Garrido and co-workers [109] applied the protocol originally proposed by Fairfoul [104] and used in other studies [110, 111] to assess the presence of α-synuclein aggregation competent species in the CSF derived from α-synucleinopathies patients carrying a genetic PD mutation in the gene coding for leucine -rich repeat kinase 2 (LRRK2). This evidence concerns the gene LRRK2 and Parkinson disease.