J Med Genet 45:290-297 doi:10.1136/jmg.2007.054676
  • Original article

Detection of early FXTAS motor symptoms using the CATSYS computerised neuromotor test battery

  1. E G Allen,
  2. J Juncos,
  3. R Letz,
  4. M Rusin,
  5. D Hamilton,
  6. G Novak,
  7. L Shubeck,
  8. S W Tinker,
  9. S L Sherman
  1. Emory University, Atlanta, Georgia, United States
  1. Dr E Graves Allen, Emory University, Department of Human Genetics, 615 Michael Street, Suite 301, Whitehead Research Building, Atlanta, Georgia 30322, USA; egraves{at}
  • Received 21 September 2007
  • Revised 7 December 2007
  • Accepted 10 December 2007
  • Published Online First 30 January 2008


Background: Carriers of the FMR1 premutation allele are at a significantly increased risk for a late-onset neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome (FXTAS). This disorder is distinct from fragile X syndrome (FXS) in its molecular aetiology and clinical presentation. The primary features of FXTAS are late-onset intention tremor and gait ataxia. Associated features include parkinsonism, neuropsychological dysfunction, autonomic dysfunction and peripheral neuropathy.

Aim: To investigate the usefulness of a quantitative neurological test battery implemented through the CATSYS instrument to identify preclinical symptoms of FXTAS.

Methods: Both premutation carriers with 70–199 repeats (62 men) and their low-repeat allele carrier siblings (27 men), identified through families with an individual affected with FXS, were tested.

Results: As expected, because of its sensitivity, use of the instrument allowed identification of tremor in 23% of men who had not self-reported tremor, and ataxia in 30% of men who had not self-reported ataxia. Among subjects with self-reported tremor and ataxia, we found significant concordance between measures of the CATSYS system and the self-report.

Conclusion: Rates of these traits among premutation carriers and low-repeat allele carrier siblings could be identified, and are presented in this paper, along with the minimum estimates of age-related prevalence.


  • Competing interests: None declared.