Detection of Jak2 V617f Mutation, Secondary to the Presence of Bcr-Abl1 Translocation in a Patient with Chronic Myeloid Leukemia: Report of a Case and Review of the Literature

The Myeloproliferative Neoplasms (MPN) are classified as four major diseases: Chronic Myeloid Leukemia (CML), Polycythemia Vera (PV), Primary Myelofibrosis (PMF) and Essential Thrombocythemia (ET) [1]. The translocation t(9;22)(q34;q11) produces the Philadelphia chromosome and causes the BCR-ABL1 transcript; this alteration is commonly found in CML [1]. In 2008 the World Health Organization (WHO) reported that MPN patients with the BCR-ABL1 transcript (Philadelphia positive) should be classified as chronic myeloid leukemia, and those who are Philadelphia negative (BCR-ABL1 negative) should be classified as Polycythemia Vera (PV), Essential Thrombocytosis (ET ) or myelofibrosis (PMF) [1]. JAK2 is a tyrosine kinase gene that has a role in the signaling pathways of hematopoietic factors. The JAK2 V617F mutation is found in 95% of PV patients, and 50% of ET and PMF patients [2,3]. Previously, it was thought that the JAK2 V617F mutation and BCR-ABL1 translocation were mutually exclusive. However a few rare cases have been reported that are positive for both alterations [4-17]. We report the first case in Central American with the presence of JAK2 V617F mutation, in a patient with the diagnosis of Philadelphia positive chronic myeloid leukemia.