Autism and Down Syndrome

What Does It Mean?

Behavioral Findings

Obtaining a diagnosis of DS-ASD is rarely helpful in understanding how ASD affects your child. And even when parents obtain a diagnosis, there's a dearth of available information, making it difficult to discern appropriate medical and educational options. To determine what behaviors are most common in DS-ASD, we are conducting case-control studies that randomly match (for gender and age) a child with DS-ASD with a child who has Down syndrome without ASD. These comparisons are based on the information obtained from the ABC together with a detailed developmental history and behavioral observation. Through this process we have been able to determine the following:

Children with DS-ASD were more likely to have:

-- History of developmental regression including loss of language and social skills
-- Poor communication skills (many children had no meaningful speech or signing)
-- Self-injurious and disruptive behaviors (such as skin picking, biting, and head hitting or banging),
-- Repetitive motor behaviors (such as grinding teeth, hand flapping, and rocking)
-- Unusual vocalizations (such as grunting, humming, and throaty noises)
-- Unusual sensory responsiveness (such as spinning, staring at lights, or sensitivity to certain sounds),
-- Feeding problems (such as food refusal or strong preference for specific textures)
-- Increased anxiety, irritability, difficulty with transitions, hyperactivity, attention problems, and significant sleep disturbances

Other observations include:

-- Children with DS-ASD scored significantly higher than their peers with Down syndrome alone on all five subscales of the ABC: sensory function, social relating, body and object use, language use, and social skills.
-- Children with DS-ASD show less impairment in social relatedness than those with ASD only.
-- Children with DS-ASD show more preoccupation with body movement and object use than children with ASD alone.
-- Children with DS-ASD scored higher on all five subscales of the ABC than children with severe cognitive impairment alone.
-- Among children with Down syndrome only, even those with severe cognitive impairment do not always meet the criteria for ASD.

The conclusion I draw from this data is that children with DS-ASD are clearly distinguishable from both "typical" children with Down syndrome and those with severe cognitive impairment (including children with Down syndrome). Thus, it is probably incorrect to suggest autistic-like behaviors are entirely due to lower cognitive function. However, the fact that autistic features and lower cognition are associated indicates there is some shared determinant (or multiple determinants)) common to both features (ASD and lower cognition) of the condition.

Associated Medical Conditions

There are questions about the possibility of similarities in the variety of medical conditions associated with Down syndrome in general in children with DS-ASD. To determine this, we used the same matching scheme as described above. It is important to point out that the number of matched pairs currently in our study is quite small, and, as a result, some of these findings may not hold up as we examine more children.
DS/ASD children were more likely to have:

-- Congenital heart disease and anatomical GI tract anomalies
-- Neurological findings, (i.e., seizures, dysfunctional swallowing, severe hypotonia and motor delay)
-- Opthamologic problems
-- Respiratory problems (i.e., pneumonia and sleep apnea)
-- Increased total number of medical conditions

What Now?

After the Evaluation

If your child has DS-ASD, obtaining the diagnosis or label may be a relief of sorts. The addition of ASD brings new questions. From a medical perspective, it is important to consider use of medication, particularly in older children, for specific behaviors. This is especially true if these behaviors interfere with learning or socialization. Although there is no cure or remarkably effective treatment for Down syndrome and autistic spectrum, certain "target behaviors" may be responsive to medication. Some of these behaviors include:

-- Hyperactivity and poor attention
-- Irritability and anxiety
-- Sleep disturbance
-- Explosive behaviors resulting in aggression or disruption (can sometimes be reduced)
-- Rituals and repetitive behaviors (can sometimes be reduced)
-- Self-injury (can sometimes be reduced)

As you continue to take care of your child, make a point to take care of yourself and your family -- in that order. You have a life and a family to consider. Recognize that there is only so much time, energy, and resources that you can put into this "project." Of course there will be cycles of good times and bad, but if you can't find some way to renew your spirit, then burn-out is inevitable. There is a higher rate of anxiety, sleep problems, lack of energy, depression, and failed or struggling marriages under these circumstances. Learn to recognize your own difficulties, and be honest with yourself and your spouse about the need for help. Counseling and medication may go a long way in helping you to be at your best, for everyone's sake.


Clearly there is a great deal to be learned about children with Down syndrome who are dually diagnosed with autism spectrum disorder. In the meantime, it is essential for parents to educate themselves and others about this condition. Families must work on building a team of health-care professionals, therapists, and educators who are interested in working with their child to promote the best possible outcome. Research efforts must move beyond mere description to address causation, early identification, and natural history. Specific markers in the development of the brain that can distinguish DS-ASD from "typical" Down syndrome and "typical" autism need to be sought, and the possible benefits of various treatments need to be more carefully documented. It will take a very long time to reach these goals, and we should approach them with a spirit of support, cooperation, and caring -- both for individual children and the larger community of children with DS-ASD.

Originally featured on National Down Syndrome Society ( and reprinted with permission. Copyright ? 2012 Meredith Corporation.

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