A preliminary study of screening for risk of autism in children with fragile X syndrome: testing two risk cut-offs for the Checklist for Autism in Toddlers.

Researchers tested two sets of cut-off scores on the Checklist for Autism in Toddlers (CHAT). They wanted to see which set better spots autism in toddlers who have fragile X syndrome.

The kids were already diagnosed with fragile X. The team compared the usual CHAT cut-offs with the Denver-modified ones.

The Denver-modified cut-offs caught 75% of the toddlers later found to have autism. The standard cut-offs caught only 50%.

Both sets kept false alarms low, so the Denver version gave more true positives without extra noise.

Jones et al. (1998) used the CARS tool and saw that 25% of young fraX boys scored above the autism cut-off. Their work set the stage for later CHAT tweaks like this one.

Raza et al. (2019) tested the short Q-CHAT-10 in high-risk siblings. Both studies chase the same goal: find autism early with a quick screen. The FXS study adds a genetic-risk twist.

Scarpa et al. (2013) found the M-CHAT over-calls autism in rural, low-SES toddlers. That warning reminds us to check culture and setting before we trust any cut-off, even the Denver one.

If you screen toddlers who have fragile X, switch to the Denver-modified CHAT cut-offs. You will miss fewer kids who actually have autism and still keep false positives low. The whole process takes the same five minutes, but the results are sharper.