title: Sialidosis: the cherry-red spot--myoclonus syndrome.
abstract: The sialidoses are a group of storage disorders of autosomal recessive inheritance in which there is a deficiency of lysosomal neuraminidase (sialidase) activity and associated sialyloligosacchariduria. Patients with one type of sialidosis may present initially to the ophthalmologist because of a cherry-red spot at the macula. In most of these patients progressive neurologic deficits ultimately develop; myoclonus is a prominent feature. A patient with the so-called cherry-red spot--myoclonus syndrome is described who had a marked deficit of the ocular smooth pursuit system, with consequent nystagmus. His visual system was normal clinically and electrophysiologically despite the obvious storage in the retinal ganglion cells.
mesh_terms: D002648:Child; D004585:Electrooculography; D004596:Electroretinography; D006801:Humans; D008266:Macula Lutea; D008297:Male; D009207:Myoclonus / Q000150:complications*; D009439:Neuraminidase / Q000172:deficiency*; D009759:Nystagmus, Pathologic / Q000150:complications* / Q000175:diagnosis; D009844:Oligosaccharides / Q000652:urine; D012164:Retinal Diseases / Q000150:complications; D012438:Saccades; D012794:Sialic Acids / Q000652:urine; D013577:Syndrome
chemical_list: D009844:Oligosaccharides; D012794:Sialic Acids; D009439:Neuraminidase