RT Journal Article SR Electronic T1 Electrophysiological Properties of Mutant Nav1.7 Sodium Channels in a Painful Inherited Neuropathy JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 8232 OP 8236 DO 10.1523/JNEUROSCI.2695-04.2004 VO 24 IS 38 A1 Theodore R. Cummins A1 Sulayman D. Dib-Hajj A1 Stephen G. Waxman YR 2004 UL http://www.jneurosci.org/content/24/38/8232.abstract AB Although the physiological basis of erythermalgia, an autosomal dominant painful neuropathy characterized by redness of the skin and intermittent burning sensation of extremities, is not known, two mutations of Nav1.7, a sodium channel that produces a tetrodotoxin-sensitive, fast-inactivating current that is preferentially expressed in dorsal root ganglia (DRG) and sympathetic ganglia neurons, have recently been identified in patients with primary erythermalgia. Nav1.7 is preferentially expressed in small-diameter DRG neurons, most of which are nociceptors, and is characterized by slow recovery from inactivation and by slow closed-state inactivation that results in relatively large responses to small, subthreshold depolarizations. Here we show that these mutations in Nav1.7 produce a hyperpolarizing shift in activation and slow deactivation. We also show that these mutations cause an increase in amplitude of the current produced by Nav1.7 in response to slow, small depolarizations. These observations provide the first demonstration of altered sodium channel function associated with an inherited painful neuropathy and suggest that these physiological changes, which confer hyperexcitability on peripheral sensory and sympathetic neurons, contribute to symptom production in hereditary erythermalgia.