Mutations in "SCO2" that alter the regulation of copper and oxygen have been found to be associated with fatal infantile Cardioencephalomyopathy due to cytochrome c oxidase deficiency 1 (CEMCOX1), Myopia 6 (MYP6), and Leigh syndrome (LS). CEMCOX1 is characterized by disorders characterized by hypotonia, developmental delay, hypertrophic cardiomyopathy, lactic acidosis, gliosis, neuronal loss in basal ganglia, brainstem and spinal cord, and cytochrome c oxidase deficiency. Myopia 6 is characterized by a refractive error of the eye, in which parallel rays from a distant object come to focus in front of the retina, vision being better for near objects than for far. Lastly, leigh syndrome is an early-onset progressive neurodegenerative disorder characterized by the presence of focal, bilateral lesions in one or more areas of the central nervous system including the brainstem, thalamus, basal ganglia, cerebellum and spinal cord. Clinical manifestations may include psychomotor retardation, hypotonia, ataxia, weakness, vision loss, eye movement abnormalities, seizures, and dysphagia. A pathogenic mutation of G1541A in a patient has shown strong evidence in neonatal hypotonia with an SMA 1 phenotype, and has been found to result in less COX deficiencies. A mutation of 1602T>G has been found to result in rapidly progressive disease phenotypes. Other pathogenic mutations have included a missense mutation of E140K, a nonsense mutation Q53X, and a 1541G > A mutation which resulted in a severe protein instability. In addition to co-complex interactions, SCO2 has been found to interact with COA6, THEM177 in a COX20-dependent manner, COX20, COX16, SCO1, and others.