Contributes to voltage-gated sodium channel activity. Predicted to be involved in membrane depolarization during action potential; neuronal action potential; and sodium ion transmembrane transport. Predicted to act upstream of or within monoatomic ion transmembrane transport and sodium ion transport. Predicted to be located in plasma membrane. Predicted to be part of voltage-gated sodium channel complex. Predicted to be active in axon. Is expressed in heart; nervous system; and neural tube. Used to study Dravet syndrome. Human ortholog(s) of this gene implicated in Dravet syndrome; developmental and epileptic encephalopathy 6B; familial hemiplegic migraine 3; generalized epilepsy with febrile seizures plus; and generalized epilepsy with febrile seizures plus 2. Orthologous to several human genes including SCN7A (sodium voltage-gated channel alpha subunit 7).