C-G translocation in acute myelocytic leukemia with low neutrophil alkaline phosphatase activity.

A consistent chromosome abnormality of C-G translocation, t(8;21)(q22;q22), was found in 15 acute myelocytic leukemia (AML) patients with low neutrophil alkaline phosphatase (N-AP) activity. Granulocytes of these patients also had specific morphologic abnormalities. The bone marrow showed a tendency to relatively good maturation of leukemic cells for the disease AML. Clinical courses of the patients were mild and median survival was longer than that of patients with normal or high N-AP activity (p = 0.065, suggestive difference). Three out of six male patients with these type of AML had missing Y chromosome in addition to C-G translocation. The results suggest that specific cytogenetic abnormality of C-G translocation would be significantly associated with AML. Contrasting with low N-AP activity and the Philadelphia chromosome in chronic myelocytic leukemia, the findings in AML may offer additional evidence towards the possible relations between alkaline phosphatase activity and C or G chromosome.