SNCA and Parkinson disease: Several missense mutations altering physico-chemical properties of α-synuclein as well as increased production of α-synuclein caused by duplications and triplications of the genomic region containing encoding gene, SNCA, have been associated with the development of familial forms of Parkinson’s disease (PD) and related disorders (Polymeropoulos et al. 1997; Kruger et al. 1998; Singleton et al. 2003; Zarranz et al. 2004; Chartier-Harlin et al. 2004; Ibanez et al. 2004; Proukakis et al. 2013; Appel-Cresswell et al. 2013; Kiely et al. 2013; Lesage et al. 2013).