Coexistence of BCR∷ABL1 translocation and JAK2V617F mutations in indian patients with myeloproliferative neoplasms: A case series.

ABSTRACT: BCR∷ABL1 translocation and JAK2V617F mutations are canonical variants of myeloproliferative neoplasms (MPNs). Traditionally considered mutually exclusive, they may rarely coexist. We report the clinicopathological profile and treatment outcomes of four MPN patients with coexistence of these disease-defining genetic variants. Both mutations were detected simultaneously in three patients who did not harbor tell-tale signs of CML and were evaluated for both BCR∷ABL1 and JAK2V617F based on clues from hemogram, peripheral-blood and bone-marrow examination. All were treated with imatinib and hydroxyurea and attained major molecular response after 2-7 months. In another patient, JAK2V617F was detected 15 years after the diagnosis of CML at the time of evaluation of loss of hematological and molecular response. She was treated with dasatinib but no hematologic or molecular response was attained after 6 months despite good compliance. In conclusion, BCR∷ABL1 and JAK2V617F may rarely coexist in MPN with variable temporal evolution, clinicopathological profile, and treatment response.