LRRK2 and Parkinson disease: Genetic linkage studies have linked gene PTEN induced putative kinase 1 (PINK1) and PARK2 to Parkinson’s disease (Wang et al., 2011) while both the genetic linkage studies (Paisan-Ruiz et al., 2006) and genome wide association studies (GWAS; Simon-Sanchez et al., 2009) have identified leucine-rich repeat kinase 2 (LRRK2) to be genetically linked and associated with the disease.