JAK2(V617F) and leukemic transformation in myelofibrosis with myeloid metaplasia.

Amongst 42 consecutive patients with leukemic transformation (LT) from myelofibrosis with myeloid metaplasia (MMM) 72% carried the JAK2(V617F) mutation. The mutation was observed at expected frequencies in all subtypes of MMM and acute myeloid leukemia. Although the patients with the mutation were younger and had a shorter interval to LT there was no difference in survival. Additionally, both the lack of mutation status progression in serial analysis (available in nine patients) and the low frequency of patients with high mutated allele burden suggest that LT arising from MMM is probably not dependent on changes in JAK2(V617F) mutation status.