Frequently Asked Questions
1 in 26 people will have epilepsy in their lifetime making it is the fourth most common neurological disorder in the world. Epilepsy is diagnosed when someone has 2 or more unprovoked seizures.
Seizures are sudden surges of uncontrolled electrical activity in the brain that disrupt the way messages are sent between brain cells. There are many different types of seizures. It is important to understand what type of seizure someone is having as it may change the type of medication your doctor may prescribe. You can learn more about the different types of seizures here.
SCN8A epilepsy is a a rare syndrome that often manifests in difficult to treat epilepsy beginning in early life and significantly impacting development and quality of life. We are learning that there are many different forms of SCN8A that lead to different kinds of seizures, levels of development and response to medications. You can learn much more about the different forms of SCN8A on our About SCN8A page.
While we have about 600 cases in our Registry and analysis study, we estimate that over 700 people have been diagnosed with SCN8A globally. Roughly one in every 60,000 people are estimated to have a disease-causing SCN8A mutation, so there are many more people out there than have yet to be diagnosed.
There is a wide spectrum of how people with SCN8A are affected, but there are 5 distinct subgroups: No epilepsy, behavioral or movement disorders; benign familial epilepsy; mild developmental and epileptic encephalopathy (DEE); moderate DEE; and severe DEE. People who fall in the more severe categories are more likely to have seizures, limited mobility, and sleep difficulties. For people who don’t have seizures, they may be more likely to have delayed development of speech, movement, and overall brain function. You can learn more on on our About SCN8A page.
The International SCN8A Alliance is working with urgency to advance efforts to find a cure by working collaboratively with global SCN8A partner organizations, researchers, clinicians and pharmaceutical companies.
As of right now, there are no medications targeting SCN8A specifically. That means that those diagnosed with SCN8A are treated with seizure medications that are considered more general or for specific seizure symptoms or types (i.e. focal seizure, tonic-clonic – formerly called grand mal seizure, or tonic seizure).
How SCN8A is treated should depend on the kind of SCN8A someone is diagnosed with, functionally. There are both gain-of-function and loss-of-function variants, each of which have different kinds of anti seizure meds that help control the seizures.
In general, those with gain-of-function variants will have better results with sodium-channel blockers as these help stem the flow of excess sodium into the neurons. And in general, those with loss-of-function variants do poorly on sodium channel blockers as the flow of sodium into the neurons is already too low. They tend to do better with medications that treat the specific seizures they are having, such as ethosuximide for absence seizures.
To learn more about these, please reference the illustrations and information available on our What is SCN8A? page.
Because SCN8A syndrome is caused by changes in the genetic code, diagnosis of SCN8A requires genetic testing.
SCN8A is primarily caused by a de novo mutation, meaning that the changes to this gene happen randomly. However, there are some cases of SCN8A that has been inherited from a parent with SCN8A. We are still learning more about these cases and hope to better document and learn from them.
In a 2018 paper submitted by SCN8A researchers Elena Gardella, Katrine Johannesen, Katherine Howell, and Douglas Smith, the mortality rate observed was 4.8% . Of 185 SCN8A patients that were followed, 9 died. Sudden Unexpected Death in Epilepsy (SUDEP) occurred in 3 of these patients. We are still working to understand the overall risks associated with SCN8A but encourage all families to discuss prognosis and SUDEP with their doctors. You can learn more about SUDEP at our partner project, DEE-P Connections.