Among 50 PMF patients, CALR mutations were detected in 11 (22.0%) and were also associated with higher platelet counts (P=0.035) and trended to a lower rate of cytogenetic abnormalities (P=0.059) than the JAK2V617F mutation.
Translocation t(1;9) is a recurrent cytogenetic abnormality associated with progression of essential thrombocythemia patients displaying the JAK2V617F mutation.
In the JAK2+ group, chromosome 7 and complex cytogenetic abnormalities were associated with excess blasts/blastic transformation (P < .05), whereas no cases with 20q- underwent blastic transformation.
We report the occurrence of a BCR-JAK2 fusion gene in a case of acute myeloid leukemia (AML) resulting from a t(9;22)(p24;q11) translocation as the sole cytogenetic abnormality.
Consistent with the concept of distinct pathogenetic mechanisms, we show that patients with and without the JAK2 mutation have different patterns of cytogenetic abnormality, with virtually all patients carrying the 20q deletion or trisomy 9 being V617F(+).