Autism in Down's syndrome: a family history study.
Autism traits cluster in families even when autism rides along with Down syndrome, so ask about the whole family picture.
01Research in Context
What this study did
Ghaziuddin (2000) asked a simple question. If a child has both Down syndrome and autism, do autism traits run in the family?
They talked to families of kids with Down syndrome only and kids with Down syndrome plus autism. Then they counted how many parents and siblings showed mild autism traits.
What they found
Families of Down syndrome plus autism kids had more relatives with subtle autism features. The features were social quirks, rigid routines, or unusual speech.
This pattern mirrors what we see in families of kids with autism alone. It hints that shared genes may sit behind both diagnoses.
How this fits with other research
Machado et al. (2024) widens the lens. They found that parents of kids with autism or sensory processing disorder both show sensory issues and trouble naming feelings. Their data say the "broader autism phenotype" is not autism-specific.
Ghaziuddin (2000) focused only on autism traits. Machado et al. (2024) says we should also ask about sensory and emotional processing when we screen parents.
Huang et al. (2014) and Walley et al. (2005) remind us that Down syndrome itself brings other risks like early dementia. Autism is only one piece of the puzzle.
Why it matters
When you assess a child with Down syndrome and autism, take a quick family history. Ask about social oddities, strict routines, or sensory quirks in parents and siblings. If these traits pop up, plan for more intense social and communication teaching. Also share this news with medical providers so they watch for co-occurring conditions across the lifespan.
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02At a glance
03Original abstract
Several recent reports have described the occurrence of autism in subjects with Down's syndrome (DS). However, relatively little is known about the family history of these subjects, especially with reference to autism. In order to address this issue, the present author examined 11 subjects with DS and autism (DSM-III-R; nine males), and compared them with seven controls with DS but without autism (DSM-III-R; three males). Details about family psychiatric history were obtained from both groups with an emphasis on autism and related disorders. Subjects with both DS and autism had an excess of first-degree relatives who met the description of the broader phenotype of autism. Seven (64%) of the subjects with autism had an affected parent as against one (14%) of the control group. Similarly, four out of 11 siblings (36%) in the DS with autism group showed features suggestive of the broader autistic phenotype compared to none in the control group. These findings suggest that, at least in some cases, autism-specific genetic factors may be important even when autism occurs in the presence of known medical conditions. Further studies of the mechanism of comorbidity of autism with medical conditions may help clarify the aetiology of the disorder.
Journal of intellectual disability research : JIDR, 2000 · doi:10.1046/j.1365-2788.2000.00271.x