GBA1 and Parkinson disease: The ROPAD study pilot findings from 1288 initially recruited patients resulted in ∼13% study participants with a positive PDGT attributable to GBA1 (∼9%), LRRK2 (∼3%) and PRKN (∼1%) variants.10 Analysis of the complete ROPAD data set revealed an even greater positive PDGT yield, indicating that in ∼15% of patients, PD has a genetic contribution that is mostly conferred by variants in GBA1 (∼10%), LRRK2 (∼3%) or PRKN (∼1%).