Karyotypic Abnormalities in Secondary Leukemia of Children

Over a period of 10 years the bone marrow of 38 children with secondary leukemia was cytogenetically analyzed. After comparison of all karyotypes, chromosomes 5, 7, and 11 were found to be most frequently involved in numerical or structural aberrations. Whereas in ANLL chromosomes 5 and 7 predominated, chromosome 11 was found in all groups, but mainly in ALL. The breakpoints of different rearrangements were always located in band 11q23.