title: Spinocerebellar ataxia type 3 presenting as an L-DOPA responsive dystonia phenotype in a Chinese family.
abstract: The clinical spectrum of spinocerebellar ataxia 3 (SCA 3) disease is wide and varied. We describe a Chinese patient with a mutation at the SCA 3 locus with clinical features of levodopa-responsive dystonia. The family history was suggestive of being autosomally dominant. Levodopa responsiveness though rare has been described in families with features of parkinsonism. Noteworthy is the relatively late onset of disease (>40 years) possibly explained by the low number of affected alleles at 59, the usual range being from 62 to 86, with the lowest recorded number at 56. This expands the wide and varied phenotypic manifestations of SCA 3, and highlights the observation that features suggestive of levodopa-responsive dystonia (DRD) such as focal dystonia, gait difficulty with diurnal fluctuation of symptoms, and a marked response to low doses of levodopa can be presenting features of SCA 3. SCA 3 should be considered a differential diagnosis in adult patients who present with DRD phenotype and with a positive family history.
authors.affiliation: Division of Neurology, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074, Republic of Singapore. mdcwse@nus.edu.sg
authors.forename: E
authors.initials: E
authors.lastname: Wilder-Smith
authors.forename: E K
authors.initials: EK
authors.lastname: Tan
authors.forename: H Y
authors.initials: HY
authors.lastname: Law
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: I
authors.initials: I
authors.lastname: Ng
authors.forename: M C
authors.initials: MC
authors.lastname: Wong
mesh_terms: D000328:Adult; D044466:Asian People; D015139:Blotting, Southern / Q000379:methods; D004252:DNA Mutational Analysis / Q000379:methods; D004421:Dystonia / Q000188:drug therapy* / Q000209:etiology; D005192:Family Health; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D017827:Machado-Joseph Disease / Q000188:drug therapy* / Q000235:genetics; D008279:Magnetic Resonance Imaging; D009154:Mutation; D010641:Phenotype
chemical_list: D007980:Levodopa