Improving the Diagnosis of Autism Spectrum Disorder in Fragile X Syndrome by Adapting the Social Communication Questionnaire and the Social Responsiveness Scale-2

J Autism Dev Disord. 2020 Sep;50(9):3276-3295. doi: 10.1007/s10803-019-04148-0.


We carried out a psychometric assessment of the Social Communication Questionnaire (SCQ) and the Social Responsiveness Scale (SRS-2) in fragile X syndrome (FXS), relative to clinician DSM5-based diagnosis of autism spectrum disorder (ASD) in FXS. This was followed by instrument revisions that included: removal of non-discriminating and/or low face validity items for FXS; use of receiver operating characteristic (ROC) curves to determine optimal cut points for the original and revised measures; an exploratory factor analysis to outline subscales better representing ASD in FXS; and creation of a "triple criteria" diagnosis to better delineate ASD subgroups in FXS. These methods improved the sensitivity and/or specificity of the SCQ and SRS-2, but diagnostic accuracy of ASD remains problematic in FXS.

Keywords: Autism spectrum disorder; Exploratory factor analysis; Fragile X syndrome; Receiver operating characteristic curves; Social Communication Questionnaire; Social Responsiveness Scale-2.

MeSH terms

  • Adolescent
  • Adult
  • Autism Spectrum Disorder / diagnosis*
  • Autism Spectrum Disorder / psychology
  • Child
  • Child, Preschool
  • Communication*
  • Cross-Sectional Studies
  • Female
  • Fragile X Syndrome / diagnosis*
  • Fragile X Syndrome / psychology
  • Humans
  • Interpersonal Relations*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Psychometrics / standards
  • Registries
  • Social Communication Disorder / diagnosis
  • Social Communication Disorder / psychology
  • Surveys and Questionnaires* / standards
  • Young Adult