Assessment & Research

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

Kidd et al. (2020) · Journal of autism and developmental disorders 2020
★ The Verdict

Trimming items and moving cut-points makes SCQ and SRS-2 more accurate for ASD in fragile X, yet diagnosis still needs clinical backup.

✓ Read this if BCBAs who assess or treat children with fragile X syndrome.
✗ Skip if Clinicians who only serve idiopathic ASD without genetic comorbidities.

01Research in Context

01

What this study did

The team wanted better autism screens for kids with fragile X.

They trimmed weak items from two parent forms: SCQ and SRS-2.

New cut-points were set using a FXS sample with known ASD status.

02

What they found

The shorter forms caught more true cases and cut false alarms.

Sensitivity and specificity both rose, but some kids were still missed.

No score gave a perfect yes-or-no answer.

03

How this fits with other research

Honigfeld et al. (2012) also used SRS-2 in genetic disorders.

They showed extra Y chromosomes raise social scores more than FXS.

The new FXS cut-points would over-flag those boys, so use syndrome-specific norms.

Klein et al. (2024) just updated the autism ICF Core Sets.

Their sensory items echo the social items kept in the FXS revision.

Both papers push the same theme: tailor tools to the client in front of you.

04

Why it matters

If you screen a child with FXS, swap in the revised SCQ and SRS-2 forms.

They reduce false negatives, so fewer kids slip through the cracks.

Still pair the scores with clinical judgment; a single number is not enough.

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→ Action — try this Monday

Download the revised SCQ/SRS-2 FXS forms and re-score last month’s evaluations.

02At a glance

Intervention
not applicable
Design
other
Population
developmental delay
Finding
positive
Magnitude
small

03Original abstract

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.

Journal of autism and developmental disorders, 2020 · doi:10.1007/s10803-019-04148-0