Protean clinical manifestations in children with leukemias containing MLL-AF10 fusion

Translocations involving the MLL gene on chromosome 11q23 occur in 5-10% of human leukemias, and involve fusion with more than 30 different partner ge nes. The MLL-AF10fusion produced by the t(10;11)(p12;q23) or ins(10;11)(p12 ;q23q13) occurs in a small percentage of acute leukemias, most commonly acu te myelogenous leukemia (AML) of the M5 FAB sub-type. We report two cases o f AML (M5a and M0) and one case of acute lymphoblastic leukemia containing MLL-AF10 fusion. Each case had varied clinical characteristics, despite exp ressing similar MLL-AF10 fusion transcripts. including the three cases desc ribed in this report, we identified a total of 38 cases of leukemia with ML L-AF10 fusion. Approximately one-third of these are not M5 AML. Taken toget her, these findings emphasize that while the sentinel molecular event may b e identical in a disease, the clinical presentation and outcome can vary wi dely.