Precise Delination of 5q-Breakpoints and Detection of Hidden Aberrations in patients with MDS using Array CGH

ABSTRACT: Isolated deletions of the long arm of chromosome 5 (del(5q)) are observed in 10% of myelodysplastic syndromes (MDS) and are associated with a more favorable prognosis, although the clinical course varies considerably. If one or more additional chromosomal aberration/s are present this correlates with a significant shorter overall survival. To assess the frequency of hidden abnormalities in cases with an isolated cytogenetic del(5q), we have performed a genome wide high resolution 44K 60mer oligonucleotide array CGH study using DNA from bone marrow cells of 12 MDS and one AML patient. Additional chromosomal aberrations were identified in three of 13 cases (23%): in one case, a single additional hidden 5.6 Mb deletion of 13q14 and in two cases, multiple larger aberrations involving many chromosomes. Fluorescence in situ hybridization (FISH) demonstrated that aberrations present in only 10% of the bone marrow cells were detectable by aCGH. Furthermore with oligonucleotide aCGH the deletion end points in 5q were mapped precisely, revealing a cluster of proximal break points in band q14.3 (n=8) and a distal cluster between bands q33.2 to q34 (n=11). This study shows the high resolution of oligonucleotide CGH arrays for precisely mapping genomic alterations and for refinement of deletion end points. In addition the high sensitivity of this method enables the study of whole bone marrow cells from MDS patients, a disease with a low blast count. Future studies of more patients with isolated del(5q) for hidden abnormalities will be necessary to evaluate the impact of these on the variable prognosis in these patients and to further define new genetic subgroups. Keywords: Myelodysplastic syndromes, MDS, array CGH, del(5q), hidden aberrations

ORGANISM(S): Homo sapiens

PROVIDER: GSE8804 | GEO | 2007/09/11

SECONDARY ACCESSION(S): PRJNA102113

REPOSITORIES: GEO