SCN1A

Voltage-dependent sodium channels are heteromeric complexes that regulate sodium exchange between intracellular and extracellular spaces and are essential for the generation and propagation of action potentials in muscle cells and neurons. Each sodium channel is composed of a large pore-forming, glycosylated alpha subunit and two smaller beta subunits. This gene encodes a sodium channel alpha subunit, which has four homologous domains, each of which contains six transmembrane regions. Allelic variants of this gene are associated with generalized epilepsy with febrile seizures and epileptic encephalopathy. Alternative splicing results in multiple transcript variants. The RefSeq Project has decided to create four representative RefSeq records. Three of the transcript variants are supported by experimental evidence and the fourth contains alternate 5' untranslated exons, the exact combination of which have not been experimentally confirmed for the full-length transcript. [provided by RefSeq, Oct 2015]

Sodium Voltage-Gated Channel Alpha Subunit 1

Mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a sodium-selective channel through which Na+ ions may pass in accordance with their electrochemical gradient. Plays a key role in brain, probably by regulating the moment when neurotransmitters are released in neurons. Involved in sensory perception of mechanical pain: activation in somatosensory neurons induces pain without neurogenic inflammation and produces hypersensitivity to mechanical, but not thermal stimuli.

Biological Process adult walking behaviorIEA:Ensembl
Biological Process cardiac muscle cell action potential involved in contractionManual Assertion Based On ExperimentIMP:BHF-UCL
Biological Process detection of mechanical stimulus involved in sensory perception of painISS:UniProtKB
Biological Process establishment of localization in cellIEA:Ensembl
Biological Process membrane depolarization during action potentialManual Assertion Based On ExperimentIBA:GO_Central
Biological Process neuromuscular process controlling postureIEA:Ensembl
Biological Process neuronal action potentialManual Assertion Based On ExperimentIBA:GO_Central
Biological Process neuronal action potential propagationIEA:Ensembl
Biological Process regulation of ion transmembrane transportIEA:UniProtKB-KW
Biological Process sodium ion transmembrane transportManual Assertion Based On ExperimentIBA:GO_Central
Biological Process sodium ion transportISS:UniProtKB

Cell membrane

Generalized epilepsy with febrile seizures plus 2 (GEFS+2):
A rare autosomal dominant, familial condition with incomplete penetrance and large intrafamilial variability. Patients display febrile seizures persisting sometimes beyond the age of 6 years and/or a variety of afebrile seizure types. This disease combines febrile seizures, generalized seizures often precipitated by fever at age 6 years or more, and partial seizures, with a variable degree of severity.
Dravet syndrome (DRVT):
A severe form of epileptic encephalopathy characterized by generalized tonic, clonic, and tonic-clonic seizures that are initially induced by fever and begin during the first year of life. Later, patients also manifest other seizure types, including absence, myoclonic, and simple and complex partial seizures. Psychomotor development delay is observed around the second year of life. Some patients manifest a borderline disease phenotype and do not necessarily fulfill all diagnostic criteria for core DRVT. DRVT is considered to be the most severe phenotype within the spectrum of generalized epilepsies with febrile seizures-plus.
Intractable childhood epilepsy with generalized tonic-clonic seizures (ICEGTC):
A disorder characterized by generalized tonic-clonic seizures beginning usually in infancy and induced by fever. Seizures are associated with subsequent mental decline, as well as ataxia or hypotonia. ICEGTC is similar to SMEI, except for the absence of myoclonic seizures.
Migraine, familial hemiplegic, 3 (FHM3):
A subtype of migraine associated with transient blindness in some families. Migraine is a disabling symptom complex of periodic headaches, usually temporal and unilateral. Headaches are often accompanied by irritability, nausea, vomiting and photophobia, preceded by constriction of the cranial arteries. The two major subtypes are common migraine (migraine without aura) and classic migraine (migraine with aura). Classic migraine is characterized by recurrent attacks of reversible neurological symptoms (aura) that precede or accompany the headache. Aura may include a combination of sensory disturbances, such as blurred vision, hallucinations, vertigo, numbness and difficulty in concentrating and speaking.
Febrile seizures, familial, 3A (FEB3A):
Seizures associated with febrile episodes in childhood without any evidence of intracranial infection or defined pathologic or traumatic cause. It is a common condition, affecting 2-5% of children aged 3 months to 5 years. The majority are simple febrile seizures (generally defined as generalized onset, single seizures with a duration of less than 30 minutes). Complex febrile seizures are characterized by focal onset, duration greater than 30 minutes, and/or more than one seizure in a 24 hour period. The likelihood of developing epilepsy following simple febrile seizures is low. Complex febrile seizures are associated with a moderately increased incidence of epilepsy.
Developmental and epileptic encephalopathy 6B (DEE6B):
A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE6B is an autosomal dominant condition characterized by onset of seizures in early infancy, profoundly impaired intellectual development, and a hyperkinetic movement disorder.

Phosphorylation at Ser-1516 by PKC in a highly conserved cytoplasmic loop slows inactivation of the sodium channel and reduces peak sodium currents.