Prepulse inhibition in fragile X syndrome: feasibility, reliability, and implications for treatment

Am J Med Genet B Neuropsychiatr Genet. 2009 Jun 5;150B(4):545-53. doi: 10.1002/ajmg.b.30858.


Pharmacological rescue of behavioral, cognitive and synaptic abnormalities in the animal models of fragile X syndrome (FXS) has prompted the initiation of clinical trials of targeted treatments in humans with this condition. Objective, well-validated outcome measures that are reflective of FXS deficits and can be modeled similarly in animal and human studies are urgently needed. A protocol measuring prepulse inhibition (PPI) of the startle reflex, including measures of test-retest stability, was evaluated in 61 individuals with the fragile X full mutation (40 males and 21 females; 19.18 +/- 7.18 years) and 63 age-matched normal controls (35 males and 28 females; 20.83 +/- 6.96 years) across two laboratory sites with identical equipment and protocols. Relative to controls, the fragile X group had PPI impairment of 26%, 22%, and 28% for 60, 120, and 240 ms prepulse interval trial types, respectively, P = 0.000002. PPI test-retest reliability in 29 of the participants was excellent for the 120 ms prepulse interval trials (intraclass correlations: FXS, 0.85; controls, 0.88, 0.89 overall). This study demonstrates the feasibility and reliability of PPI measurement in a developmentally disabled population and highlights its potential as an outcome measure to test the efficacy of targeted neurotherapeutic agents.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Adolescent
  • Adult
  • Attention Deficit Disorder with Hyperactivity / etiology
  • Attention Deficit Disorder with Hyperactivity / physiopathology
  • Case-Control Studies
  • Clinical Trials as Topic
  • Cognition Disorders / etiology
  • Cognition Disorders / physiopathology
  • Female
  • Fragile X Syndrome / genetics
  • Fragile X Syndrome / physiopathology*
  • Fragile X Syndrome / therapy
  • Humans
  • Male
  • Neuropsychological Tests
  • Reaction Time / physiology
  • Reflex, Startle*
  • Reproducibility of Results
  • Sensory Gating*
  • Young Adult