Leigh syndrome is commonly associated with isolated cytochrome c oxidase (COX) deficiency due to mutations in several COX assembly factors, including SURF1, which encodes a biogenesis factor participating in the early steps of Complex IV maturation, the most common cause of COX-deficient Leigh syndrome (Smith et al., 2005; Bundschuh et al., 2009; Wedatilake et al., 2013). This evidence concerns the gene SURF1 and Leigh syndrome.