title: Myoclonus in ataxia-telangiectasia.
abstract: BACKGROUND
  Various movement disorders can be found in ataxia-telangiectasia (AT), including ataxia, dystonia, chorea, and myoclonus, but myoclonus has rarely been described as the predominant feature in AT.
  
  
  METHODS
  We report two AT patients with prominent myoclonus, illustrating an unusual presentation of this disorder. Sequencing of the ATM gene in the first patient revealed a homozygous truncating mutation, c.5908C>T (p.Q1970*) in exon 38 of the ATM gene, which has been previously reported as a founder mutation in the Costa Rican population.
  
  
  CONCLUSIONS
  Myoclonus can be a predominant or presenting feature in AT, even without dystonia.
authors: Movement Disorder Division, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors: Pichet
authors: P
authors: Termsarasab
authors: Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors: Amy C
authors: AC
authors: Yang
authors: Movement Disorder Division, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors: Steven J
authors: SJ
authors: Frucht
keywords: Ataxia; founder mutation; myoclonus; telangiectasia