The AD form of PD is associated with alterations of the α-synuclein (SNCA) and leucine rich repeat kinase 2 (LRRK2) genes (Bekris et al., 2010; Klein and Westenberger, 2012) whereas the Parkin RBR E3 ubiquitin protein ligase (PRKN), Parkinsonism associated deglycase (PARK7), PTEN induced putative kinase 1 (PINK1) and ATPase 13A2 (ATP13A2) genes are linked to the AR form of PD (Nuytemans et al., 2010; Heman-Ackah et al., 2013). Here, LRRK2 is linked to Alzheimer disease.