A chromosome study on 97 cases of acute nonlymphocytic leukemia M2.

Chromosomal studies were performed in the same laboratory on 97 untreated cases of de novo acute nonlymphocytic leukemia M2. The overall incidence of chromosomal abnormality was 70.1% (68 out of 97 cases), which was higher in children (84.2%) than in adults (61%). The male to female chromosomal abnormality ratio was nearly the same (male 71% and female 68.4%, P > 0.05). Hypodiploidy was the most common numerical abnormality (39%) and t (8; 21) was the most common structural abnormality (48.1%). In the patients with t(8; 21), 64.5% (20 out of 31 cases) male lost chromosome Y (-Y) and 33% (5 out of 15 cases) female lost one chromosome X (-X).