The strategy of allotopic expression as a roundabout route for GT of MD was proposed in 2002 by G. Manfredi et al. [140] to treat 8993 T– > G mutation of mtDNA MTATP6 gene causing impaired mitochondrial ATP synthesis in two related MD: neuropathy, ataxia, and retinitis pigmentosa and maternally inherited Leigh syndrome. This evidence concerns the gene MT-ATP6 and Menkes disease.