Epilepsy can have many causes. Where the cause is genetic, the culprit can be a mutation in a gene called SCN1A, which carries the blueprint for a sodium channel in nerve cells and plays a key role in transmitting electrical signals. These neurons normally act as the brain’s brakes, and when that braking system fails, neural networks can become hyperactive and trigger epileptic seizures.

Certain mutations in the SCN1A gene cause an inherited form of epilepsy known as GEFS⁺. People with GEFS⁺ suffer from febrile seizures, often beginning in early childhood. Until now, inherited epileptic disorders have been treated with epileptic drugs that reduce the frequency of seizures but often come with side effects. Additionally, not all patients respond well to current treatments.