Trisomy 13 in acute leukemia.

Trisomy 13 occurring as a sole cytogenetic abnormality has recently been demonstrated to have adverse prognostic significance in acute leukemia. Trisomy 13 is seen primarily in an older male population, and has been reported in treatment-associated acute leukemia and acute leukemia evolved from myelodysplastic syndromes, as well as in de novo leukemia. The 36 cases of acute leukemia with trisomy 13 reported to date include 26 AML, 6 AUL, 2 ALL and 2 mixed lineage patients. Immunophenotyping studies have demonstrated an undifferentiated phenotype or biphenotypic markers in most cases. Trisomy 13 is associated with a low complete remission rate and with brief remission duration. The role of the additional copy of chromosome 13 in the pathogenesis of these cases of acute leukemia and the gene(s) of importance on chromosome 13 are yet to be determined.