SCN1A and epilepsy: Voltage-gated sodium channel gene mutations may participate in the occurrence of epilepsy, thus affecting the response of individuals to antiepileptic drugs.[21,22] Voltage-gated sodium channel consists of one α subunit and several β subunits, in which α subunit is the main structural and functional unit.[23] Mutations in SCN1A and SCN2A genes of α subunit are associated with epilepsy in children.[24,25] VPA may play an antiepileptic role by blocking sodium channels.