Adaptive and Behavioral Profiles in Down Syndrome and Co-Occurring Autism Spectrum Disorder: A Case-Control Study.
In kids with Down syndrome, lots of stereotypy and narrow interests—not rituals—flag co-occurring autism and call for fast adaptive-skill help.
01Research in Context
What this study did
Researchers compared kids who have Down syndrome plus autism to kids who only have Down syndrome.
Both groups had the same IQ scores.
They measured daily living skills, stereotypy, and restricted interests.
What they found
The DS+ASD group scored lower on adaptive skills like dressing and talking.
They showed more hand flapping and repeated phrases.
Surprisingly, both groups had similar anxiety and acting-out behaviors.
How this fits with other research
Imam (2001) first showed autistic kids initiate fewer social acts than kids with DS alone.
Elisa et al. now refine that picture: within DS, added autism shows up as extra stereotypy, not new social bids.
Leaf et al. (2012) saw overlap in repetitive acts between ASD and typical toddlers; Elisa’s IQ-matched DS design sharpens the signal, proving frequency alone is not enough—diagnosis within DS matters.
Reddy et al. (2010) found less mirror play in ASD; Elisa links the same social gap to everyday adaptive scores, giving you a practical probe.
Why it matters
If a child with Down syndrome flaps, lines up toys, and uses odd phrases, treat it as an autism red flag.
Start adaptive-skill teaching early—self-care, communication, and play routines.
Skip the wait-and-see; targeted ABA now can close the daily-living gap before school entry.
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02At a glance
03Original abstract
Down syndrome (DS) is the most frequent genetic cause of intellectual disability (ID). Individuals with DS exhibit an elevated risk of other neurodevelopmental disorders, including autism spectrum disorder (ASD). The primary objective of this study was to explore the clinical characteristics of co-occurring ASD in children and adolescents with DS using a case-control approach. We compared the adaptive and behavioral profiles of a group of participants with both DS and ASD (ASD group) with a group of participants with DS-only matched by age, sex, and IQ (CON group). Participants in the ASD group exhibited significantly lower adaptive skills than the CON group, despite the IQ-matching in the moderate/severe ID range. No group differences emerged on internalizing or externalizing behavioral symptoms, but participants in the ASD group exhibited significantly higher social withdrawal, stereotyped behavior, and restricted interests. These findings indicate that, although children with DS-with or without ASD-who have similar low cognitive functioning often exhibit common behavioral traits, paying close attention to the elevation of stereotyped behaviors or restricted interests can improve the detection of co-occurring ASD in this population, enabling more personalized interventions. Conversely, the presence of ritualistic behaviors or behaviors related to insistence on sameness may not be a strong indicator of underlying ASD in children with DS. Additionally, acknowledging that the presence of ASD contributes to adaptive behavior deficits beyond the impact of moderate-to-severe ID alone highlights the critical need for early interventions to enhance daily living skills in this population.
Autism research : official journal of the International Society for Autism Research, 2025 · doi:10.1002/aur.3294