Only a small percentage of PD patients (4–16%) are associated with genetic mutations, including leucine rich repeat kinase 2 (LRRK2 PARK8), Parkin (PARK2), synuclein alpha (SNCA, PARK1-4), Parkinsonism associated deglycase (DJ-1, PARK7), and phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1, PARK6) [124,125]. The gene discussed is LRRK2; the disease is Parkinson disease.