Hereditary Angioedema with Normal C1 Inhibitor: Update on Evaluation and Treatment

Abstract

A new form of hereditary angioedema (HAE) was identified in the year 2000. Its clinical appearance resembles HAE types I and II, which are caused by mutations that result in a deficiency of C1 inhibitor (C1-INH). In patients with the new form of HAE, C1-INH plasma levels and function values are normal, so it's termed HAE with normal C1-INH (HAE-nC1). HAE-nC1, in a subgroup of patients, is thought to be caused by mutations that affect the F12 gene. The diagnosis of HAE-nC1 is based on history and clinical criteria. There are no licensed drugs with proven treatment effects for HAE-nC1. © 2017 Elsevier Inc.