Biology of Myeloproliferative Malignancies

Chronic myeloproliferative diseases (WHO, 2001), or myeloproliferative neoplasms/malignancies (MPN) (WHO, 2008), are clonal diseases characterized by proliferation of one or more myelopoietic cell line in the bone marrow with signs of unimpaired terminal differentiation and is normally associated with changes in peripheral blood characteristics. The group of classical Ph-negative MPNs consists of polycythemia vera, essential thrombocythemia, primary myelofibrosis and unclassified MPNs. Acquired somatic mutations contributing to the pathogenesis of Ph-negative MPNs include JAK2 (V617F, exon 12), MPL, CALR gene mutations found in about 90 % of patients. However, these molecular events are not unique in the pathogenesis of the diseases. Mutations of other genes (ТЕТ2, ASXL1, CBL, IDH1/IDH2, IKZF1, DNMT3A, SOCS, EZH2, TP53, RUNX1, and HMGA2) are involved in formation of the disease phenotype. This review describes current concepts concerning the molecular biology of MPNs.