Alpha-synuclein (non A4 component of amyloid precursor, SNCA, chr4q21-22, NM_000345.3, MIM #163890) was the first gene in which a causative mutation for Parkinson's disease (PD) was discovered in 1997 (Polymeropoulos et al., 1997; Nussbaum, 2017). This evidence concerns the gene SNCA and Parkinson disease.