SCN4B
Sodium Voltage-Gated Channel Beta Subunit 4
Gene Information Card
| Symbol | SCN4B |
|---|---|
| Full Name | Sodium Voltage-Gated Channel Beta Subunit 4 |
| Gene Type | protein-coding |
| Chromosomal Location | 11q23.3 |
| NCBI Gene ID | 6330 ncbi.nlm.nih.gov/gene/6330 |
| Ensembl ID | ENSG00000177098 |
| UniProt ID | Q8IWT1 |
| OMIM ID | 608256 |
| HGNC ID | 10593 |
| Aliases | Navβ4, ATFB17, LQT10, BRGDA7 |
Description
SCN4B encodes the beta-4 subunit (Navβ4) of voltage-gated sodium channels. This auxiliary subunit modulates channel gating kinetics, voltage dependence, and cell surface expression. It is predominantly expressed in heart, skeletal muscle, and brain. Mutations in SCN4B are associated with cardiac arrhythmias including long QT syndrome type 10 (LQT10) and Brugada syndrome type 7 (BRGDA7).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Long QT syndrome 10 (LQT10) | Loss-of-function mutation reduces sodium current, prolonging cardiac repolarization | OMIM #608256; ClinVar |
| Brugada syndrome 7 (BRGDA7) | Altered channel gating leads to reduced sodium current and ST-segment elevation | OMIM #613120; ClinVar |
| Atrial fibrillation (ATFB17) | Variant may disrupt sodium channel function in atrial myocytes | OMIM #615377; ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 12.5 | Medium |
| Skeletal muscle | 8.3 | Low |
| Brain | 6.1 | Low |
| Kidney | 3.2 | Not detected |
| Liver | 1.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Cardiomyocytes (iPS-derived) | 15.2 | High expression |
| SH-SY5Y (neuroblastoma) | 7.8 | Moderate expression |
| HEK293 | 2.3 | Low expression |
| HeLa | 0.9 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.448G>A (p.Glu150Lys) | Missense | Rare | Loss of function; associated with LQT10 |
| c.538C>T (p.Arg180Trp) | Missense | Rare | Gain of function; associated with BRGDA7 |
| c.1A>G (p.Met1Val) | Start loss | Very rare | Loss of function; likely pathogenic |
Mutation functional classification
Loss of Function (LOF)
Reduced sodium current density or altered channel gating, leading to prolonged repolarization (LQT10).
Gain of Function (GOF)
Enhanced sodium current or altered inactivation, contributing to Brugada syndrome phenotype.
Dominant Negative (DN)
Not well documented for SCN4B; most mutations act via haploinsufficiency or altered gating.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Voltage-gated sodium channel pathway (Reactome: R-HSA-5576892)
• Cardiac conduction (KEGG: hsa05414)
Protein Summary
The SCN4B protein (Navβ4) is a 228-amino acid type I transmembrane protein with an extracellular immunoglobulin-like domain and a short intracellular C-terminus. It associates with the pore-forming alpha subunit (Nav1.5) to modulate channel inactivation and voltage dependence. Navβ4 is essential for normal cardiac action potential propagation and excitability.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SCN4B Knockout HEK293 Cell Line | EDJ-KQ5719 | Human | 6330 | Details Get a Quote |
| SCN4B Knockout HeLa Cell Line | EDJ-KQ54402 | Human | 6330 | Details Get a Quote |
| SCN4B Knockout A-549 Cell Line | EDJ-KQ62893 | Human | 6330 | Details Get a Quote |
| SCN4B Knockout HCT 116 Cell Line | EDJ-KQ71359 | Human | 6330 | Details Get a Quote |
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