Hyperdiploidy

In this issue of Blood, Dastugue and colleagues report their findings examining the impact of hyperdiploidy on the outcome of children with B-cell acute lymphoblastic leukemia (ALL). Since the 1980s, it has been appreciated that 25% to 30% of B-cell ALL cases have a “high” hyperdiploid karyotype (generally defined as >50-67 chromosomes) and that this subset has an unusually good prognosis (reviewed by Paulsson and Johansson).