Autism spectrum disorder (ASD) symptom profiles of children with comorbid Down syndrome (DS) and ASD: A comparison with children with DS-only and ASD-only.
Kids with DS+ASD show equal social-communication and repetitive-behavior symptom severity—unlike ASD-only—so tailor assessments and treatments accordingly.
01Research in Context
What this study did
Godfrey et al. (2019) compared autism traits in three groups: kids with Down syndrome plus ASD, kids with Down syndrome only, and kids with ASD only. Parents filled out standard autism questionnaires. The team looked at social-communication scores and repetitive-behavior scores for each child.
What they found
Children with DS+ASD showed a different pattern than the other two groups. Their social-communication problems were just as severe as their repetitive behaviors. In plain words, the two main autism areas were equally strong. This differs from typical ASD-only profiles, where social issues usually outrank repetitive behaviors.
How this fits with other research
Amaral et al. (2017) ran a near-identical comparison and saw the same equal balance of symptoms, so the finding is holding up across studies. Schwichtenberg et al. (2013) reported that only 19 % of kids with Down syndrome meet ASD cut-off, while Ding et al. (2017) found 37 %. Mary et al. do not give a percent, but all three papers agree the group exists and needs special attention.
Lunsky et al. (2011) used cluster math to show DSM criteria work in Down syndrome and hinted at two ASD subtypes. Mary et al. add detail by showing one clear subtype: kids whose social and repetitive scores line up evenly. Together the studies say, "Yes, diagnose ASD in DS, but watch for this balanced profile."
Why it matters
If you assess a child with Down syndrome, do not assume weak social skills are "just the DS." Use autism screeners and look for the equal-severity pattern. When both social and repetitive scores are high, plan interventions that target both areas together. Tailor goals to the child’s verbal level, because Mary et al. link verbal scores to social-communication gaps. Share the profile with parents so they understand why therapy looks different from a typical ASD program.
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02At a glance
03Original abstract
BACKGROUND: Down syndrome (DS) is associated with increased rates of autism spectrum disorder (ASD), characterized by social-communicative impairments (SOC-COM) and repetitive behaviors and interests (RBI). However, little is known about the ASD symptom presentation in children with DS + ASD. AIMS: The current study sought to describe parent-report of SOC-COM and RBI symptoms on the Autism Diagnostic Interview -Revised (ADI-R) in children with DS (n = 22), DS + ASD (n = 11), and ASD (n = 66). METHOD: SOC-COM and RBI scores from the ADI-R were compared across the groups whose autism status was ascertained using the Autism Diagnostic Observation Schedule. RESULTS: Differences in SOC-COM and RBI symptom severity was observed. The general pattern of findings was ASD > DS+ASD > DS. Dissimilar ASD symptom profiles were observed across groups. In ASD, SOC-COM scores were higher than RBI scores; in DS + ASD, similar SOC-COM and RBI scores were observed. Lastly, SOC-COM impairments were highly related to verbal cognition in youth with DS + ASD but not in those with DS or ASD. CONCLUSIONS AND IMPLICATIONS: These findings suggest that children with DS + ASD have a distinct profile of ASD symptoms that differs from peers with either disorder in isolation. Thus, care should be taken in evaluating and designing treatments for this group.
Research in developmental disabilities, 2019 · doi:10.1016/j.ridd.2019.03.003