SNCA and Parkinson disease: The first evidence showing that SNCA gene deregulation is directly associated with PD came from familial PD cases, where point mutations at the 53rd (alanine to threonine), 30th (alanine to proline), and the 46th (glutamine to lysine) amino acids were discovered, which led to an autosomal dominant form of disease inheritance along with early-onset (Polymeropoulos et al., 1997; Krüger et al., 1998; Zarranz et al., 2004).