Frequency of Janus associated kinase 2 [JAK2] mutation in patients of BCR-ABL negative myeloproliferative neoplasms

ABSTRACT

To determine the frequency of Janus associated kinase 2 mutation in the patients of BCR-ABL negative classical myeloproliferative neoplasms. Cross-sectional descriptive study. Molecular Department of Haematology, Armed Forces Institute of Pathology [AFIP], Rawalpindi from Jul 2011 to Jul 2012. Ninety three consecutive patients of Polycythaemia vera [PV], Essential thrombocythaemia [ET] and Idiopathic myelofibrosis [IMF] diagnosed by the conventional haematological criteria were included in the study. All patients were screened for G-T point mutation [V617F] in the JAK2 gene on chromosome 9 by an allele specific PCR. Out of the 93 myeloproliferative neoplasm [MPN] patients, 33[35%] had polycythaemia vera, 36[39%] had essential thrombocythaemia and 24[26%] had idiopathic myelofibrosis. JAK2 mutation was seen in 64/93 [69%] patients including 33/33[100%] in PV, 19/36[52.6%] in ET and 12/24[50%] in IMF. Classical myeloproliferative neoplasms are an important group of heamatological disorder in our country. JAK2 gene mutation is seen in significant proportion of these disorders [69%]. JAK2 mutation analysis can be used to differentiate between polycythemia vera and secondary polycythemia in most cases with near certainty, where it was found in 100% of the cases