Table 2

NQO1 nt 609 polymorphism in subgroups of pediatric leukemia

CategorynNQO1 609aNQO1 609 T allele freq.Low NQO1c OR (CI)P
MLL+ totale36161730.322.54 (1.08–5.96)0.015
MLL/AF4 subset2141520.458.63 (2.45–33.22)f<0.0001f
TEL-AML1 + 50282010.221.52 (0.71–3.25)0.16
Hyperdiploid2920900.160.91 (0.33–2.38)0.52
  • a bp corresponding to the major functional NQO1 polymorphism.

  • b CC, homozygous functional allele; CT, heterozygous allele; TT, homozygous nonfunctional allele.

  • c Low NQO1 is defined as homozygous variant or heterozygous at the nt 609 polymorphism. ORs compare the ratio of low NQO1 patients in each category to controls.

  • d Reference group.

  • e All of the cases with MLL gene rearranged (i.e., with AF4, AF9, or ENL partners).

  • f We have considered the possibility that these elevated risks may be an artifact of including patients studied only in remission, i.e., some impact of NQO1 alleles on clinical response rather than incidence of disease. Although we cannot rule out some effect of selection, it is unlikely to explain our results. A total of 85–95% of patients with MLL gene fusions do enter remission on current therapeutic protocols, although some 50% may relapse by 12 months (59) . Our remission samples were collected after the achievement of remission and generally within 3 months. In the case of the critical subset of patients with MLL/AF4 fusions, 12 were genotyped at diagnosis and 9 in remission and for the diagnosis samples only. The elevated OR holds for both: 4.06 (CI, 1.006–17.5; P = 0.029).