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Understanding Cancer Series

  • Posted: 01/28/2005
  • Reviewed: 09/01/2006

Slide 30


Factors Influencing Penetrance

Modifier genes affect the expression of some alleles, which may increase or decrease the penetrance of a germline mutation such as an altered cancer susceptibility allele. Penetrance may also be affected by mutations in DNA damage response genes, whose normal function is to recognize and repair genetic damage. If repair malfunctions, mutations may accumulate in other genes, increasing the likelihood that a given cell will progress to cancer.

Factors Influencing Penetrance