CUX1 inactivation impairs the DNA repair capacity of BM cells. BM mononuclear cells from patients and healthy subjects were maintained in 3% oxygen for 7 days, exposed to 10 µM (A) or 50 µM (B-D) H₂O₂ for 20 minutes and allowed to recover for the indicated time. Trypan blue staining was used to estimate cell viability and was: 9654 (87%), 9700 (86%), HD (82%), 6982 (78%), HD (88%), 4487 (92%), 6882 (90%), 8560 (78%), HD (88%), 8342 (75%), 8604 (82%), 11353 (73%). Cells were subjected to single-cell gel electrophoresis (comet assay) at pH 14, pH 10, and pH 10 in the presence of the FPG DNA glycosylase. Comet tail moments were scored for at least 50 cells per condition. The Student t test was used to compare groups. Error bars represent standard error. *P < .05, **P < .01, ***P < .001. HDs: 10972, 11353, 12393; (C-5 [38%], 9700 and C-80, 8342): frameshift mutation and UPD; C-77 (66%), 4487: frameshift mutation and microdeletion; C-10, 8604: deletion 7q, NGS3, 6882: UPD7; (C-29, 8560 and C-73, 6982 and 9654): diploid cases.