SLPOtherJournal of autism and developmental disorders2025

Assessing Autism Co-Occurrence in Fragile X Syndrome: Proposing a Preliminary CARS-2 Cut-Off Score.

Tiffany Chavers Edgar, Marianne Elmquist, Claudia Schabes and 3 others

PMID 40397047

WHAT IT FOUND

Standard autism rating scales classify far fewer people with Fragile X as autistic than observational assessments do.

A lower cut-off score on the rating scale improved agreement with the observational tool, but these findings are preliminary and require validation in larger, more diverse samples before changing clinical practice.

Key findings

01Using traditional cut-off scores, the observational assessment classified significantly more participants as autistic than the rating scale did.

02A lower cut-off score on the rating scale increased agreement with the observational assessment from fair to substantial.

03The study was limited by a small sample size and the lack of independent administration of the two assessments.

STILL TO COME

How it was doneWhat they foundWhat it means for SLPs

Read the rest of this summary

You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.

Already have one?

What it does not show

The sample size was small, particularly for females and individuals without co-occurring autism, which limits the precision of the results. The same examiners administered both the ADOS-2 and CARS-2, which may have inflated agreement between the tools due to shared impressions. The study did not use a full DSM-5 clinical diagnosis as the gold standard, relying instead on the ADOS-2, which is not a standalone diagnostic tool. The sample lacked racial and ethnic diversity, and all participants had spoken language, so results may not apply to minimally verbal individuals or other demographic groups.

Declared interests

The authors declare no conflicts of interest. The study was supported by grants from the National Institute of Child Health and Human Development and the National Institute on Deafness and Other Communication Disorders.

The easy way to misread this

Do not change your clinical cut-off scores for the CARS-2 in Fragile X syndrome based on this study. The proposed cut-off of 24 is preliminary, derived from a small sample where the same examiners administered both tools, and has not been validated against full clinical diagnoses.

Read it on PubMed →