XPD gene rs13181 polymorphism and DNA damage in human lymphocytes.

Genetic heterogeneity influencing enzyme activity may change the capacity to repair DNA damage induced by environmental and endogenous factors. This study aims to assess the impact of Lys751Gln (A/C) polymorphism in the XPD gene, encoding an enzyme involved in the nucleotide excision repair pathway, on individual DNA damage. The DNA damage in human lymphocytes (% DNA in the tail) was quantified by means of single-cell gel electrophoresis. Baseline levels of DNA damage significantly differ between AA homozygotes and carriers of the C allele, and the observed differences were not related to age, gender, or smoking status. It seems that the AA variant is associated with enhanced protection against oxidative DNA damage.