In the SNCA gene, point mutations as well as duplication and triplication of that locus cause highly penetrant early onset PD with varying pathology and clinical features among patients (Polymeropoulos et al., 1997; Krüger et al., 1998; Singleton et al., 2003; Zarranz et al., 2004; Proukakis et al., 2013). Here, SNCA is linked to Parkinson disease.