Familial breast cancer
(Science: oncology) a number of factors have been identified that increase the risk of breast cancer. One of the strongest of these risk factors is the history of breast cancer in a relative. About15-20% of women with breast cancer have such a family history of the disease, clearly reflecting the participation of inherited (genetic) components in the development of some breast cancers. Dominant breast cancer suceptibility genes, including BRCA1 and BRCA2, appear responsible for about 5% of all breast cancer. See related entries to: breast cancer susceptibility genes; BRCA1; BRCA2.
there are 2 genes; BRCA1 and BRCA2 which are susceptibility genes for breast cancer. They are inherited factors that predispose to breast cancer. Put otherwise, these genes make one more susceptible to the disease and so increase the risk of developing breast cancer. Two of these genes, BRCA1 and BRCA2, have been identified (and prominently publicised). Several other genes (those for the li-fraumeni syndrome, cowden disease, muir-torre syndrome, and ataxia-telangiectasia) are also known to predispose to breast cancer. However, since all of these known breast cancer susceptibility genes together do not account for more than a minor fraction (1/5th at most) of breast cancer that clusters in families, it is clear that more breast cancer genes remain to be discovered.