[Chromosome abnormalities in myelodysplastic syndrome].

We performed chromosomal analysis in 18 patients with myelodysplastic syndrome (MDS). According to the French-American-British (FAB) cooperative study group and Research Group of Japanese Ministry of Welfare Classification, our cases with MDS were classified into four subtypes as follows; refractory anemia [RA], 6 cases; refractory anemia with excess of blasts [RAEB], 4; chronic myelomonocytic leukemia [CMML], 3; refractory anemia with excess of blasts in transformation [RAEB-T], 4; and refractory cytopenia [RC], 1. Thirteen patients (72%) had chromosomal abnormalities and frequently observed chromosomal abnormalities were trisomy 8, -7/7q-, 20q-, trisomy 1q and 5q-. The mean survival were as follows; RA: 22.5 months, RAEB: 13.2 months, CMML: 15 months, RAEB-T: 5.5 months. Progression to overt leukemia occurred in 5 patients (27.7%): 1 of four patients with RAEB, 1 of three patients with CMML and 3 of four patients with RAEB-T. In conclusion, chromosomal abnormalities were most frequently observed in the patient with RAEB-T who had shortest survival time among the patients with MDS. On the other hand, chromosomal abnormalities were less frequently observed in the patients with RA and they showed relatively better prognosis than the other types of MDS.