A 40-year-old man has AML with monocytic differentiation and 12% marrow eosinophils that contain large basophilic granules. Cytogenetics show inv(16)(p13q22). Which fusion gene is produced?
- A PML-RARA
- B RUNX1-RUNX1T1
- C CBFB-MYH11 ✓
- D KMT2A-AFF1
Correct answer: C. CBFB-MYH11
Explanation
Inversion of chromosome 16 fuses CBFB at 16p13 with MYH11 at 16q22, giving AML with inv(16), formerly FAB M4Eo. The dysplastic marrow eosinophils with abnormal basophilic granules are the morphologic clue. RUNX1-RUNX1T1 results from t(8;21), PML-RARA from t(15;17), and KMT2C-AFF1 from t(4;11), none of which produce abnormal eosinophils.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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