GBA1 and Parkinson disease: Roughly 15% of PD cases are familial, most being inherited due to high penetrance mutations in 7 different well-established PD genes: SNCA (encoding α-Synuclein), PRKN (encoding Parkin), PINK1 (encoding PTEN-induced putative kinase protein 1), PARK7 (encoding DJ-1), GBA1 (encoding Beta-glucosylceramidase 1), LRRK2 (encoding Leucine-rich repeat kinase 2), and VPS35 (encoding Vacuolar protein sorting-associated protein 35; Lim and Klein, 2024; Bandres-Ciga et al., 2020).