SCN1B and idiopathic generalized epilepsy: Hereditary epilepsy is linked to mutations in genes producing the voltage-gated sodium channel subunit beta1 (SCN1B) and SCN2A. Generalized epilepsy with febrile seizures involves mutations in sodium channel subunits SCN1A and SCN2A, as well as the GABAA receptor subunit GABRG2. Another form of generalized epilepsy caused by a single gene mutation is benign familial newborn convulsions.