The Role of Janus Kinase 2 (JAK2) in the Pathologenesis of Myeloproliferative Disorders

Abstract. The myeloproliferative disorders, polycythemia vera, essential thombocythemia, and primary myelofibrosis are clonal disorders of multipotent hematopoietic progenitors. The genetic cause of these diseases was not known until 2005, when several independent groups demonstrated that most patients with PV, ET and PMF acquired a single point mutation in the cytoplasmic tyrosine kinase, such as JAK2 (JAK2 V617F). These discoveries have changed the landscape for diagnosis and classification of PV, ET and PMF, and have shown the ability of genomic technologies to identify new molecular targets in human malignancies with pathogenetic, diagnostic and therapeutic significance.