Double-minute MYC amplification and deletion of MTAP, CDKN2A, CDKN2B, and ELAVL2 in an acute myeloid leukemia characterized by oligonucleotide-array comparative genomic hybridization

Abstract

Chromosomal analysis and fluorescence in situ hybridization (FISH) have been routinely used in detecting recurrent chromosomal abnormalities in patients with various hematological malignancies. However, the genomic imbalances underlying many recurrent abnormalities could not be delineated due to the low resolution of chromosome analysis. We have performed oligonucleotide-array comparative genomic hybridization (oaCGH) in an AML case with a 15p/17p translocation, a suspected 9p21 deletion, monosomies of chromosomes X and 9, and 2 to 60 double minutes. The oaCGH findings confirmed the chromosomal observations and further characterized a 21.338-Mb 17p deletion, a 3.916-Mb deletion at 9p21.3 containing the MTAP, CDKN2A, CDKN2B, and ELAVL2 genes, and a 3.981-Mb 8q24 double minute containing the TRIB1, FAM84B, MYC, and PVT1 genes, with an average of 30 double minutes in each cell. FISH using MYC probes and bacterial artificial chromosome clone probes confirmed the genomic findings and revealed a progressional pattern for the 9p21.3 deletion. These results demonstrate the potential of oaCGH as a powerful diagnostic tool for characterizing genomic imbalances for patients with hematological malignancies.