LRRK2 and Parkinson disease: In 2004, point mutations in the Leucine-rich repeat kinase 2 (LRRK2) gene were discovered by two groups simultaneously (Paisán-Ruíz et al., 2004, Zimprich et al., 2004) and subsequently, LRRK2 mutations have been linked to 5–8% of familial (Nichols et al., 2005) and 1–2% of sporadic PD cases (Gilks et al., 2005).