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Chronic myeloproliferative diseases is a group of clonal Ph-negative hematological diseases, which include erythremia (polycythemia Vera, PI), chronic megakaryocytic leukemia (essential thrombocythemia, ET) and subleukemicmyelosis (primary myelofibrosis, PMF, chronic idiopathic myelofibrosis). The origin of these diseases is linked to transformation of hematopoietic stem cells, the result is the excessive production of mature cells of erythroid, granulocytic and megakaryocyte shoots with relatively long course of the disease. The frequency of occurrence of mutation V617F of gene JAK2 exon 12 and MPL gene varies in different literature.

Determination of the frequency of occurrence of mutations in genes JAK2 and MPL and identifying the importance of the verification of these diseases.

The study included 350 patients with chronic myeloproliferative diseases — with polycythemia Vera 150 patients, with essential thrombocythemia 78, with chronic idiopathic myelofibrosis 55 and 67 patients were examined with the purpose of differential diagnosis with Ph(-) Chronic myeloproliferative diseases. The age of patients ranged from 20 to 70 years, median age was 54 years. Isolation DNA of patients was carried out using a set of reagents 'AmpliPrep RIBO-prep' (OOO Interlabservice, Russia). The concentration and purity of isolated DNA was determined by Nano Drop 2000 instrument (USA). Detection of gene mutation JAK2V617F and MPL gene was carried out by standard polymerase chain reaction on a thermal cycler 2720 'Applied Biosystems' (USA), using a set of 'Litech' (Moscow).

The result of the research showed that the incidence of the V617F mutation in JAK2 was varying in patients depending on the type of disease. In polycythemia Vera the mutation V617F in the JAK2 gene was identified in 147 patients of 150 (98,3 %), with essential thrombocythemia in 42 patients of the 78 (54,2 %), with chronic idiopathic myelofibrosis in 27 patients of 55 (49.1 %). In 67 patients with no hematological profile, wich examined with the purpose of differential diagnosis with Ph(-) chronic myeloproliferative diseases, V617F in JAK2 was detected in 6 (8,6 %), which allowed to confirm Ph(-) Chronic myeloproliferative diseases. A mutation in exon 12 of the JAK2 gene was detected in 2 of 33 (2,9 %) of those surveyed V617FJAK2-negative patients exclusively diagnosed with polycythemia Vera. The MPL W515L mutation gene was detected in polycythemia Vera and chronic idiopathic myelofibrosis 2.2 % (1 of 41) and 2 % (1 of 52) of patients.