SCN1B-related disorder is often characterized by epilepsy, however the type of epilepsy is broad and can range from: Febrile seizures, GEFS+, early absence epilepsy, Epilepys with Myoclonic-Atonic Seizures (EMAS), to Developmental and Epileptic Encephalopathy (DEE) and Dravet Syndrome-like phenotypes. Given these wide categories, multiple seizure types as well as age of presentations are possible. A spectrum of developmental impairment is also seen from normal intellect (febrile seizures/GEFS+) to severe developmental delay and intellectual disability (DEE/Dravet Syndrome-like phenotypes). In addition to seizures and developmental delay, cardiac arrhythmias can also be seen such as Brugada Syndrome or atrial fibrillation. Certain variants can cause an isolated cardiac arrhythmia phenotype while others result in both seizures and cardiac arrhythmias.
SCN1B