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Tool helps identify those risk for autism spectrum disorder

The Autism Observation Scale for Infants, or AOSI, can help ascertain young children with tuberous sclerosis complex who are at higher risk for autism spectrum disorder, according to findings recently published in Pediatric Neurology.

According to researchers, tuberous sclerosis complex (TSC) occurs in one out of every 6,000 people.

“Currently, no single factor has been identified as a consistent predictor of [autism spectrum disorders (ASD)]; but single-gene disorders with a high prevalence of ASD, such as TSC, provide us with opportunities to investigate the underlying biology and identify potential treatments,” Jamie Capal, MD, of the division of neurology at the Cincinnati Children’s Hospital Medical Center, and colleagues wrote. “Evaluation of the AOSI as an objective assessment tool to identify early ASD-associated behaviors in infants with TSC has been shown in a small prospective longitudinal cohort of infants, but using the AOSI to predict later ASD risk in this population has not been previously reported.”

To see if AOSI could be used a prediction tool, researchers analyzed test results from 79 children between 0 to 36 months of age with TSC who were given the AOSI at 12 months. These participants were also given both the Autism Diagnostic Observation Schedule-2 (ADOS-2) and Autism Diagnostic Interview-Revised at 24 months. The children were categorized as ASD or non-ASD according based on the ADOS-2 results.

Capal and colleagues found that those with ASD had a mean AOSI total score at 12 months that was “significantly higher” than the non-ASD group (11.8 ± 7.4 vs. 6.3 ± 4.7).

Researchers also discovered that by utilizing an AOSI total score cut-off of 13, an “excellent specificity” was observed, but was but was significantly “less sensitive” for identifying children who would meet ASD classification at 24 months. Capal and colleagues also determined that a participant’s AOSI total score was helpful for establishing risk for ASD at 24 months as determined by the ADOS-2, and that the OR of the AOSI prognosticating ASD on the ADOS-2 at 24 months was 1.16 (95% CI, CI 1.06-1.27; P < .001).

“Single-gene syndromes with a high prevalence of neurodevelopmental disorders such as TSC provide us with unique opportunities to investigate the underlying biology and identify potential treatments for ASD by providing highly enriched populations in which ASD symptoms can be identified and measured before the formal diagnosis of ASD is made,” Capal and colleagues wrote. “However, evaluation of existing tools such as the AOSI and continued development of new assessment approaches with improved sensitivity and specificity are essential for this progress to take place, not only for TSC but the broad spectrum of ASD causes, including idiopathic ASD.”

Citing the lack of evidence and the low quality of the evidence that is available, or that which conflicts or is of poor quality such as, the U.S. Preventive Services Task Force has previously stated that there is currently insufficient evidence to support universal autism spectrum disorder screening for children aged 18 to 30 months unless concerns are raised by parents or clinicians.

The debate over the use of available screening tests for autism has continued. Since the USPSTF recommendation, another study found that using the Attention Deficit Hyperactivity Disorder Rating Scale Fourth Edition is inaccurate, while another, different study found the Modified Checklist for Autism in Toddlers Follow-up Interview provided accurate and timely outcomes. – by Janel Miller

Disclosure: Capal reports no relevant financial disclosures. Please see the study for the other authors’ relevant financial disclosures.