Some of the genes that are considered to be diagnostically important are α-synuclein (SNCA), PINK1, leucine-rich repeat kinase 2 (LRRK2), and β-glucocerebrosidase (GBA), and analysis for identifying mutations in them as diagnostics is still undergoing considerable study since they account for almost 2-3% of Parkinson’s patients [28]. This evidence concerns the gene SNCA and Parkinson disease.