title: Downbeat nystagmus in two siblings with spinocerebellar ataxia type 6 (SCA 6).
abstract: We report two siblings with spinocerebellar ataxia type 6 (SCA 6), both showing downbeat nystagmus (DBN) as a predominant clinical feature. Familial hemiplegic migraine (FHM), episodic ataxia type 2 (EA-2) and SCA 6 are allelic disorders, and interestingly, the occasional presence of DBN in EA-2 was reported. Our observations suggest that common molecular mechanisms might underlie DBN in FHM, EA-2 and SCA 6. Then, these disorders should be kept in mind in diagnosing patients with DBN.
authors.affiliation: Department of Neurology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Harada
authors.forename: A
authors.initials: A
authors.lastname: Tamaoka
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Ishikawa
authors.forename: S
authors.initials: S
authors.lastname: Shoji
mesh_terms: D000328:Adult; D001284:Atrophy / Q000175:diagnosis; D015220:Calcium Channels / Q000235:genetics; D002531:Cerebellum / Q000473:pathology; D004247:DNA / Q000097:blood; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000150:complications* / Q000175:diagnosis / Q000235:genetics; D017422:Sequence Analysis, DNA; D013132:Spinocerebellar Degenerations / Q000150:complications* / Q000175:diagnosis / Q000235:genetics; D018911:Trinucleotide Repeats / Q000235:genetics
chemical_list: D015220:Calcium Channels; D004247:DNA