Mutations in at least six genes were shown to cause familial parkinsonism: mutations in SNCA and LRRK2 account for autosomal dominant forms of PD, whereas mutations in parkin, PINK1, DJ-1 and ATP13A2 (Ramirez et al. 2006) show a recessive mode of inheritance (mutations in the latter are characteristic of Kufor-Rakeb syndrome, and will not be further discussed). Here, LRRK2 is linked to Parkinson disease.