Introduction
There is relatively little research and commentary addressing the dual diagnosis of Down syndrome and autism spectrum disorder (DS-ASD). Until fairly recently it was believed that the two conditions could not co-exist. Parents were often told that their child with Down syndrome had severe or profound intellectual disability, without further investigation or intervention to identify a diagnostic cause.
Today, clinicians recognise that people with Down syndrome may also have a co-occurring psychiatric diagnosis, such as autism spectrum disorder or obsessive-compulsive disorder (OCD). Because this is a relatively new understanding within both the medical and educational communities, there is still a lack of knowledge about the needs of children and adults with DS-ASD.
Group One: Early Indicators
Children in this group appear to display "atypical" behaviours from an early age. During infancy and early childhood, the following may be observed:
- Repetitive motor behaviours (fingers in mouth, hand-flapping).
- Fascination with lights, or fixation on ceiling fans or fingers.
- Marked food refusal.
- Difficulties with receptive language (impaired comprehension and use of gesture) that can make the child appear deaf; spoken language may be highly echolalic or absent altogether.
- Associated medical conditions including seizures, swallowing difficulties, nystagmus (involuntary eye movement), or severe hypotonia with delayed motor skills.
If the child with Down syndrome is very young, only one or a few of the above behaviours may be apparent — this does not necessarily mean the child will develop autism spectrum disorder. It does, however, warrant close monitoring, and the child may benefit from intervention services (such as sensory integration therapy) and educational strategies (such as visual communication approaches or discrete trial teaching).
Group Two: Developmental Regression
Children in this group are typically older and experience a significant regression (or decline) in the acquisition and use of language and social communication skills. This developmental regression may be accompanied by increased irritability, anxiety, and the emergence of repetitive behaviours.
Parents frequently report that this regression occurred after a period of "typical" early development. According to families, this regression most commonly occurs between the ages of three and seven years.
Closing Remarks
The medical concerns and strategies may differ between these two groups. Regardless of how and when autism spectrum disorder is first identified, however, children with both Down syndrome and ASD share similar educational and behavioural needs at the time of diagnosis.
Source: Reproduced under an exclusive agreement with the National Down Syndrome Society (NDSS) — www.ndss.org