Amplification of ERBB2, RARA, and TOP2A genes in a myelodysplastic syndrome transforming to acute myeloid leukemia

zA patient is described with myelodysplastic syndrome (MDS) progressing to acute myeloid leukemia (AML) FAB MJ. Cytogenetic analysis revealed an unusu al rearrangement between chromosomes 9 and 17. leading to a dicentric chrom osome with an insertion of material of unknown origin between both chromoso mes. By fluorescence in situ hybridization (FISH), the insertion was shown to be an amplification of part of 17q. involving ERBB2, RARA. and TOP2A gen es. The median copy number of ERBB2, RARA. and TOP2A genes in the tumor cel ls was six (range: 4-10). Only one copy of the MPO gene at 17q21.3 was dete cted, suggesting a deletion of the telomeric part of 17q. To our knowledge, this is the first report of a 17q amplification in AML. (C) 2001 Elsevier Science Inc. All rights reserved.