Background and Aim: The JAK2 is an acquired mutation that is observed in majority of patients with classical Philadelphia-negative Myeloproliferative neoplasms that include polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF). This acquired mutation is characterized by a G to T transversion at nucleotide 1849 in exon 12 of the JAK2 gene, leading to a substitution of valine to phenylalanine at amino acid position 617(V617F) of the JAK2 protein, and result in constitutive JAK2 activation that promotes hypersensitivity to growth factors and cytokines.

Materials and Methods: In this study we evaluated RNA from 58 patients with MPNs and statistical analysis was done with mann whitney test. The mutation detected by AS-PCR. In addition, 3 samples were sequenced in Mille gen company.

Results: 46 patients:86.6%(26/30) of those with polycythemia vera, 53.3% (8/15) of those with essential thrombocythemia,61.5% (8/13) of those with idiopathic myelofibrosis polycythemia vera patient carrying the mutation displayed higher levels of WBC (p=0.03). on the other hand,16 out of 26 JAK2V617F positive patients were female there is a demonstrate correlation between the presence of a mutant allele and female gender. The difference in other groups were not significant.

Discussion and Conclusion: The JAK2V617F mutation has been detected in the vast majority of patients with polycythmia vera (65-95%) and in a lower frequency in patients with essential thrombocythemia (23-57%), idiopathic myelofibrosis (23-57%) and chronic myeloid leukemia 19% (3/16 CML Ph-). Detection of the mutation is helpful in differential diagnosis, prognosis, and prediction of therapeutic response.