SNCA and Parkinson disease: Genome-wide associated and case–control studies also linked α-synuclein to idiopathic and familial forms of PD as well as other synucleinopathies (Kay et al. 2008; Mizuta et al. 2008; Pankratz et al. 2009; Scholz et al. 2009; Sutherland et al. 2009).