title: Hereditary angioedema with normal C1-INH (HAE type III).
abstract: Hereditary angioedema (HAE) with normal C1 inhibitor (C1-INH), also known as HAE type III, is a familial condition only clinically recognized within the past three decades. Similar to HAE from C1-INH deficiency (HAE types I and II), affected individuals experience unpredictable angioedema episodes of the skin, gastrointestinal tract, and airway. Unique clinical features of HAE with normal C1-INH include the predominance of affected women, frequent exacerbation by estrogen, and a prominence of angioedema that involves the face and oropharynx. The underlying pathophysiology of HAE with normal C1-INH is poorly understood, but indirect evidence points to contact pathway dysregulation with bradykinin-mediated angioedema. Currently, evaluation is complicated by a lack of confirmatory laboratory testing such that clinical criteria must often be used to make the diagnosis of HAE with normal C1-INH. Factor XII mutations have been identified in only a minority of persons affected by HAE with normal C1-INH, limiting the utility of such analysis. To date, no controlled clinical studies have examined the efficacy of therapeutic agents for HAE with normal C1-INH, although published evidence supports frequent clinical benefit with medications shown effective in HAE due to C1-INH deficiency.
authors.affiliation: Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, Calif. Electronic address: mriedl@ucsd.edu.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Riedl
mesh_terms: D003174:Complement C1 Inactivator Proteins / Q000235:genetics; D050718:Complement C1 Inhibitor Protein; D056828:Hereditary Angioedema Type III / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism; D006801:Humans
chemical_list: D003174:Complement C1 Inactivator Proteins; D050718:Complement C1 Inhibitor Protein; C469952:SERPING1 protein, human
keywords: Hereditary angioedema; diagnosis; estrogen; factor XII mutation; normal C1-INH; treatment; type III