ABSTRACT
<p><b>OBJECTIVE</b>To detect JAK2 V617F mutation burden and its clinical implications in patients with myeloproliferative neoplasm (MPN).</p><p><b>METHODS</b>JAK2 V617F mutation burden were detected by using MGB Taqman probes and its clinical significance were retrospectively studied in 415 MPN patients.</p><p><b>RESULTS</b>JAK2 V617F was found in 56.9% of all patients [83.5% in polycythemia vera (PV), 55.9% in essential thrombocythemia (ET), 41.9% in primary myelofibrosis (PMF) and 64.7% in MPN-unclassifiable)]. The majority of patients carried heterozygous JAK2 V617F mutation and homozygote was found only in 12 cases (4 in PV, 4 in MPN-U, 2 in PMF, 1 in ET, and 1 in chronic neutrophilic leukemia). Most patients (68.8%) were lower mutation burden (mutation burden<50%), but PV had the highest burden, the moderate burden in PMF and the least in ET. The patient's age and WBC count were significantly correlated with higher mutation burden in PV. WBC count was significantly related to higher mutation burden in ET. WBC count, Hb level and the platelet count were significantly related to higher mutation burden in PMF.</p><p><b>CONCLUSION</b>The mutation burden of JAK2 V617F from high to low was PV, ET and PMF. The majority of JAK2 V617F mutation was heterozygous. JAK2 V617F mutation burden was positively correlated with age, WBC, Hb and platelet counts.</p>