National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

SCN8A encephalopathy


Other Names:
Early infantile epileptic encephalopathy-13; Epileptic Encephalopathy, early infantile, 13; EIEE13; Early infantile epileptic encephalopathy-13; Epileptic Encephalopathy, early infantile, 13; EIEE13; SCN8A epilepsy See More
This disease is grouped under:
SCN8A encephalopathy is a very rare form of early-onset epilepsy that causes multiple types of seizures and developmental delay or regression (loss of skills).[1] Seizures begin during the first 18 months of life, at an average age of 4 months. Types of seizures may include generalized tonic-clonic seizures, infantile spasms, absence seizures, and focal seizures. Other signs and symptoms of SCN8A encephalopathy may include low muscle tone (hypotonia), a high pain tolerance, movement disorders (such as dystonia and ataxia), mild to severe intellectual disability, sleep problems, and autistic-like features.[1][2][3][4] In some people with SCN8A encephalopathy, various other medical problems have been reported including hearing or vision problems, scoliosis, and difficulty regulating body temperature. About 10% of people with SCN8A encephalopathy reported in the literature have died from sudden unexpected death in epilepsy (SUDEP).[2]

SCN8A encephalopathy is caused by mutations in the SCN8A gene. Inheritance is autosomal dominant, but most people with SCN8A encephalopathy have a new mutation in the gene that was not inherited from a parent.[2] Treatment aims to control seizures with medications, which is extremely challenging. Seizure control should be managed by a pediatric neurologist with expertise in epilepsy who is familiar with SCN8A encephalopathy.[2]
Last updated: 4/23/2018

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
5%-29% of people have these symptoms
Cerebral atrophy
Degeneration of cerebrum
0002059
Percent of people who have these symptoms is not available through HPO
Autism 0000717
Autosomal dominant inheritance 0000006
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood
[ more ] 		0002376
Epileptic encephalopathy 0200134
Epileptic spasm 0011097
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ] 		0001290
Global developmental delay 0001263
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Progressive microcephaly
Progressively abnormally small cranium
Progressively abnormally small skull
[ more ] 		0000253
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Patient Registry

  • A registry supports research by collecting of information about patients that share something in common, such as being diagnosed with SCN8A encephalopathy. The type of data collected can vary from registry to registry and is based on the goals and purpose of that registry. Some registries collect contact information while others collect more detailed medical information. Learn more about registries.

    Registries for SCN8A encephalopathy:
    International Ion Channel Epilepsy Patient Registry
    SCN8A Registry
     

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Helbig E. SCN8A encephalopathy – and how it differs from Dravet Syndrome. International League Against Epilepsy (ILAE). January 13, 2015; http://epilepsygenetics.net/2015/01/13/scn8a-encephalopathy-and-how-it-differs-from-dravet-syndrome.
  2. Hammer MF, Wagnon JL, Mefford HC, Meisler MH. SCN8A-Related Epilepsy with Encephalopathy. GeneReviews. August 25, 2016; https://www.ncbi.nlm.nih.gov/books/NBK379665/.
  3. Larsen J & cols. The phenotypic spectrum of SCN8A encephalopathy. Neurology. 2015; 84(5):480-489. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4336074.
  4. About SCN8A Epilepsy. The Cute Syndrome Foundation. http://www.thecutesyndrome.com/scn8a.html.