Furthermore, the penetrance of PD among carriers of pathogenic variants in GBA1 is estimated at 10–30%, indicating that the majority of mutation carriers will never develop PD.20, 21, 22, 23 Thus, biomarkers that can prognosticate which GBA1 pathogenic variant carriers are more likely to develop PD are required to conduct patient‐enriched trials. Here, GBA1 is linked to Parkinson disease.