GBA1 and Parkinson disease: Familial PD is affected by mutations in genes such as Parkin (PRKN), glucocerebrosidase (GBA1), leucine-rich repeat kinase 2 (LRRK2), vacuolar protein sorting-associated protein 35 (VPS35), PTEN-induced putative kinase 1 (PINK1), and F-box only protein 7 (FBXO7).