The findings may have implications for the design of early interventional trials in LRRK2 G2019S carriers, including the need for more precise prodromal clinical criteria to detect early disease onset, using high PRS scores as an enrichment biomarker to optimize candidate selection for a high yield of phenoconverters, and developing more sensitive end points for tracking this slow progressing mild motor subtype of PD. This evidence concerns the gene LRRK2 and Parkinson disease.