A 52-year-old man from West Africa presents with a liver mass. Biopsy confirms hepatocellular carcinoma. Molecular analysis reveals a G:C to T:A transversion at codon 249 of the TP53 gene. Which carcinogen is most strongly associated with this specific mutation signature?
- A Aflatoxin B1 ✓
- B Asbestos
- C Vinyl chloride
- D Aristolochic acid
Correct answer: A. Aflatoxin B1
Explanation
Aflatoxin B1, produced by Aspergillus flavus, causes a characteristic G:C to T:A transversion at codon 249 (AGG to AGT, Arg to Ser) of TP53. This mutation signature is highly specific and is the molecular hallmark linking aflatoxin exposure to hepatocellular carcinoma. Vinivl chloride causes angiosarcoma of the liver. Aristolochic acid causes A:T to T:A transversions in urothelial carcinoma.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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