Complex chromosomal abnormalities in acute nonlymphocytic leukemia

A comparison of chromosome abnormalities between 31 cases of de novo acute nonlymphocytic leukemia (ANLL) with complex karyotypes and 30 cases of secondary ANLL or dysmyelopoietic syndromes (DMS) revealed significant differences. Hyperdiploidy and partial or complete monosomy 5 were more frequent in complex de novo ANLL, whereas, hypo or pseudodiploidy and partial or complete monosomy of chromosome #7 were more frequent in secondary ANLL/DMS. Monosomy 17 and partial deletion of the short arm of chromosome #12 (12p-) occurred more commonly in de novo ANLL and secondary ANLL/DMS, respectively, but were not statistically significant. Therefore, although the abnormalities found in the two groups were of the same basic type, the frequencies of occurrence differed. These findings suggest the role of as yet unknown agents in the etiology of some so called de novo ANLL, and that different mutagenic or carcinogenic agents may produce different chromosomal abnormalities.