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 unusual rearrangement between chromosomes 9 and 17. leading to a dicentric chromosome with an insertion of material of unknown origin between both chromosomes. By fluorescence in situ hybridization (FISH), the insertion was shown to be an amplification of part of 17q. involving ERBB2, RARA. and TOP2A genes. The median copy number of ERBB2, RARA. and TOP2A genes in the tumor cells was six (range: 4-10). Only one copy of the MPO gene at 17q21.3 was detected, 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.