Ovarian carcinomas are associated with which mutation or marker?

• A. BRCA1/2
• B. MSI
• C. TP53
• D. CA125

Answer: (A)

BRCA1/2 mutations are the best-known hereditary risk factor for ovarian carcinomas because these genes are essential for repairing double-strand breaks through homologous recombination. When BRCA1 or BRCA2 carry pathogenic mutations, this repair process falters, leading to genomic instability and a higher likelihood of developing ovarian cancer, especially the high-grade serous type. Clinically, this link is important not just for risk assessment but also for treatment options, since BRCA-mutant tumors often respond well to platinum-based chemotherapy and to PARP inhibitors that target the remaining DNA repair weakness. In contrast, CA125 is a serum marker used to monitor disease, not a mutation; MSI reflects mismatch repair defects typical of other cancers, and TP53 mutations are common in many ovarian cancers but do not represent the inherited predisposition highlighted by BRCA1/2.