Facial anomalies in patients with cytochrome-c-oxidase (COX) deficiency: a dysneurulation.

The authors report 3 cases of cytochrome-c-oxidase deficiency (2 cases of Kearns-Sayre syndrome and 1 case of chronic progressive external ophthalmoplegia) with Central Nervous System alterations and facial anomalies. The facial anomalies are high forehead, wide nasal bridge, upturned nose, long and flat philtrum (alterations depending on frontal-nasal-premaxillary structures which derive from prosencephalic neural crests), hypoplastic maxilla and mandible, ophthalmoplegia (alterations of maxilla and III-VI cranial nerve nuclei, which derive on the mesencefalic neural crests), low set ears, short neck (alterations of the 3rd, 4th branchial arch derivatives, which arise from rhombencephalic neural crests). The authors conclude that cytochrome-c-oxidase deficiency in embryonic stage can injure, in Kearns-Sayre syndrome and chronic progressive external ophthalmoplegia, distal tissues of face and Central Nervous System depending on neural crests, and that the symptomatology of these diseases can be ascribed to dysneurulation.