A study of JAK2 (V617F) gene mutation in patients with chronic myeloproliferative disorders

Chronic myeloproliferative diseases (MPDs) are heterogenous group of haematological malignant disorders. It is now a well recognized fact that the JAK2 (V617F) mutation occurs in majority of the patients with polycythaemia vera (PV) and half of those with myelofibrosis and essential thrombocythaemia. The presence of JAK2 (V617F) mutation is considered an important criterion for the exclusion of secondary-reactive from clonal disorders. In the present uni-institutional study, we analyzed the JAK2 (V617F) mutation status in the ethnic Malay and Chinese patients who were diagnosed as MPDs.

The study was performed on known cases of chronic MPDs either at diagnosis or during the follow-up. A total of 45 cases were studied with informed consent. The allele specific PCR, ARMS-PCR and RQ-PCR methods were used.

The frequency of the JAK2 (V617F) mutation varied between the MPD subtypes, with the mutation being most frequent in PV (95.8%) and 39% showed homozygous mutant allele. The mutation was detected in 52.9% cases of ET, of which 36.4% were homozygous for the mutant allele and 1 case of MF was homozygous for the mutant allele.

Screening for the mutation in all cases suspected of chronic MPD could be beneficial in differentiating patients with reactive erthrocytosis or thrombocytosis from the true clonal MPDs especially polycythaemia vera.