance if clinical symptoms are not
always present in individuals who have the disease-causing mutation
Definition from: GeneReviews
from the University of Washington and the National Center for Biotechnology Information
- The probability of a gene or genetic trait being expressed. "Complete" penetrance means the gene or genes for a trait are expressed in all the population who have the genes. "Incomplete" penetrance means the genetic trait is expressed in only part of the population. The percent penetrance also may change with the age range of the population.
Definition from: Human Genome Project Information
at the U.S. Department of Energy
Related discussion in the Handbook
See also Understanding Medical Terminology.