BRCA

BRCA refers to two human genes, BRCA1 and BRCA2, that encode tumor suppressor proteins involved in the repair of double‑strand DNA breaks through homologous recombination. Pathogenic variants in these genes markedly increase the risk of several cancers, most notably breast and ovarian cancer in women and male breast cancer in men. BRCA1 mutations are associated with elevated risks of breast and ovarian cancers and cancers of the fallopian tube and peritoneum; BRCA2 mutations also raise breast cancer risk and increase susceptibility to pancreatic and prostate cancers, among others. The genes are inherited in an autosomal dominant pattern with variable penetrance, meaning not all carriers develop cancer but relatives have higher risk than the general population.

Testing and management often involve germline BRCA testing for individuals with personal or family history suggestive of hereditary cancer. Results influence decisions on intensified surveillance (such as earlier and more frequent MRI and mammography) and risk-reducing options, including prophylactic bilateral mastectomy or salpingo-oophorectomy, as well as discussion of chemopreventive measures where appropriate. In those who already have cancer, BRCA status informs treatment choices, as BRCA-mutant tumors are often more responsive to platinum chemotherapy and to PARP inhibitors—drugs such as olaparib, niraparib, and rucaparib that exploit synthetic lethality.

BRCA testing is frequently offered to at-risk relatives through cascade testing. In populations with founder mutations, such as some Ashkenazi Jewish groups, limited sets of BRCA1/BRCA2 variants account for a substantial portion of hereditary cases. BRCA status thus has implications for risk assessment, prevention, and targeted therapy.