Penetrance

Penetrance refers to the proportion of individuals with a specific genetic variant who actually express the associated trait or condition. In simpler terms, it indicates how often a genetic mutation will result in a visible effect. For example, if a genetic trait has 80% penetrance, it means that 80 out of 100 people with the mutation will show the trait, while 20 will not, despite carrying the same genetic change. Factors like environment and other genes can influence penetrance, leading to variability in expression among individuals with the same genotype.