Journal of Autism and Developmental Disorders

, Volume 32, Issue 2, pp 107–114

Longitudinal Changes in Cognitive and Adaptive Behavior Scores in Children and Adolescents with the Fragile X Mutation or Autism


  • Gene S. Fisch
    • School of MedicineYale University
  • Richard J. Simensen
    • Greenwood Genetics Center
  • R. J. Schroer
    • Greenwood Genetics Center

DOI: 10.1023/A:1014888505185

Cite this article as:
Fisch, G.S., Simensen, R.J. & Schroer, R.J. J Autism Dev Disord (2002) 32: 107. doi:10.1023/A:1014888505185


Studies of the relationship between the fragile X (FRAXA) mutation and autism have been controversial. Although there are differences between the two populations, individuals with FRAXA and autism exhibit remarkably similar aberrant behavior patterns. We examined comparably aged children and adolescents with FRAXA or autism to determine whether longitudinal changes in cognitive ability and adaptive behavior were similar in the two groups. We found decreases in IQ scores in young children with FRAXA as well as in those with autism. Declines in IQ scores were steeper among children with FRAXA. Older children and adolescents with autism exhibit stable test-retest scores, whereas older children with FRAXA continue to show decreases. Comparable declines in adaptive behavior composite scores were observed in both groups, at all ages tested, and across all adaptive behavior domains.

Autismfragile Xcognitive abilityadaptive behaviorlongitudinal studies

Copyright information

© Plenum Publishing Corporation 2002