SCN8A Epilepsy, also known as Epileptic Encephalopathy, early infantile, 13 (EIEE13), is a rare genetic condition that causes chronic seizures (epilepsy) and is caused by a change (mutation) in the SCN8A gene. Seizures seen in SCN8A epilepsy typically start at an early age, usually between birth and 18 months of age. The seizures usually include stiff muscles (tonic) and loss of consciousness followed by jerking of arms and legs as the body relaxes and the person returns to consciousness (clonic). These episodes usually last 1 to 3 minutes. Learning problems (intellectual disabilities), developmental delay, and low muscle tone (hypotonia) are also usually seen in children who have this condition.
SCN8A epilepsy is inherited in an autosomal dominant manner, meaning a mutation in one of the two copies of the SCN8A gene a child has is enough to cause the condition. However, it is believed that most cases are due to a new mutation in the affected child and not inherited from a parent. This condition is considered in children who have seizures and learning problems. The doctor may use a test called an electroencephalogram (EEG) to measure electrical activity in the brain. In SCN8A epilepsy, the EEG shows a specific suppression-burst pattern that is different than most other forms of epilepsy. Although there is not a cure for SCN8A epilepsy, anti-seizure medications may help control some of the symptoms. If your child has been diagnosed with SCN8A epilepsy, talk to their doctor about all current treatment options. Support groups are a good resource for additional information and to connect with other families affected by this condition.