A common polymorphism in SNCA is associated with accelerated motor decline in GBA-Parkinson's disease. Issue 6 (2nd April 2020) - Stoker, Thomas B; Camacho, Marta; Winder-Rhodes, Sophie; Liu, Ganqiang; Scherzer, Clemens R; Foltynie, Thomas; Barker, Roger A; Williams-Gray, Caroline H