Mutations in several genes are each associated with the occurrence of PD, including alpha synuclein (SNCA), leucine-rich repeat kinase 2 (LRRK2), and other autosomal recessive mutations in genes such as Parkin (PARK2), PTEN-induced putative kinase 1 (PINK1) and Protein/nucleic acid deglycase DJ-1 (PARK7), and has been extensively reviewed in Klein and Westenberger (2012). This evidence concerns the gene SNCA and Parkinson disease.