Karyotypic and clinical findings in a consecutive series of children with acute lymphocytic leukemia.

Detailed karyotypic findings and clinical data on 70 consecutive newly diagnosed children with acute lymphocytic leukemia (ALL), primarily from Indiana, are presented. These children fall into five karyotypic groups: (a) normal chromosomes; (b) hyperdiploid I, with chromosome numbers greater than 50, frequently with multiple copies of the same chromosome, and often lacking a consistent abnormal clone; (c) hyperdiploid II, with karyotypes having 47-49 chromosomes and usually with all of the karyotypically abnormal cells identical; (d) pseudodiploids, with either translocations or deletions of specific chromosomes; and (e) hypodiploids. Because few of this series of children have expired or relapsed, patients in the karyotypic groups have been considered in relation to those clinical factors that have been found to be of prognostic significance by the Children's Cancer Study Group. Age, white blood cell count, and platelet count were significantly different in patients among the five karyotypic groups. A significantly greater number of pseudodiploid patients had white blood cell counts greater than 50,000 X 10(6)/L and were not in the infant age group, as has been the case for other series. Specifically, the 4;11 translocation was associated with a higher risk of early death compared with other patients. Among those with normal karyotypes, platelet levels of greater than 100 X 10(9)/L occurred more frequently than among those with abnormal karyotypes.