MTHFR and Parkinson disease: Their results identify eight SNPs as potential risk factors for PD in Mexican subjects (rs385705916, rs356220, rs356203, rs7684318, and rs2736990 in the SNCA gene, rs421016 in the GBA gene, rs35479735 in the NR4A2 gene, and rs1801133 in the MTHFR gene).