The bone marrow karyotype in seventeen cases of refractory anemia with excess of blasts (RAEB).

The bone marrow karyotype was studied in 17 patients affected by refractory anemia with excess of blasts (RAEB). A cytogenetic finding common to nearly all the cases is hypodiploidy, present in even quite high percentages. In 3 patients were identified the same interstitial deletion of the long arm of a chromosome 5, present in a percentage varying between 30% and 65%. The presence of this chromosomal anomaly appears to correspond to a slower development of the illness and transformation into acute leukemia seems rare or delayed.