Toxic gain of function mutations in the gene LRRK2 coding for dardarin, loss of protective function mutations in the genes PRKN, PINK1, and DJ-1, as well as substitution mutations affecting the SNCA gene coding for α-synuclein, have all been implicated in the pathogenesis of PD [11,12,13,14,15]. This evidence concerns the gene LRRK2 and Parkinson disease.