Abstract
JAK2 V617F and MPL W515L/K mutations have been reported in approximately 50% and 5% of the patients with essential thrombocythemia (ET), respectively. We investigated the frequency of MPL W515L/K mutations in a series of consecutive patients with ET and post-essential thrombocythemia myelofibrosis (post-ET MF). The study subjects were 63 patients diagnosed either with ET (N=59) or post-ET MF (N=4) at our institution between June 2006 and February 2010. Among them, 35 (55.6%) had the JAK2 V617F mutation. MPL W515L/K mutations were detected by direct sequencing analyses of exon 10, and 2 patients were found to harbor the following MPL mutations: W515L in 1 patient with ET and W515K in 1 patient with post-ET MF. Neither of the patients had the JAK2 V617F mutation. The frequencies of the MPL W515L/K and JAK2 V617F-negative mutations in our subjects with ET/post-ET MF were 3.2% (2/63) and 7.1% (2/28), respectively. This is the first study to report the frequency of JAK2 V617F and MPL W515L/K mutations in Korean patients with ET/post-ET MF.
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Fig. 1.
MPL gene mutations in 2 Korean patients with myeloproliferative neoplasms. Patient 1 with essential thrombocythemia (ET) had the W515L mutation from c.1544G>T with an allele burden of approximately 50%. Patient 2 with post-ET myelofibrosis had W515K from c.1543_1544TG>AA with an allele burden of approximately 100% (homozygous).
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