The main pathogenic genes of PD comprise α-synuclein, leucine-rich repeat kinase 2 (LRRK2), phosphatase and tensin homologue (PTEN)-induced putative kinase 1, parkin RBR E3 ubiquitin protein ligase (PRKN), DJ-1 (Parkinsonism associated deglycase, PARK7), glucosylceramidase (GBA), and vacuolar protein sorting-35 (VPS35) [197]. The gene discussed is GBA1; the disease is Parkinson disease.