Accessible online at: www.karger.com/journals/aha

Key Words Acute myelogenous leukemia W Clonality W Residual disease W Southern blot At diagnosis, clonal gene rearrangement probes [retino-ic acid receptor (RAR)-·, major breakpoint cluster region (M-bcr), immunoglobulin (Ig)-JH, T cell receptor (TcR)-ß, myeloid lymphoid leukemia (MLL) or cytokine genes (GM-CSF, G-CSF, IL-3)] were detected in bone marrow samples from 71 of 153 patients with acute myelogenous leukemia (AML) (46%): in 41 patients with primary AML (pAML) (58%) and in 30 patients with secondary AML (42%). In all cases with promyelocytic leukemia (AML-M3) RAR- · gene rearrangements were detected (n = 9). Gene rearrangements in the Ig-JH or the TcR-ß or GM