The clinical genetics of leucine-rich repeat protein kinase-2 (LRRK2) can be traced back to 1978, when researchers described a family in the Sagamihara City, Japan, in which at least 5 generations were afflicted with autosomal dominant inherited Parkinson's disease (PD), resembling idiopathic disease with age of onset typically after 50 years [1]. This evidence concerns the gene LRRK2 and Parkinson disease.