Interestingly, there appear to be population-specific variants in LRRK2; for example, the G2019S variant is prevalent among the Ashkenazi Jews and North African Arabs (occurring in approximately 20% and 40% of PD patients in these groups, respectively [5]) but is absent in Asian populations (Chinese, Indian, Korean, and Japanese) [6, 7]. The gene discussed is LRRK2; the disease is Parkinson disease.