SCN1B and developmental and epileptic encephalopathy: SCN1B is known to be associated with atrial fibrillation, familial, 13 (#615377), Brugada syndrome 5 (#612838), developmental and epileptic encephalopathy 52 (#617350), and epilepsy with febrile seizures plus and type 1 (#604233) due to the presence of pathogenic mutations.