PREVALENCE AND CLINICAL CORRELATIONS OF MLL GENE REARRANGEMENTS IN AML-M4 5/

Rearrangements of the human trithorax gene (MLL, HRX, Htrx-1, All-1) w ere studied by Southern blotting in blast cells stored at presentation from 65 adults with de novo acute myelomonocytic (AML-M4) and acute m onocytic leukemia (AML-M5). MLL rearrangements were demonstrated in 15 (23%) cases, including eight patients in whom karyotype analysis had failed to detect abnormalities of chromosome band 11q23. The patients with MLL rearrangements did not differ significantly from those with g ermline configurations in terms of the sex and age of the patients, th e presence of lymphadenopathy, hepatosplenomegaly, or central nervous system involvement, and the absolute blast count at diagnosis. Kaplan- Meier analysis of the treated patients demonstrated no difference in s urvival for patients with MLL rearrangements compared with those witho ut rearrangements. Therefore, in contrast to infantile acute leukemia, in adults with AML-M4 and AML-M5, MLL rearrangements do not identify a subgroup of patients with different clinical features or prognosis. (C) 1994 by The American Society of Hematology.