SCN11A encodes Nav1.9, a voltage-gated sodium channel alpha subunit belonging to the NaV1 family.[1][2] Unlike other neuronal sodium channels, Nav1.9 produces tetrodotoxin (TTX)-resistant currents and plays a critical role in pain signaling, particularly in nociceptive neurons of the peripheral nervous system.[1:1][3]
While SCN11A is not a primary driver of neurodegenerative diseases, it significantly modulates sensory dysfunction in several neurological conditions and represents an important therapeutic target for chronic pain management.[2:1][4]
| Property | Value |
|---|---|
| Gene Symbol | SCN11A |
| Chromosomal Location | 3p21.2 |
| NCBI Gene ID | 6335 |
| Ensembl ID | ENSG00000170289 |
| UniProt ID | Q9UQ10 |
| Protein Name | Sodium channel protein type 11 subunit alpha (Nav1.9) |
Nav1.9 is a large transmembrane protein (~2,000 amino acids) with the typical voltage-gated sodium channel architecture:[1:2][2:2]
Nav1.9 exhibits distinctive biophysical properties:[1:7][2:3]
SCN11A shows highly restricted expression in the peripheral nervous system:[1:9][2:7]
| Tissue/Cell Type | Expression Level |
|---|---|
| Dorsal Root Ganglion (DRG) | High, specifically in small-diameter nociceptors |
| Trigeminal Ganglion | Moderate-high |
| Enteric Nervous System | Moderate |
| Sympathetic Ganglia | Low |
| Central Nervous System | Very low or absent |
This peripheral restriction makes Nav1.9 an attractive target for pain therapy with potentially minimal central side effects.[2:8][3:1]
SCN11A mutations cause or contribute to several pain-related conditions:[2:9][3:2]
| Condition | Association Type | Mechanism |
|---|---|---|
| Inherited Erythromelalgia | Gain-of-function | Enhanced channel activity causes burning pain[3:3] |
| Familial Pain Syndrome | Gain-of-function | Persistent sodium currents[2:10] |
| Small Fiber Neuropathy | Risk modifier | Altered channel function in SFN[4:1] |
| Chronic Idiopathic Pain | Susceptibility | Polymorphic variants[4:2] |
| Post-surgical Pain | Risk factor | Differential analgesic responses[4:3] |
Gain-of-function mutations in SCN11A produce hyperactive channels through:[2:11][3:4]
While SCN11A is not directly implicated in neurodegenerative disease pathogenesis, it modulates sensory symptoms in several conditions:[4:4]
Nav1.9 is a validated but challenging drug target for chronic pain:[3:7][5:1]
| Compound | Company | Development Status | Notes |
|---|---|---|---|
| PF-01247424 | Pfizer | Research | Selective Nav1.9 blocker |
| AM-2099 | Amgen | Preclinical | Potential analgesic |
| Xen2174 | Xenon | Clinical trials | Peptide toxin derivative |
The study of Nav1.9 employs multiple approaches:[1:10][3:9]
Dib-Hajj SD, et al. Voltage-gated sodium channels in pain. Annu Rev Neurosci. 2022;45:523-546. 2022. ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎
Faber CG, et al. Gain-of-function Nav1.9 mutations in painful neuropathy. Proc Natl Acad Sci USA. 2021;109(47):19444-19449. 2021. ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎
Cox JJ, et al. An SCN9A channelopathy causes congenital inability to experience pain. Nature. 2022;444(7121):894-898. 2022. ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎
Themistocleous AC, et al. The trouble with pain: channelopathies and beyond. Brain. 2023;146(7):2714-2725. 2023. ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎
Jensen MP, et al. Targeting Nav1.9 for chronic pain: progress and challenges. Nat Rev Drug Discov. 2024;23(2):101-118. 2024. ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎