SERPING1 and angioedema: Hereditary angioedem (HAE) a due to C1 inhibitor (C1-INH) deficiency (C1-INH-HAE), a type of bradykinin (BK)-mediated angioedema, is a rare autosomal dominant inherited disorder characterized by intermittent, unpredictable swelling of subcutaneous and/or submucosal tissues.