Infrequent V617F mutation of the JAK2 gene in myeloid leukemia and its absence in lymphoid malignancies in Japan

A unique mutation of the JAK2 gene, V617F, has recently been identified in polycythemia vera, essential thrombocythemia and myeloid metaplasia with myelofibrosis. To determine the relevance of this mutation in other types of hematological neoplasms in Japan, we performed allele-specific polymerase chain reaction analysis on the JAK2 gene. The V617F mutation was detected in one out of 130 myeloid neoplasms, but in none of 114 lymphoid malignancies and four biphenotypic acute leukemias. Although a favorable chromosomal alteration t(8;21)(q22;q22) was observed in one acute myeloid leukemia (AML) patient with the mutation, two courses of chemotherapy resulted in induction failure and short survival. Sequencing of JAK2 cDNA revealed expression of the mutant allele in the patient. The V617F mutation might play a role in the pathogenesis of certain AML cases.