Spontaneous SCE levels in cells with mutated ADH5 and ALDH2. (A) Mean ± standard deviation (SD) of spontaneous SCEs in PHA-blasts and fibroblasts from ADH5/ALDH2-deficient patients and controls. Each point represents the mean number of SCE events per cell in a single individual. Levels of SCEs from 3 patients with ADH5/ALDH2 deficiency (P1 [AP39P], P2 [AP57P], and P3 [FA50P]),²  healthy control fibroblasts or PHA-blasts, and patients with AA (negative control) or Bloom syndrome (BS2CH, positive control) were obtained from data deposited in the JCRB Cell Bank. The data are presented in bar graphs in supplemental Figure 1. The SCE data from PHA-blasts of P1 and P2 were described previously.²  (B) Mean ± SD of SCE events per cell (n = 30) induced by ADH5 inhibitor in PHA-blasts from 6 healthy individuals with the indicated ALDH2 genotypes. The P values were calculated using 1-way ANOVA with Tukey’s multiple-comparisons test. Right panels show the representative images of SCE with or without ADH5 inhibitor. Red arrowheads indicate the sites of chromatid exchanges. The SCE data without ADH5 inhibitor in 2 G/A individuals were described previously.²  (C) Schematic diagram of the spontaneous SCE levels in lymphocytes (PHA-blasts) and fibroblasts. HCHO, formaldehyde.