SNCA and Parkinson disease: Molecular genetic studies have identified thirteen genes linked to rare dominant or recessive monogenic forms of PD: SNCA, Parkin, PINK1, DJ-1, LRRK2, ATP13A2, VPS35, PLA2G6, FBXO7, EIF4G1, SYNJ1, DNAJC6, and DNAJC13[2], [3].