Despite Recommendations, Autism Patients Are Not Fragile X, Karyotype or CMA Testing

Whether due to lack of insurance coverage, personal preference or other reasons, patients with autism spectrum disorder (ASD) are not getting recommended genetic testing. That is the conclusion of a new study published in Jama Psychology documenting a disturbing disconnect between professional recommendations and clinical practice. The Diagnostic Challenge ASD is among the most strongly genetic neuropsychiatric conditions, with an increased frequency of rare, deleterious copy number variants and single-nucleotide variants. Several medical professional societies recommend Chromosomal Microarray Analysis (CMA) and fragile X testing for people with ASD, and there is growing support for exome sequencing upfront. In addition, as noted in the autism section of the U.S Centers for disease Control’s (CDC) website, clinical practice recommendations from the Academy of Neurology and the Child Neurology Society call for genetic testing in children with autism. The Study The study, which was approved by the institutional review board at Lifespan and conducted by Dr. Eric Morrow, PhD, head of the Developmental Disorders Genetics Research Program at Brown University and colleagues, evaluated self-reported data on testing in 1,280 people with ASD. Diagnosis of ASD had been confirmed, based on assessment with the Autism Diagnostic Observation Schedule. Participants were between the ages of 1.75 and 68 years, with the following breakdown:

• 0-4 years: 172 participants;
• 5-9 years: 360;
• 10-14 years: 408;
• 15-19 years: 208; and
• 20+ years:132.

Among participants with confirmed ASD diagnosis, only 16.5 percent reported having received some genetic testing. The breakdown:

• Fragile X:13.2 percent (169 participants);
• Karyotype: 7.2 percent (92); and
• CMA: 4.5 percent (57).

Only three percent of participants reported having received both Fragile X and CMA testing. Another 9.4 percent reported that they were unsure whether they had received any testing, and 21.4 percent did not answer the survey. Takeaway The study authors suggested multiple reasons for the discrepancy between recommendations and actual testing including:  

• Participant preferences;
• Insurance coverage constraints—there was no difference in CMA testing in participants with and without private insurance but there was a strong increase in testing in participants with public insurance;
• Limits in clinician knowledge and comfort with genetic testing, with the data showing a lower frequency of genetic testing in people diagnosed with ASD by psychiatrists and psychologists; and
• Changes in genetic testing practices over time and a reduced likelihood of adults with ASD being offered testing.