[Cytogenetic study of 93 myelodysplastic syndromes]

We describe the cytogenetic results of 93 patients with myelodysplastic syndromes (MDS). The main object of this report is to analyze the prognostic value of the karyotype in patients with MDS, in relation to the evolution to acute leukemia and the survival time.

Cytogenetic studies were performed in 93 untreated cases of MDS between 1985 and 1994. Overall survival and the evolution to acute leukemia were analyzed.

Among 93 patients who were examined at the time of diagnosis, 40 had an abnormal karyotype (43%). The highest frequency of chromosome abnormalities was observed in refractory anaemia with excess of blasts (RAEB) (65.7%) and RAEB in transformation (RAEB-t) (40%) and the lowest in refractory anaemia with ringed sideroblasts (RARS) (10%). The chromosomes most frequently involved were: 5, 7, 8, 11, 12 and 17. No relationship was found between FAB subtypes and the type of chromosomal abnormalities. In respect to the prognosis, an abnormal karyotype, and a complex karyotype were related with a higher frequency of evolution to acute leukemia. A model based on karyotype could divide patients in two groups: poor prognosis (patients with an abnormal karyotype, with involvement of chromosome 7, trisomy 8 or with a complex karyotype), and a good prognosis (patients with normal karyotype).

The cytogenetic studies are very useful in the study of MDS for their clinical implications.