Inherited genetic syndromes are also associated with the development of ovarian cancer. The most common hereditary form of ovarian cancer is associated with the BRCA1, BRCA2, and the mismatch repair genes MLH1, MSH2, MSH6, and PMS2. These genes normally act to prevent the abnormal growth of cells and to help repair DNA damage. When mutated, or altered, these genes can increase the risk of developing cancer. In fact, germline mutations in these genes are present in approximately 15% of ovarian cancer cases.
Recently, germline mutations in a number of other DNA repair genes were detected in ovarian cancer patients and have been associated with an increased risk of the disease. Such genes include BRIP1, NBN, BARD1, PALB2, RAD51C, RAD51D and others in the Fanconi Anemia pathway.
For women with a mutation of the BRCA1 gene the lifetime risk of ovarian cancer is estimated to be 35-70%. For women who harbor a BRCA2 mutation, the risk of ovarian cancer is 10-30%. Women diagnosed with ovarian cancer are now commonly tested for BRCA gene mutations. Those women who harbor a BRCA mutation but have not developed an ovarian cancer usually undergo surveillance monitoring or prophylactic surgery.