Hereditary Breast and Ovarian Cancer Mutations in breast cancer genes, BRCA1 and BRCA2, are the most common cause of hereditary breast and ovarian cancer (up to 90% in some populations). Proteins encoded by these genes help repair DNA damage and suppress tumor growth. Inherited mutations in BRCA1 and BRCA2 can increase the risk for developing breast and ovarian cancer as well as other types of cancer (Figure & Table below). Additional genes have been linked to increased risk of breast and other cancers and have National Comprehensive Cancer Network (NCCN) guidelines for screening and preventive management. BRCA1 ~Breast, ovarian, pancreatic, prostate BRCA2 ~Breast, ovarian, pancreatic, prostate, melanoma CHEK2 ~Breast, colorectal, prostate ATM ~Breast, ovarian, pancreatic, prostate PALB2 ~Breast, pancreatic, prostate TP53 ~Breast, soft-tissue sarcomas, brain, adrenocortical (Li-Fraumeni syndrome) CDH1 ~Diffuse gastric, breast (lobular) PTEN ~Breast, uterine, skin, thyroid, brain, colorectal (Cowden syndrome) NF1 ~Breast, gastric (GIST), pancreatic NBN ~Breast, prostate STK11 ~Breast, colorectal, gastric, pancreatic, ovarian, uterine (Peutz-Jeghers syndrome) Gene~Associated Cancer Predisposition Henry Ford Center for Precision Diagnostics