Various genes are implicated as monogenic causes of PD, or, for disorders with Parkinsonism, among the former, mutations in SNCA (or PARK1) and LRRK2 (or PARK8) are associated with the autosomal dominant inheritance of PD, while mutations in PRKN (or PARK2), PINK1 (or PARK6) and DJ-1 (or PARK7) [16] are responsible for the forms inherited in an autosomal recessive manner. Here, LRRK2 is linked to Parkinson disease.