LRRK2 and Parkinson disease: In the last two decades, at least 18 chromosomal loci (PARK1-18) have been assigned to PD through classic linkage analysis or genome-wide association studies[5], and eight genes (SNCA, LRRK2, Parkin, PINK1, DJ-1, ATP13A2, VPS35 and EIF4G1) have been linked to autosomal PD[6].