Screening for Autism Spectrum Disorder in High-Risk Younger Siblings.

Most autism spectrum disorder (ASD) screening measures have been developed for use with low-risk (LR) children; however, measures may perform differently in high-risk (HR) younger sibling populations. The current study sought to investigate the performance of an ASD screening measure, the Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F), in a sample of HR younger siblings and directly compared its performance with that in an LR sample.