JAK2 V617F mutation in myeloproliferative neoplasms

ABSTRACT

Myeloproliferative neoplasms [MPNs] are clonal hematopoietic stem cell Malignancies characterized by excessive production of blood cellthey include polycythemia vera [PV],essential thrombocythemia [ET],Myelofibrosis [MF] and chronic inyeloid leukemia [CML].A somatic mutation in the Janus Kinase gene on chromosome 9 a guanine to thymine point mutation at nucleotide 1849 in exon 14,results in substitution of valine to phenylalanine atfcodon 617 this mutation contributes to the expansion of the MPN clone by increasing tyrosine phosphorylation activity providing hematopoietic [dh with a proliferative and survival advantage. The present work aimed to study the expression of JAK2 V617 F mutation by Real time PCR in myeloproliferative neoplasms patients. This study included /5 MPNs patients ;19 cases were diagnosed as PV 10 cases were diagnosed as ET16 cases were diagnosed as MF .20 age and sex matched individuals were also included as a control group. In MPNs patients,JAK2 mutation was expressed in 62%, in P V, ET an d MF patients 79%, 60% and 44% of cases had JAK2 mutation respectively. There was highly significant relationship between JAk2 mutation expression and patients' laboratory findings as regards hemoglobin level, total leucocytic count in PV positive JAK2 mutation patients and platelets count in ET positive JAK2 mutation patients. JAK2, mutation expression was associated with increased risk of MPNs .We concluded from this study that JAK2 mutation plays a fundamental role in the palhogenesis and development of MPNs ,and its detection is very useful to confirm the diagnosis and help in treatment and follow up of MPNs patients