LRRK2 and inborn mitochondrial metabolism disorder: Many of the genes associated with familial PD also implicate mitochondria during disease pathogenesis such as DJ-1, PINK1, leucine-rich repeat kinase 2 (LRRK2); therefore, PD is described as a mitochondrial disease of aging, as mutations in DJ-1, PINK1, and LRRK2 genes are involved in mitophagy that affects mitochondrial quality control in PD [2].