AAP New Guidelines: Exome and Genome Sequencing Recommended as First-Tier Test for Developmental Delays and Intellectual Disabilities
August 26, 2025
As a pediatrician and clinical geneticist, I’ve seen firsthand how overwhelming and frustrating the diagnostic journey can be for families of children with developmental disorders (DD) or intellectual disabilities (ID). Developmental delays are quite common, affecting an estimated 1 in 6 children in the United States and a significant number of children who are diagnosed with DD or ID will have a genetic cause. Early evaluation and diagnosis is critical for providing timely interventions and appropriate management.
The new guidelines from the American Academy of Pediatrics (AAP), Genetic Evaluation of the Child With Intellectual Disability or Global Developmental Delay, represent a critical step forward. By recommending exome/genome sequencing as a first-tier test, we can help more families get answers faster and guide better care for their children.
Below, I’ll walk through what these guidelines mean for both healthcare providers and families.
What are the new AAP recommendations for testing children with developmental disorders?
The AAP now recommends that exome or genome sequencing be considered as a first-tier test for children with developmental disorders or intellectual disability. This replaces the older, stepwise approach of starting with single-gene testing or chromosomal microarrays and only moving to sequencing later.
What is exome and genome sequencing?
Exome sequencing looks at all the protein-coding regions (about 1% of the genome) of a person’s DNA—where most known disease-causing changes are found. Genome sequencing analyzes the entire DNA sequence, including both coding and noncoding regions, providing the most comprehensive genetic information.
How are the new guidelines on genetic testing for developmental delays different from what was recommended before?
Historically, testing followed a stepwise model:
- Single-gene tests when a specific disorder was suspected
- Chromosomal microarray testing to look for large genetic changes
- Exome or genome sequencing only after other tests were negative
The new guidance flips that approach. Starting with genome or exome sequencing saves time, reduces the need for multiple tests, and increases the chance of finding a diagnosis.
What counts as developmental delay or intellectual disability?
Developmental delay refers to when a child takes longer than expected to reach milestones such as walking, talking, or social interaction. Intellectual disability describes more significant challenges in learning and daily functioning. Examples of conditions where these concerns arise include:
- Autism spectrum disorder with developmental delay
- Fragile X syndrome
- Rett syndrome
- Epileptic encephalopathies
- Metabolic or genetic syndromes affecting brain development
Why is first-line exome and genome sequencing better for families?
Comprehensive sequencing as a first test for developmental delays and intellectual disability offers several advantages:
- Faster answers—reducing the long wait for a diagnosis
- Fewer procedures—avoiding multiple blood draws and office visits
- Greater detection power—finding genetic causes missed by older tests and less comprehensive
- Better care planning—a precise diagnosis informs prognosis, earlier treatment, and family support
Will insurance cover the cost of exome and genome sequencing?
While many insurers already cover exome sequencing in certain cases, it may take time for all payers to update their policies to align with these new guidelines. Families may still need support with prior authorizations or appeals, but coverage is expected to expand as the evidence and recommendations continue to grow.
How can Genome Medical help?
At Genome Medical, we’ve long advocated for exome and genome sequencing as a frontline test for children with developmental disorders and intellectual disabilities. Our team of geneticists and genetic counselors have deep expertise in pediatric genetics. We can:
- Provide expert counseling to help families understand their options
- Order and coordinate genetic testing, as medically necessary
- Offer guidance once results are available
We’re excited to see the field advancing toward the approach we’ve always believed best serves patients.
These new AAP guidelines are a landmark moment in pediatric genetics. By moving exome and genome sequencing forward in the genetic work-up, we can shorten the diagnostic journey for families and empower clinicians to provide more precise, informed care.
We’re proud to be at the forefront of this shift—delivering expert guidance, compassionate counseling, and responsible access to clinical genetic testing to children and families who deserve answers sooner.
Written by Brian Kirmse, MD, Medical Director at Genome Medical with an editorial boost from AI. The author provided expertise, ensured accuracy, and approved the final version.
