LRRK2 and Parkinson disease: Even though the most frequent types of PD are idiopathic in nature (Cannon and Greenamyre, 2011; Giordano et al., 2012), around 10% of familial cases are caused by mutations in “PARK” genes: e.g., PARK1/4/SNCA, PARK2/PARKIN, PARK6/PINK1 and PARK7/DJ-1, and PARK8/LRRK2 (Polymeropoulos et al., 1997; Lücking et al., 2000; Abou-Sleiman et al., 2003; Paisán-Ruíz et al., 2004; Valente et al., 2004).