LRRK2 and Parkinson disease: In a small proportion of PD cases, genetic background has been identified, with β-Glucocerebrosidase (GBA), leucine-rich repeat kinase 2 (LRRK2), parkin (PRKN), protein/nucleic acid deglycase (DJ1) and phosphatase and tensin homologue (PTEN)-induced putative kinase 1 (PINK1) as the most common mutations [70].