Antioxidant polymorphisms do not influence the risk of epilepsy or its drug resistance after neonatal hypoxic-ischemic brain injury

PURPOSE The aim of this study was to investigate if common functional antioxidant polymorphisms are associated with epilepsy after neonatal hypoxic-ischemic encephalopathy (HIE). The antioxidant enzymes manganese superoxide dismutase (SOD2), glutathione peroxidase 1 (GPX1) and catalase (CAT) represent the primary defence mechanism against reactive oxygen species (ROS). Evidence suggests that genetic variants in antioxidant enzymes could influence susceptibility to epilepsy, but to date the relationship between them remains unclear. METHODS The study comprised 214 patients with epilepsy (64 with and 150 without neonatal HIE) as well as 95 healthy controls. Genomic DNA was isolated from buccal swabs or venous blood samples and genotyped for SOD2 rs4880, GPX1 rs1050450 and CAT rs1001179 using real-time PCR-based methods. RESULTS The investigated polymorphisms influenced neither the overall risk of epilepsy nor the risk of epilepsy after HIE in comparison with healthy controls. Furthermore, no significant difference in genotype distribution was observed between patients with drug-resistant epilepsy and patients in remission in either the group with epilepsy but without HIE or in the group with epilepsy and HIE, although the frequency of drug-resistant cases was higher in the latter group (p=0.009, OR=2.52; 95% CI=1.22-4.15). CONCLUSION According to this study, common GPX1, SOD2 and CAT polymorphisms do not influence the overall risk of epilepsy after HIE and its drug resistance.