LRRK2 and Parkinson disease: Mutations in GBA, LRRK2, PARK2, PARK7 (DJ-1), PINK1,α-Synuclein (SNCA), or UCHL1 can lead to monogenic forms of PD or increased PD susceptibility, suggesting important roles for these proteins in the pathogenesis of the disease [43]. SNCA is the first gene linked to autosomal-dominant familial PD, which encodes a synaptic vesicle-associated protein that appears in high abundance in Lewy bodies [44].