The underlying genetic basis of PD is complex: a small proportion of PD cases are accounted for by monogenic forms of PD inherited in a Mendelian fashion (e.g., related to mutations in α-synuclein (SNCA), leucine-rich repeat kinase 2 (LRRK2), parkin, Parkinson’s disease-associated kinase-1 (PINK-1), DJ-1, ATP13A2), but numerous susceptibility genes and loci have also been identified (at least 24) (9), which contribute to the risk of idiopathic PD. This evidence concerns the gene PARK7 and Parkinson disease.