title: Hyperammonemia-hyperornithinemia-homocitrullinuria syndrome: neurologic, ophthalmologic, and neuropsychologic examination of six patients.
abstract: We report the clinical, electrophysiologic, ophthalmologic, and neuropsychologic features of six patients with hyperammonemia-hyperornithinemia-homocitrullinuria syndrome, an inborn error of ornithine metabolism. Pyramidal signs, decreased vibration sense, bucco-facio-lingual dyspraxia, and learning difficulties or subnormal intelligence were found in the majority. Anomalies of peripheral nerve conduction velocity and of evoked potentials were common, and one patient had markedly abnormal white matter images on cranial magnetic resonance imaging. One patient had retinal depigmentation and chorioretinal thinning. The clinical severity varied greatly among patients; in general, the three younger patients had less neurologic and intellectual impairment than did the three older patients. Only two of our patients have had episodes of symptomatic hyperammonemia. We conclude that hyperammonemia-hyperornithinemia-homocitrullinuria syndrome can be associated with widespread manifestations in the central and peripheral nervous systems. Although the control of hyperammonemia is an essential element in the treatment of these patients, the relationship of hyperammonemia to the chronic neuropsychologic problems of these patients is unclear.
authors.affiliation: Department of Pediatrics, Radiology, Hôpital Sainte-Justine, Université de Montréal, Quebec, Canada.
authors.forename: J F
authors.initials: JF
authors.lastname: Lemay
authors.forename: M A
authors.initials: MA
authors.lastname: Lambert
authors.forename: G A
authors.initials: GA
authors.lastname: Mitchell
authors.forename: M
authors.initials: M
authors.lastname: Vanasse
authors.forename: D
authors.initials: D
authors.lastname: Valle
authors.forename: J F
authors.initials: JF
authors.lastname: Arbour
authors.forename: J
authors.initials: J
authors.lastname: Dubé
authors.forename: J
authors.initials: J
authors.lastname: Flessas
authors.forename: M
authors.initials: M
authors.lastname: Laberge
authors.forename: L
authors.initials: L
authors.lastname: Lafleur
mesh_terms: D000293:Adolescent; D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000150:complications / Q000175:diagnosis*; D000641:Ammonia / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D002956:Citrulline / Q000031:analogs & derivatives* / Q000652:urine; D005128:Eye Diseases / Q000150:complications* / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D009422:Nervous System Diseases / Q000150:complications* / Q000175:diagnosis; D009483:Neuropsychological Tests; D009952:Ornithine / Q000097:blood*; D011597:Psychomotor Performance
chemical_list: C001352:homocitrulline; D002956:Citrulline; D000641:Ammonia; D009952:Ornithine