LRRK2 and Parkinson disease: LRRK2 mutations have been identified in up to 13% of familial PD cases (Paisán-Ruíz et al., 2004; Zimprich et al., 2004) and also account for 1%–2% of not familial cases (Aasly et al., 2005; Goldwurm et al., 2005).