Evaluation of JAK2V617F mutation prevalence in myeloproliferative neoplasm by AS-RT-PCR

Objective JAK2 is a non-receptor tyrosine kinase that plays a major role in myeloid disorders. JAK2V617F mutation is characterized by a G to T transverse at nucleotide 1849 in exon 12 of the JAK2 gene, located on the chromosome 9p, leading to a substitution of valine to phenylalanine at amino acid position 617 in the JAK2 protein. Methods In this study we evaluated RNA from 89 patients with MPNs and statistical analysis done with Mann-Whitney test. The mutation detected by allele specific-PCR(AS-PCR). In addition, 3 samples were sequenced in Millegen company.ResultsUsing AS-PCR method 26/30 polycythemia vera patients (86%), 8/13 IMF patients (61%), 8/15 ET patients (53%) and none of 31 CML patients were positive for JAK2 V617F mutation.Polycythemia vera patient carrying the mutation displayed higher levels of WBC (p=0.03). Sixteen of 26 JAK2V617F positive patients were female that demonstrate correlation between the presence of a mutant allele and sex. The differences in other groups were not significant.ConclusionWe have shown that a single acquired point mutation in JAK2 is present in virtually most patients with PV and in about half of those with either ET or IMF.However in other studythe JAK2V617F mutation has been detected in the vast majority of patients with polycythmia vera (65-95%). It was less frequent 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.