LRRK2 and Parkinson disease: More than 30 different causative genes for familial PD have been reported, including dominant types of PD caused by variants in synuclein alpha (SNCA) and leucine rich repeat kinase 2 (LRRK2), and recessive types caused by variants in parkin RBR E3 ubiquitin protein ligase (PRKN), PTEN induced kinase 1 (PINK1), and Parkinsonism associated deglycase (PARK7, or DJ-1) [2].