Possible association between DNA repair gene variants and cannabis dependence in a Turkish cohort: a pilot study

OBJECTIVE: Substance use disorder (SUD) has important effects on health and well-being. It is well known that genetic factors play a role in SUD. The purpose of this research was to investigate whether functional variants of DNA repair genes might be a risk factor for cannabis and/or synthetic cannabis dependence in a Turkish cohort. METHODS: In total, 131 patients with cannabis and/or synthetic dependence and 70 healthy controls were included in this case–control study. XRCC1 codon 399 (rs25487) and XRCC4 G1394 T (rs6869366), and XPD (rs13181) variants were determined by the polymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP). RESULTS: The XRCC1 rs25487 GG genotype and G allele were significantly lower in patients compared to controls (p = 0.005; p = 0.002, respectively). XRCC4 rs6869366 TT genotype and T allele were more common in patients compared to controls (p = 0.001, p = 0.001, respectively). It was found that patients with XPD rs13181 Lys/Gln had a significantly higher risk of cannabis dependence than control did (p = 0.00). The subjects carried XPD rs13181 Gln/Gln genotype had a 2.2-fold increased risk for cannabis dependence (p = 0.010). CONCLUSIONS: We demonstrated for the first time that DNA repair gene variants may alter individual vulnerability for SUD. This observation could be of further interest to researchers, as it could suggest new candidate genes, presumably crucial for the etiopathogenesis of the cannabis and/or synthetic cannabis dependence.