Several MAPT loci variants have already been reported to interact with the LRRK2 gene [55] and might increase the susceptibility to PD, such as MAPT IVS1 + 124 C > G variant that seems to modify the PD risk in LRRK2 p.G2385R carriers in East Asians, as well as slightly decrease the age of onset [56]. The gene discussed is MAPT; the disease is Parkinson disease.