Autosomal dominant erythermalgia associated with a novel mutation in the voltage-gated sodium channel alpha subunit Nav1.7.

BACKGROUND: Autosomal dominant primary erythermalgia is a rare disorder characterized by recurrent attacks of red, warm, and painful hands and/or feet.
OBJECTIVE: To describe the phenotypes and molecular data of a 10-member family with 5 symptomatic living patients with erythermalgia.
RESULTS: The clinical phenotype of this family was featured by episodic or continuous symmetrical red swelling, irritating warmth, and burning pain of feet and lower legs provoked or aggravated by warmth and exercise, and relief was always obtained by application of cold, such as putting feet in (ice-) cold water. The symptoms in this family were only partially controlled by analgesics and sedatives. All affected family members were heterozygous for a novel mutation (S241T) of the voltage-gated sodium channel alpha subunit Nav1.7.
CONCLUSION: Primary erythermalgia may be a neuropathic disorder of the small peripheral sensory and sympathetic neurons, and may be caused by hyperexcitability of Nav1.7.