Definition of penetrance in English:



mass nounGenetics
  • The extent to which a particular gene or set of genes is expressed in the phenotypes of individuals carrying it, measured by the proportion of carriers showing the characteristic phenotype.

    • ‘The penetrance of these phenotypes was background dependent.’
    • ‘However, other low penetrance susceptibility genes may exist which may alter individual predisposition to breast cancer.’
    • ‘Because of reduced penetrance, individuals of different genotypes can have the same phenotype.’
    • ‘High penetrance susceptibility genes probably account for no more than 5-10% of cases.’
    • ‘With the exception of the relatively rare high penetrance, single gene disorders, genetic tests differ little from most other medical tests, providing evidence of statistical risk only.’


1930s: from German Penetranz.