Genetic Testing History in Adults with Autism Spectrum Disorder

Many genes have been identified in autism spectrum disorder (ASD). Yet little is known about how many adults with ASD receive recommended genetic testing and their outcomes. We investigated the percentage of adults with ASD who received genetic testing using recommended methods in our ASD specialty clinic and the percentage with positive findings.

Potentially eligible adults were identified through search of our health system data repository and ASD diagnoses confirmed using review of relevant medical records by consensus of psychiatrists specializing in ASD. Patients were included (N=630) who had at least one visit with a qualifying clinician between 5/1/2010 and 12/15/2020 and demographic data available. Data were collected through manual retrospective review of the electronic health record.

Only 41% of the adults with ASD (261/630) had a history of genetic testing documented in the medical record. Genetic testing was declined by patients or families for 11% (72) of records and not recorded in 47% (297). Mean (SD; range) age for the 261 adults with testing documented was 28.5 (5.3; 22-58) years. Sixty-seven (26%) were identified as female, 14 (6%) as Asian, 8 (3%) as Black or African American, 226 (89%) as White, 6 (2%) as other race, and 2 (1%) as Hispanic. 189 (73%) had intellectual disability. Ninety-one percent (236) had the genetic testing method recorded. Only 54% (95% CI: 46%, 61%) of patients had testing using a recommended method (chromosomal array, autism/intellectual disability sequencing panel, or exome sequencing). Few adults had received testing with sequencing technologies. A genetic cause of ASD was found in 28% (95% CI: 19%, 39%) of the 121 adults with results from ASD-related genetic testing recorded.

Genetic testing can offer clinical and research insights. Yet it is underutilized in this population of adults with ASD. Nearly half of the adults in our sample lacked documentation of genetic testing. Thus, the percentage of adults with confirmed ASD who had any recommended genetic testing may be even lower than reported. Adults with ASD may benefit from having their genetic testing history reviewed in the clinic and the latest genetic testing performed.