Bridging the Gap: Access to Genetic Testing in a Community Sample of Individuals with Autism Spectrum Disorder

Background: While genetic testing is recommended by the American College of Medical Genetics for individuals with autism spectrum disorder (ASD), access to testing and physician referrals remain limited. Testing for Fragile X syndrome and high-resolution chromosomal microarray are the first-tier genetic tests for individuals with ASD; however, the extent to which they are pursued varies widely. Recently, a medical-center based autism research center, which carries out comprehensive genetic and clinical evaluations, joined with a nonprofit organization, comprising two public charter schools and a foundation providing recreational, therapeutic, and adult services for several hundred individuals with ASD per year, in order to integrate research into a community setting. The joint institute provides genetic testing, facilitated by the research group, to individuals within the school and foundation community.

Objectives: To characterize and assess the likelihood of receiving recommended genetic testing in a community sample of individuals with ASD.

Methods: Between August and November 2018, 45 families were recruited; 15 were enrolled by November 2018, with the remainder expected to participate by March 2019. The 45 screened participants with ASD (17.78% female) ranged in age from 2 to 32 years and all carried Individualized Education Plan (IEP) classifications of ASD and/or a documented diagnosis from medical records. Results from previous genetic testing were obtained, and testing was ordered for those who had not had recommended testing. Saliva samples are collected at the local center, and DNA extraction and testing is facilitated by the research institute. Phenotyping data is being collected through parent report.

Results: Of the participants screened (n=45), 22% had previous genetic testing confirmed by reports. The average year of ASD diagnosis for those with previous genetic testing (n=10) was 2009, while that of the total population was 2008. Average age at diagnosis for those with past testing was 29 months and 36 months for the total population. In our screened sample, 17.78% of individuals were characterized as nonverbal (by parent report), and 4 of those 8 individuals received genetic testing. Of 10 individuals with past testing, 20.0% percent had an autism-related finding (Fragile X syndrome (n=1); STXBP1-associated epileptic encephalopathy (n=1)). Fragile X testing, chromosomal microarray and research whole-exome sequencing results are pending for those whose testing is being conducted through this study.

Conclusions: Preliminary results suggest that genetic testing and referrals in the community remain limited, and that neither year of diagnosis nor age at diagnosis significantly increases the likelihood of genetic testing. An important next step will be to examine additional phenotypes influencing referrals for genetic testing, including IQ, adaptive behavior, and medical and psychiatric comorbidity, as well as source of diagnosis. Future directions include identifying additional barriers to genetic testing and increasing access and ease in community settings where the majority of individuals with ASD are served.