SCN3A Gene: Sodium Voltage-Gated Channel Alpha Subunit 3
Genetic insights into SCN3A-related epilepsy and neurodevelopmental disorders
Gene Information Card
| Symbol | SCN3A |
|---|---|
| Full Name | sodium voltage-gated channel alpha subunit 3 |
| Gene Type | protein-coding |
| Chromosomal Location | 2q24.3 |
| NCBI Gene ID | 6328 ncbi.nlm.nih.gov/gene/6328 |
| Ensembl ID | ENSG00000153253 |
| UniProt ID | Q9NY46 |
| OMIM ID | 182391 |
| HGNC ID | 10590 |
| Aliases | Nav1.3, SCN3A1, sodium channel protein type 3 subunit alpha |
Description
The SCN3A gene encodes the alpha subunit of a voltage-gated sodium channel (Nav1.3), which is critical for the initiation and propagation of action potentials in excitable cells, particularly neurons. It is expressed in the central nervous system and plays a role in neuronal excitability. Mutations in SCN3A are associated with a spectrum of epileptic encephalopathies and neurodevelopmental disorders, including focal epilepsy and intellectual disability.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Epileptic encephalopathy, early infantile, 1 | Gain-of-function mutations increase sodium current, leading to hyperexcitability | ClinVar, OMIM |
| Focal epilepsy with speech disorder | Missense mutations alter channel gating properties | ClinVar, OMIM |
| Neurodevelopmental disorder with or without seizures | Loss-of-function mutations impair channel function | ClinVar, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | High | High expression in cerebral cortex and hippocampus |
| Testis | Low | Low expression |
| Kidney | Low | Low expression |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | High | Neuronal-like cells |
| U-87 MG (glioblastoma) | Moderate | Glial origin |
| HEK293 (embryonic kidney) | Low | Non-neuronal |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.554G>A (p.Arg185Gln) | Missense | Rare | Gain-of-function, associated with epilepsy |
| c.673C>T (p.Arg225Cys) | Missense | Rare | Loss-of-function, linked to neurodevelopmental disorder |
| c.4465G>A (p.Val1489Met) | Missense | Rare | Uncertain significance, reported in focal epilepsy |
Mutation functional classification
Loss of Function (LOF)
Reduced sodium current, leading to hypoexcitability; associated with neurodevelopmental disorders.
Gain of Function (GOF)
Increased sodium current, causing hyperexcitability; linked to epileptic encephalopathies.
Dominant Negative (DN)
Not well-documented for SCN3A; most mutations act via gain- or loss-of-function.
View complete mutation data：
Gene Ontology (GO)
| • voltage-gated sodium channel activity | • sodium ion transmembrane transport |
| • action potential propagation | • neuronal action potential |
| • plasma membrane |
Pathways
• Voltage-gated sodium channel complex
• Ion transport
• Neuronal signaling
Protein Summary
The SCN3A protein (Nav1.3) is a pore-forming alpha subunit of a voltage-gated sodium channel. It consists of four homologous domains, each with six transmembrane segments, forming a sodium-selective pore. The channel is essential for the rapid depolarization phase of action potentials in neurons. Mutations can alter channel kinetics, affecting neuronal excitability and leading to neurological disorders.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SCN3A Knockout HEK293 Cell Line | EDJ-KQ2930 | Human | 6328 | Details Get a Quote |
| SCN3A Knockout HeLa Cell Line | EDJ-KQ54400 | Human | 6328 | Details Get a Quote |
| SCN3A Knockout A-549 Cell Line | EDJ-KQ62891 | Human | 6328 | Details Get a Quote |
| SCN3A Knockout HCT 116 Cell Line | EDJ-KQ71357 | Human | 6328 | Details Get a Quote |
| SCN3A Overexpression HEK293 Stable Cell Line | EDC90333 | Human | 6328 | Details Get a Quote |
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