Additionally, non-coding polymorphisms close to the LRRK2 locus act as risk factors for sporadic disease [48] Furthermore, LRRK2 interacts with the protein products of at least two GWAS hits, RAB7L1 and GAK, linking PD-related genes with monogenic and complex forms [49, 50]. The gene discussed is LRRK2; the disease is Parkinson disease.