A 35-year-old woman with a strong family history of breast and ovarian cancer is found to have a germline BRCA2 mutation. BRCA2 is involved in the repair of double-strand DNA breaks. Which specific DNA repair pathway is primarily affected by BRCA2 deficiency?

• A Base excision repair
• B Nucleotide excision repair
• C Non-homologous end joining
• D Homologous recombination ✓

Explanation

BRCA2 facilitates loading of RAD51 onto single-stranded DNA, a critical step in homologous recombination repair of double-strand breaks. Defects cause genomic instability and cancer predisposition. Non-homologous end joining is an error-prone pathway active throughout the cell cycle that does not require BRCA2. Base and nucleotide excision repair handle single-strand lesions, not double-strand breaks.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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