The most common gene variants in PD include mutations in synuclein alpha (SNCA), parkin RBR E3 ubiquitin-protein ligase (PRKN), protein deglycase-1(DJ-1), PTEN induced kinase 1 (PINK1), leucine-rich repeat kinase 2 (LRRK2), and vacuolar protein sorting ortholog 35 (VPS35), which all play a role in neuroinflammation, aberrations in synaptic transmission, neuronal cell degradation, and cognitive decline [27,28]. Here, LRRK2 is linked to Parkinson disease.