Around 90%of PD cases are not linked to any known cause, while the remaining10% have familial PD caused by mutations in specific genes like α-synuclein(SNCA), parkin RBR E3 ubiquitin protein ligase (PRKN), PTEN-induced kinase 1 (PINK1), andleucine-rich repeat kinase 2 (LRRK2)., This evidence concerns the gene SNCA and Parkinson disease.