Genetic Testing for People with Intellectual and Developmental Disabilities

Matthew Rucker; Braden Friedman; Takahiro Soda, MD

Overview

Genetic testing is becoming an important part of the standard of care for people with IDD. It offers significant benefits not only to patients, but also to caregivers and families. Integrating genetic information into clinical practice promotes patient self-advocacy and enhances healthcare equity for individuals with developmental disabilities. Table 1 shows the genetic testing guidelines from key organizations. 

Table 1: Guideline Summary from Key Organizations1

OrganizationRecommendation
American Academy of Child and Adolescent Psychiatry (2020)Chromosomal microarray (CMA) and Fragile X (FMR1) testing; consider exome sequencing (ES) if etiology remains unclear
American Academy of Pediatrics (2014, 2020)CMA and FMR1 repeat analysis; refer for ES if necessary
American College of Medical GeneticsRecommend ES or genome sequencing (GS) as a first- or second-tier test for individuals with ASD or developmental delay

Benefits of Genetic Testing

  • Medical Explanation:2 Genetic testing provides a clear, actionable medical explanation, replacing vague or non-specific causes.
  • Decreased Stigma:2 Identifying genetic causes of IDD or ASD can help reduce stigma by reframing the diagnosis as biological rather than purely psychiatric.
  • Targeted Management:1 A confirmed genetic diagnosis guides clinicians and caregivers in anticipating comorbid conditions and planning appropriate care.
  • Ends the Diagnostic Odyssey:1 A conclusive genetic diagnosis can bring clarity after years of inconclusive or fragmented evaluations.
  • Informs Reproductive Decision-Making:1 Know whether variants are inherited or de novo can help families assess future pregnancy risks.

Considerations for Testing

Prescribers should know that insurance coverage for genetic testing varies between Medicaid, Medicare, and commercial insurance plans.3,4 Insurance coverage also varies across states, particularly for Medicaid.4 Prior to ordering the genetic testing, it is important to confirm if the recommended genetic test is covered by the patient’s insurance plan and provide appropriate documentation for the testing, such as the developmental history, physical exam findings, and recommended tests.  

Prescribers should obtain informed consent, discuss the potential benefits, limitations, and ethical implications of genetic testing.5 Patients and families should be informed regarding the need for prior authorization or out-of-pocket costs. Involving a genetic counselor or geneticist, if accessible, can help guide the process, test selection, and interpretation.5 

References

  1. Ledbetter DH, Finucane B, Moreno-De-Luca D, Myers SM. (2025). Mainstreaming diagnostic genetic testing and precision medicine for autism spectrum disorder. Psychiatric Clinics of North America.
  2. Finucane BM, Myers SM, Martin CL,  Ledbetter DH. (2020). Long overdue: Including adults with brain disorders in precision health initiatives. Current Opinion in Genetics & Development, 65, 47–52.
  3. Finucane BM, Ledbetter DH, Vorstman JAS. (2021). Diagnostic genetic testing for neurodevelopmental psychiatric disorders: Closing the gap between recommendation and clinical implementation. Current Opinion in Genetics and Development, 68, 8–
  4. Genetics Policy Hub. (n.d.). Medicaid Coverage. Retrieved July 20, 2025, from https://geneticspolicy.nccrcg.org/medicaid-coverage/
  5. Hunt Brendish K, Patel D, Yu K, Alexander CK, Lemons J, Gunter A, Carmany EP (2021). Genetic counseling clinical documentation: Practice Resource of the National Society of Genetic Counselors. Journal of Genetic Counseling, 30, 1336–1353. https://doi.org/10.1002/jgc4.1491