Marked granulocytic leukocytosis with basophilia is present, and chronic myeloid leukemia is suspected. Which finding most specifically supports the diagnosis?
1JAK2 V617F without other findings
2BCR::ABL1 fusion from t(9;22)✓ 정답
3Isolated factor V Leiden
4Loss of all immunoglobulin genes
해설
CML is defined by the BCR::ABL1 fusion, usually created by the Philadelphia chromosome translocation t(9;22).