[Chromosome abnormalities and prognosis in childhood acute leukemia]

The chromosomal classification system of childhood acute leukemia according to ploidy or structural chromosomal changes of leukemia cells is clinically useful for the prediction of the treatment outcome. While patients with hyperdiploid (greater than 50 chromosomes) ALL enjoy the best prognosis, those with hypodiploid or pseudodiploid ALL are expected to have unfavorable clinical outcome. Among various translocations or deletions in ALL, t(4;11), t(9;22) and t(8;14) predict the worst clinical outcome. AML patients with t(8;21) or inv (16) have better 50% survival than those with other chromosome changes or normal diploidy. Chromosome analysis of leukemia cells should be included in the diagnostic workup of childhood acute leukemia.