LRRK2 mutant variants show distinct topographical distributions, e.g., G2019S is predominant in familial PD patients in Caucasian populations [53] and Ashkenazi Jews (AJ) [54], whereas R1441C/G, I1371V, R1628P, and G2385R are more common among east Asian PD patients [55,56]. This evidence concerns the gene LRRK2 and Parkinson disease.