Hereditary angioedema (HAE) caused by C1-esterase inhibitor deficiency is anautosomal-dominant disease resulting from a mutation in the C1-inhibitor gene.HAE is characterized by recurrent attacks of intense, massive, localizedsubcutaneous edema involving the extremities, genitalia, face, or trunk, orsubmucosal edema of upper airway or bowels. Here, C1S is linked to hereditary angioedema.