Heterozygous missense mutations in several other voltage-gated sodium channel genes have been associated with BrS (SCN5A: MIM 600163), familial episodic pain syndrome FEPS3 (SCN11A; MIM 604385), primary erythermalgia, and paroxysmal extreme pain disorder (SCN9A; MIM 603415). The gene discussed is SCN9A; the disease is paroxysmal extreme pain disorder.