LRRK2 and Parkinson disease: LRRK2 parkinsonism can present with the same cardinal motor and nonmotor symptoms as sporadic PD [83] (we will refer to such patients and cohorts as LRRK2-PD), although the disease course and progression appear to be slightly more benign, as described in a recent meta-analysis of 66 clinical research studies evaluating the clinical phenotype of PD cases with p.G2019S, p.G2385R, p.R1628P, and p.R1441G LRRK2 mutations [84].