Developmental Functioning of Toddlers At-Risk for Autism With and Without Down Syndrome.

PURPOSE: Due to the difficulties in differentiating between impairments associated with intellectual disability and ASD symptomology, DS often leads to delayed or misdiagnoses of ASD.

METHOD: An ANOVA was run to investigate the effects of ASD risk and DS on overall developmental functioning across three groups: ASD+, DS-, and DS+ (n = 138). A MANOVA was run to investigate the differences of group on five developmental subdomains.

RESULTS

The results revealed significant group differences in the overall developmental functioning and each developmental subdomain. Children in the DS+ group demonstrated significantly lower overall developmental functioning, as well as lower adaptive, cognitive, motor, and communication skills compared to their peers; however, children in the DS- group demonstrated significantly better social skills compared to their peers in the ASD+ group.

DISCUSSION: These findings support the need for early screening and identification of ASD among those with DS.