SNCA and Parkinson disease: Intriguingly, some pleomorphic risk loci overlap with the known causative genes of monogenic PD, such as SNCA, glucosylceramidase beta (GBA), leucine rich repeat kinase 2 (LRRK2), and vacuolar protein sorting 13 homolog C (VPS13C) (Singleton and Hardy, 2011; Nalls et al., 2019; Blauwendraat et al., 2020).