Nakabeppu et al. showed a significant increase in 8-oxo-G in mtDNA as well as an elevated expression of 8-oxo-G dGTPase (MTH1), OGG1 and MutY glycosylase homologue (MUTYH) in nigrostriatal dopaminergic neurons of PD patients, suggesting that the buildup of oxidized DNA lesions may be involved in the loss of dopaminergic neurons [44]. This evidence concerns the gene OGG1 and Parkinson disease.