SCN9A
MIM.603415 2q24
SCN9A is selectively expressed within nociceptive dorsal root ganglion and sympathetic ganglion neurons.
Etiology
Primary erythermalgia can be caused by mutation in the SCN9A gene (MIM.603415), encoding a voltage-gated sodium channel Na(v)1.7
- Erythermalgia is an inherited painful neuropathy. Inherited erythermalgia (also termed erythromelalgia) is characterized by severe pain in the limbs in response to mild thermal stimuli or exercise.
- Shifts in activation and deactivation, and enhanced responses to small stimuli in SCN9A mutant channels, decrease the threshold for single impulses and high-frequency trains of impulses in pain-sensing neurons.
References
Waxman SG, Dib-Hajj S. Erythermalgia: molecular basis for an inherited pain syndrome. Trends Mol Med. 2005 Dec;11(12):555-62. PMID: #16278094#