A near-significant reduction in XPC protein expression (p = 0.058) was detected in lymphoblastoid cell lines homozygous for these alleles but no differences in mRNA stability in these lines was found or in mRNA or protein levels in lymphocytes heterozygous for these alleles.
However, when we examined the impact of these variants on endogenous mRNA and protein levels in a small panel of LCLs homozygous for the wildtype or variant alleles whilst we found a borderline significant, approximately 30%, reduction in XPC protein expression, the mRNA expression result was more difficult to interpret as, although there was a lower mean mRNA level in homozygous carriers, there was a wide interquartile range and the result was not statistically significant.