Mutations in several PD causing genes, encoding PINK1 (PTEN-induced serine/threonine kinase 1), Parkin, α-synuclein, LRRK2 (leucine-rich repeat kinase 2), DJ1, CHCHD2 (coiled-coil-helix-coiled-coil-helix domain-containing 2), and POLG (mitochondrial DNA polymerase gamma), have been shown to induce mitochondrial dysfunction demonstrating that mitochondrial homeostasis and quality control have a central role in the disease process [4–14]. This evidence concerns the gene POLG and Parkinson disease.