cytochrome-c oxidase deficiency, a hereditary defect in the cytochrome-c oxidase complex that prevents the transfer of electrons from cytochrome c to molecular oxygen, ultimately halting adenosine triphosphate production. Manifestations are extremely variable and include myopathies, encephalopathies, ocular and cardiac defects, sensorineural deafness, Fanconi syndrome, diabetes mellitus, and short stature. Inheritance may be autosomal recessive, X-linked, or, possibly, maternal (mitochondrial), depending on the part of the cytochrome-c oxidase complex that is affected.
