Do inherited mutations in other genes increase the risk of breast and/or ovarian tumors?

Yes. Mutations in several other genes, including TP53, PTEN, STK11/LKB1, CDH1, CHEK2, ATM, MLH1, and MSH2, have been associated with hereditary breast and/or ovarian tumors. However, the majority of hereditary breast cancers can be accounted for by inherited mutations in BRCA1 and BRCA2. Overall, it has been estimated that inherited BRCA1 and BRCA2 mutations account for 5 to 10 percent of breast cancers and 10 to 15 percent of ovarian cancers among white women in the United States.