Mutations in a number of genes including SNCA, LRRK2, VPS35, DJ-1, GBA, PRKN and PINK1 have been linked to inherited forms of PD, accounting for ~10% of cases, while genome-wide association studies (GWAS) have identified more than 90 risk loci for sporadic PD [2]. Here, LRRK2 is linked to Parkinson disease.