Neurodevelopmental Disorders

American Epilepsy Society (AES) endorsed new practice guidelines from the National Society of Genetic Counselors (NSGC) released in October of 2022 recommending Exome Sequencing as a first-tier test for all individuals with unexplained epilepsy.

Many hundreds of genes are now known to cause neurodevelopmental disorders with a broad range of clinical presentations and levels of severity. Delayed and incorrect diagnoses are too common, impacting 44% of patients with neurological disorders.[1] Identifying the genetic cause for neurodevelopmental disorders that are diagnosed in childhood is critical for accurate diagnosis and subsequent care.

To determine these genetic diagnoses early and cost-effectively, exome sequencing is specifically recommended for children with global developmental delays or intellectual disability and is warranted for patients with other neurodevelopmental diagnoses, such as autism spectrum disorder, epilepsy, and cerebral palsy.[2] Comprehensive genetic testing via exome sequencing can identify genetic etiologies in up to 40% of patients.[1-2]

Get superior diagnostic yield with exome testing

Old testing strategies (predominantly chromosomal microarray or gene panels) can potentially delay diagnosis in a significant number of patients. Comprehensive exome sequencing assesses both sequence and copy number variants and can provide a genetic diagnosis quickly and efficiently. The diagnostic yield of traditional exome sequencing, which identifies sequence-level DNA changes across ~20,000 genes, is more than twice the yield of copy number variants (CNVs) identified by chromosomal microarray (40% vs. 15-20%) and ~100x the yield of FMR1 analysis.[3-4]


FMR1 Diagnostic Yield

<15 - 20%[3]

CMA Diagnostic Yield


Exome Diagnostic Yield

Delivering genetic diagnoses for children with global developmental delays or intellectual disability means they can end their diagnostic journey, connect with support and advocacy communities and get the specialized care they need earlier. Genetic testing can significantly reduce the length of diagnostic odyssey by 5 to 30 years.[5] Choose comprehensive genetic testing via exome sequencing.



See how XomeDx can fit your diagnostic needs today

As the industry leader in clinical exome sequencing with over 20 years of experience, we offer greater diagnostic accuracy, fewer variants of uncertain significance (VUS) and data backed answers for your patients. XomeDx goes beyond identifying sequence variants and includes comprehensive CNV-analysis. CNV detection in conjunction with analysis of sequence variants effectively  replaces the need for chromosomal microarray and offers a more synergistic analysis of each patient’s unique genetic information.

To ensure every patient can benefit from the ongoing growth of genomic knowledge, We offer a one-time, complimentary re-analysis of exome data - without requiring a new patient sample.


Request Sample Kits

Trio-based analysis is available for all test options. Providing samples of one or both biological parents (duo- or trio-testing), or other close relatives such as siblings, can improve the diagnostic yield and reduce clinical follow-up needs*.

Ready to order?

Order online through the GeneDx Provider Portal

The provider portal provides access to an efficient, secure, and HIPAA-compliant way for healthcare providers to order tests, track order status, access payment and insurance information, and access patient test results.

Paper Order with Test Requisition Form (TRF)

TRFs offer the option to print and fill out a paper order form to send in with your patient’s sample. TRFs collect patient information, informed consent, and test-specific data from providers to begin the testing process for patients.

Patient Stories

Genetic testing offers accurate diagnoses to patients and families searching for answers. Multiple case studies have demonstrated not only the clinical utility of genetic testing for patients with neurodevelopmental disorders, but the benefits it can offer to families and providers. In fact, families rarely decline diagnostic tests with 75% being in favor.[1]

Meet E.

E is a 10-year-old girl, diagnosed with global developmental delay. Despite multiple visits to various specialists and costly tests, including a CMA, her providers were not able to pinpoint the cause of her condition.

At the age of 9, the severity of her symptoms intensified. Eventually E’s clinical care team ordered an exome test. Exome testing was able to pinpoint the root cause of E’s symptoms – a de novo pathogenic variant in a gene called SETD5. This gene variant explained E’s condition and gave her family the clarity and answers they had been looking for, for a decade.

Meet S.

S, a 12-year-old boy was diagnosed with autism spectrum disorder, seizure disorder, cerebral palsy, and intellectual disability. At the age of 10, S was able to receive exome sequencing, which revealed a pathogenic de novo variant in STXBP1, finally offering an explanation for S’s symptoms. STXBP1 is associated with developmental and epileptic encephalopathy and was consistent with S’s symptoms presentation. This result provided a unifying diagnosis for his various clinical diagnoses and opened up care options for S.

Thousands of families are searching for answers on diagnostic odysseys. Exome sequencing (XomeDx) can help.

The Research Agrees – Start with Exome

Manickam et al: "ACMG Recommends Exome for GDD/ID

ACMG recommends that ES/GS be considered as a first - or second-tier test for patients with congenital nomalies/developmental delay/or intellectual disabilities.


Srivastava et al: "Consensus statement points to exome as a first-tier test"

Exome sequencing is a first-tier clinical diagnostic test for individuals with neurodevelopmental disorders, including global developmental delay, intellectual disability, and/or autism spectrum disorder and has an overall yield of 36%. The yield for isolated NDD was 31% and for NDD plus other features it was 53%


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  1. Published 2022. Accessed May 25, 2022.
  2. Manickam K, McClain MR, Demmer LA, et al. Exome and genome sequencing for pediatric patients with congenital anomalies or intellectual disability: an evidence-based clinical guideline of the American College of Medical Genetics and Genomics (ACMG). Genet Med. 2021;23(11):2029-2037. doi: 10.1038/s41436-021-01242
  3. Savatt JM, Myers SM. Genetic Testing in Neurodevelopmental Disorders. FrontPediatr. 2021 Feb 19;9:526779. doi: 10.3389/fped.2021.526779
  4. Srivastava S, Love-Nichols J, Dies K et al. Meta-analysis and multidisciplinary consensus statement: exome sequencing is a first-tier clinical diagnostic test for individuals with neurodevelopmental disorders. Genetics in Medicine. 2019;21(11):2413-2421. doi:10.1038/s41436-019-0554-6
  5. Eurordis. Survey of the delay in diagnosis for 8 rare diseases in Europe (EurordisCare2) Accessed March 16, 2022.


*Patients and families can also choose whether they would like additional, medically relevant genetic findings (secondary findings) to be reported, which affect about 2-3% of patients.
For illustrative purposes only.