SNCA and Parkinson disease: More than 20 PD-related genes have been identified, including SNCA, leucine-rich repeat kinase 2 (LRRK2), glucocerebrosidase (GBA), PINK1, DJ-1 and Parkin (Li et al., 2014; Kalinderi et al., 2016; Balestrino and Schapira, 2018).