Genetic linkage studies of Parkinson's disease (PD) have identified a number of genes which include SNCA (PARK1) (Polymeropoulos et al. 1997), Parkin (PARK2) (Kitada et al. 1998), PTEN-induced putative kinase (PINK1; PARK6) (Valente et al. 2004), DJ-1 (PARK7) (Bonifati et al. 2003b) and leucine rich repeat kinase 2 (LRRK2; PARK8) (Paisan-Ruiz et al. 2004), ATP13A2 (PARK9) (Ramirez et al. 2006), PLA2G6 (PARK14) (Paisan-Ruiz et al. 2009), FBXO7 (PARK15) (Fonzo et al. 2009), and VPS35 (PARK17) (Vilariño-Güell et al. 2011; Zimprich et al. 2011). The gene discussed is LRRK2; the disease is Parkinson disease.