Prevalence of Returnable Genetic Results Based on Recognizable Phenotypes among Children with Autism Spectrum Disorder

The importance of extensive genetic testing of autism spectrum disorder (ASD) cases has been demonstrated repeatedly in research settings but such testing in clinical settings remains sporadic. Determining which individuals should be prioritized for expensive tests remains a challenge. Several guidelines have been released relating to clinical genetic evaluations and testing in the context of ASD and these guidelines may be informed by the results of genetic testing in large research cohorts. The current study summarizes findings from over 2,000 individuals with ASD who received genetic testing, including microarray and exome testing, through the Simons Simplex Consortium. A returnable genetic result is identified in 10% of cases, however, this yield increases based on four readily accessible phenotypes: female sex and the presence of intellectual disability, seizures or delayed walking. Combinations of these factors increase return rate further, with some combinations yielding a return rate over 50%. In conclusion, these four phenotypes provide a simple approach to prioritize genetic testing in a clinical setting and inform future clinical guidelines. Providing a systematic approach to decisions about who to test removes barriers for, and therefore decrease disparities in, reimbursable genetic testing for individuals diagnosed with ASD.