Cytogenetic examination of 65 patients with primary MDS revealed cytogenetic changes in 39 (60%) of the patients. The most frequently affected chromosomes were chromosomes 5, 7, 11, 17 and 20. Deletion of 5q only found in 9 (23%) of the patients with chromosomal changes occurred similarly as simple chromosomal changes most frequently in the prognostically more favourable group MDS-RA. Prognostically adverse monosomy of chromosome 7 was found in 3 patients in group RAEB and RAEB-t but only as part of complex chromosomal changes. The latter were encountered most frequently in patients of groups RAEB and RAEB-t, similarly as trisomy of chromosome 8. Patients in these groups had also a significantly shorter survival time (RAEB 17.7 and RAEB-t 14.2 months) than patients in group MDS-RA (31.5 months). Evaluation of survival according to Kaplan-Meyer's curve revealed significantly longer survival of patients without cytogenetic changes. Laboratory, cytogenetic and clinical findings in four patients with CMML differed from findings of the remaining patients with MDS. This supports the view that this sub-group is rather a myoproliferative conditions than MDS. Transformation to AL was proved in 19 patients. 14 of them (74%) had a chromosomal change at the time of diagnosis.

Keywords: Adolescent; Adult; Aged; Aged, 80 and over; Chromosome Aberrations; Female; Humans; Karyotyping; Male; Middle Aged; Myelodysplastic Syndromes /genetics/; Prognosis