GBA1 and Parkinson disease: We have reviewed data regarding all genetic PD patients at enrollment (n = 791), collected all SNCA A53T mutation carriers (n = 42) and removed all GBA (n = 303), LRRK2 (n = 428), PRKN (n = 14), PINK1 (n = 1) and simultaneous GBA/LRRK2 (n = 3) mutation carriers.