Cytogenetic studies in 69 patients with myelodysplastic syndromes (MDS).

Cytogenetic studies were performed in 69 patients with myelodysplastic syndromes classified according to the FAB proposals. Overall incidence of chromosomal anomalies was 48% with 5q-, +8, 12p-,-7/7q- being the aberrations most often found. The 12p- chromosome showed a close correlation with a prior exposure to mutagenic agents and CMML. Although there were no group-specific cytogenetic anomalies, FAB classification strongly influenced their incidence. They were lower (36%) in RA/RA-S than in RAEB/RAEB-T/CMML (53%). Chromosomal anomalies were significantly more often found in patients with a prior exposure to carcinogenic agents (80%) than in unexposed patients (33%). The presence of chromosomal anomalies did not predict a higher risk of leukemic transformation.