NUDT1 and Parkinson disease: As mentioned earlier, Nakabeppu et al. were able to show a significant increase in 8-oxo-G in mtDNA as well as an elevation in expression of MTH1, OGG1, and MUTYH in nigrostriatal dopaminergic neurons of PD patients, suggesting that the accumulation of these lesions may be involved in the loss of dopaminergic neurons [44].