This expression pattern is consistent with the phenotypes of three inherited disorders that are caused by recently described disease-associated SCN9A mutations: autosomal dominant primary erythermalgia (PE) and paroxysmal extreme pain disorder (PEPD), and autosomal recessive channelopathy associated insensitivity to pain (CIP) [24]–[26]. The gene discussed is SCN9A; the disease is paroxysmal extreme pain disorder.