Chromosomes in acute leukemia.

The karyotype of leukemic cells of 78 acute leukemia patients (37 ANLL, 34ALL, and 7 of unknown type) was studied by means of G-banding. Chromosomal abnormalities were found in 50 patients (72%). Chromosomes 8,21,5,7,11, and 19 were preferentially involved in the abnormalities, both in ANLL and in ALL. A high incidence of the characteristic rearrangement t(8;21) was noted in AML: (in 6 of 22 AMP patients). An identical reciprocal translocation--t(4;11)--was seen in 4 out of 34 ALL patients.