LRRK2 and Parkinson disease: The mean age of PD diagnosis for dual carriers was 60.1 years (SEM = 1.6 years), 61.4 (SEM = 0.5) for LRRK2 p.G2019S, 59.1 (SEM = 0.5) for GBA1 p.N409S, and 61.5 (SEM = 0.1) for noncarriers.