Translocation (8;17;15;21)(q22;q23;q15;q22) in acute myeloid leukemia (M2): a four-way variant of t(8;21)

We report the results of cytogenetic. fluorescence in situ hybridization (F ISH) and molecular analyses in a 15-year-old boy diagnosed with acute myelo id leukemia subtype: M2 (AML-M2). Cytogenetic and FISH analyses, the latter with whole chromosome painting probes, revealed a complex translocation in volving lour chromosomes: t(8:17:15:21)(q22:q23;q15:q22). The observation o f breakpoints at t;q22 and 21q22 suggested a rearrangement of the ETO and A ML1 genes, respectively. Using a dual-color FISH test with ETO and AML1 pro bes, we demonstrated an AML1/ETO fusion signal on the derivative chromosome 8. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showe d the presence of AML1/ETO fusion transcripts identical to those round in c lassical t(8:21). The present case highlights the relevant role of the rear ranged chromosome 8. which encodes the AML1;ETO fusion product in the patho genesis of AML-M2. (C) 2001 Elsevier Science Inc. All rights reserved.