Studies involving patients with genetic mutations associated with familial PD have shown the presence of aSyn deposition in 100% of patients carrying SNCA mutations [215,227], 66.7–100% of PD carrying LRRK2 mutations [222,227], 60–83% of patients with GBA1 gene mutations [213,227], and 0% of patients with PRKN mutations [198,227]. The gene discussed is LRRK2; the disease is Parkinson disease.