The impacts of prominent gene polymorphisms in DNA repair enzymes on Parkinson's disease.

Parkinson's Disease (PD), a chronic and progressive neurodegenerative disease of the brain, is associated with the loss of dopaminergic neurons. Its pathogenesis remains unclear; however, oxidative DNA damage due to reactive oxygen species (ROS) is believed to play a major role in the etiology of PD. DNA repair systems can mitigate oxidative DNA damage and help to maintain genomic stability and thus prevent neuronal death. However, gene polymorphisms on DNA repair enzymes may alter the functions of enzymes and increase the risk of PD. The present study aims to investigate a possible link between the OGG1, XRCC1, and MTH1 gene polymorphisms and PD risk in 97 patients with PD and 102 controls in the Turkish population. Our genotyping study utilizing polymerase chain reaction-restriction fragment length polymorphism revealed no relationship between two gene polymorphisms (OGG1Ser326Cys and MTH1Val83Met) and PD risk. Participants with the XRCC1 variant genotypes had a two to three and a half fold higher risk of PD than controls (p = 0.046, OR = 1.910, 95 % CI= [1.013-3.603] and p = 0.006, OR = 3.742, 95 % CI= [1.470-9.525], respectively). Our results suggested that XRCC1 Arg399Gln polymorphism is a risk factor for PD.