MLL gene rearrangement in t(9;11) acute myelogenous leukemia with minimal myeloid differentiation (FAB subtype M0)

A 25-year-old man was diagnosed with acute myelogenous leukemia (AML), Fren ch-American-British (FAB) subtype M0, based on cytochemical and flow cytome tric findings. Cytogenetic analysis revealed the chromosome translocations t(9;11)(p22;q23), and MLL gene rearrangement was identified by Southern blo tting. In adult AML, MLL gene rearrangement was initially reported in FAB M 4 and M5 cases, and recently in M1 and M2 cases, but was rare in M0 or M3 c ases. Because the sensitivity of detecting MLL gene rearrangement by cytoge netic analysis is extremely low compared with Southern blotting analysis, t he MLL gene may be involved in substantial numbers of adult AML cases, rega rdless of FAB subtype. Int J Hematol. 2000;71:245-248 (C) 2000 The Japanese Society of Hematology.