A 52-year-old man has Hb 20 g/dL, hematocrit 58%, leukocytes 14,000/µL, platelets 550,000/µL, and a palpable spleen 4 cm below costal margin. Serum erythropoietin level is suppressed. Which molecular finding would confirm the diagnosis?
- A JAK2 V617F mutation ✓
- B BCR-ABL1 fusion transcript
- C CALR exon 9 frameshift mutation
- D FLT3 internal tandem duplication
Correct answer: A. JAK2 V617F mutation
Explanation
Polycythemia vera is a myeloproliferative neoplasm defined by panmyelosis with low erythropoietin, and more than 95% of patients carry the acquired JAK2 V617F mutation, which renders the erythropoietin signaling pathway constitutively active independent of the hormone. BCR-ABL1 indicates chronic myeloid leukemia, FLT3 ITD belongs to acute myeloid leukemia, and CALR mutations occur mainly in JAK2-negative essential thrombocythemia and primary myelofibrosis.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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