Children who suffer from a genetic disorder called 22q11.2 deletion syndrome may be at risk of being misdiagnosed with autism, according to a study published in the Journal of Autism and Developmental Disorders.
The researchers, from the MIND Institute at the University of California, Davis, say that as children with 22q11.2 deletion syndrome (22q) are frequently believed to have autism, they could be misdiagnosed because the social impairments linked to their developmental delay could “mimic” the features of autism.
The 22q deletion disorder is caused by a missing section of chromosome 22. According to the International 22q11.2 Foundation, the disorder is present in 1 out of every 2,000-4,000 live births and is almost as common as Down syndrome.
Key elements of the disorder include heart defects, palate differences, immune system deficits, kidney problems and growth delay.
Additionally, symptoms include cognitive, developmental and speech delays, and behavioral, emotional and psychiatric problems – symptoms similar to those of autism.
The researchers note that in the past, parents of children with 22q have often commented that their children “seemed different,” compared with children who had been diagnosed with autism, but they had yet to be presented with a better diagnosis.
Therefore, the research team set out to determine whether children with the disorder meet the specific criteria used to diagnose classic autism.
For the study, the researchers recruited 29 children from the website of the Cognitive Analysis and Brain Imaging Laboratory (CABIL). Of these, 16 were boys and 13 were girls.
The children were required to carry out two tests. The first was the Autism Diagnostic Observation Schedule (ADOS) – a gold-standard assessment for autism.
The second test required the children’s parents to complete the Social Communication Questionnaire (SCQ). This is a 40-question parent-screening tool for communication and social functioning, based on the gold-standard Autism Diagnostic Interview-Revised.
The researchers point out that typically, elevated scores on both a directly administered assessment, such as ADOS, and a parent report measure, such as SCQ, lead to the diagnosis of autism spectrum disorder.
They also note that previous studies of autism in children with 22q deletion syndrome have only used parent report measures.
The results showed that none of the children had elevated scores in both the ADOS and SCQ tests, which would lead to a diagnosis of autism spectrum disorder.
From the ADOS diagnostic tool, only 5 of the 29 children reported elevated scores, and 4 out of these 5 showed significant symptoms of anxiety. Only 2 of the 29 children had elevated scores in the SCQ test.
Kathleen Angkustsiri, assistant professor of developmental-behavioral pediatrics at the MIND Institute and lead study author, says:
“The results of our study show that of the children involved in our study, no child actually met strict diagnostic criteria for an autism spectrum disorder.”
“This is very important because the literature cites rates of anywhere from 20-50% of children with the disorder also have an autism spectrum disorder. Our findings lead us to question whether this is the correct label for these children who clearly have social impairments. We need to find out what interventions are most appropriate for their difficulties.”
Tony Simon, professor of psychiatry and behavioral sciences, and director of the chromosome 22q11.2 deletion program at the MIND Institute, notes that although it is clear that children with the 22q disorder do have social impairments, this has more to do with developmental delay and intellectual disability than classic autism.
“[Children with 22q11.2] often have very high levels of social motivation. They get a lot of pleasure from social interaction, and they’re quite socially skilled,” he adds.
“If you put them with their younger siblings’ friends, they function very well in a social setting, and they interact well with an adult who accommodates their expectations for social interaction.”
The researchers conclude that further studies are needed to assess more appropriate treatments for children with 22q11.2, such as improving communication skills, treating their anxiety and helping them to remain focused on tasks.
“There are a variety of different avenues that might be pursued rather than treatments that are designed to treat children with autism,” adds Prof. Angkustsiri.
“There are readily available, evidence-based treatments that may be more appropriate to help maximize these children’s potential.”