Penetrance (mutations) - Wikipedia, the free encyclopedia

Associated terminology

• complete penetrance. The allele is said to have complete penetrance if all individuals who have the disease-causing mutation have clinical symptoms of the disease.
• highly penetrant. If an allele is highly penetrant, then the trait it produces will almost always be apparent in an individual carrying the allele.
• incomplete penetrance or reduced penetrance. Penetrance is said to be reduced or incomplete when some individuals fail to express the trait, even though they carry the allele.
• low penetrance. An allele with low penetrance will only sometimes produce the symptom or trait with which it has been associated at a detectable level. In cases of low penetrance, it is difficult to distinguish environmental from genetic factors.

Germline Genetic Variation, Cancer Outcome, and Pharmacogenetics — JCO

Abstract

"Studies of the role of germline or inherited genetic variation on cancer outcome can fall into three distinct categories. First, the impact of highly penetrant but lowly prevalent mutations of germline DNA on cancer prognosis has been studied extensively for BRCA1 and BRCA2 mutations as well as mutations related to hereditary nonpolyposis colorectal cancer syndrome (Lynch Syndrome). ...."cont'd

Candidate gene association studies: successes and failures

Abstract

"Epidemiologic studies of twins indicate that 20-40% of common tumors such as breast, colorectal, and prostate cancers are inherited. However, the effect of high penetrance tumor susceptibility genes such as APC, BRCA1, BRAC2, MSH1, MLH2 and MSH6 only accounts for a small fraction of these cancers. Low to moderate penetrance tumor susceptibility genes likely account for the large remaining proportion of familial cancer risk...."