Conventional and molecular cytogenetic findings of myelodysplastic syndrome patients.

Myelodysplastic syndrome (MDS) involves myeloid cells of the bone marrow, which is important in progressive bone marrow insufficiency. Of all MDS patients, 40%-50% have at least one chromosomal rearrangement. Loss of specific chromosomal regions like 5q- and 7q- are usually the secondary cytogenetic abnormalities associated with MDS. In order to detect chromosome abnormalities associated with MDS, bone marrow samples from 26 patients diagnosed as MDS were obtained prior to chemotherapy. Both conventional cytogenetic analyses and fluorescence in situ hybridisation (FISH) methods were performed and locus-specific probes for 5q and 7q were used. Results obtained were compared. Twenty-one patients had normal karyotypes and four patients had abnormal karyotypes, while in one patient we could not obtain metaphases from cultures. Three patients with normal karyotypes revealed del (5q), two patients had del (7q) and one patient had monosomy (7). A total of 10 of 26 patients had chromosome changes visualised by either conventional or molecular cytogenetics (approximately 38.5%). Our results show that both methods are important in diagnosis and follow up of MDS patients. When used together, conventional cytogenetics and FISH detect clinically significant chromosome abnormalities in MDS patients.