LRRK2 and Parkinson disease: Prevalence of PD in G2019S carriers in the 23andMe population was 58.67% for subjects 50–60 years old and 42.86% for those 70–80 years comparing age-at-diagnosis in affected LRRK2 G2019S to age-at-survey for unaffected carriers in the PD Community and the broader 23andMe research database.