Reduced expression of BER genes in DS patient samples. RNA was isolated and reverse transcribed from blast cells obtained from DS and non-DS (nonDS) patients as described in “Clinical TMD and AMkL samples.” Median gene expression levels were determined by quantitative real-time RT-PCR and normalized to 18S expression. (A) UDG expression. DS TMD vs non-DS AMkL, P < .01; DS AMkL vs non-DS AMkL, P = .1. (B) DNA polymerase β expression. DS TMD vs non-DS AMkL, P = .02; DS AMkL vs non-DS AMkL, P = .07. DNA polymerase β expression in 1 DS AMkL patient sample fell below the level of detection and was excluded from analysis.