A cost-effective algorithm for diagnosis of hereditary angioedema with normal C1 inhibitor: Applying molecular approach to clinical practice

Abstract

Hereditary angioedema (HAE) is an autosomal-dominant disease characterized by recurrent edema of subcutaneous tissue, gastrointestinal tract, and upper airways.1 Over a decade ago, HAE with normal C1 inhibitor (C1-INH) has been described, associated with mutations in F12, the gene encoding coagulation factor XII (FXII).2 Subsequently, mutations in Plasminogen (PLG), Angiopoietin-1 (ANGPT1), and Kininogen 1 (KNG1) genes have been reported as cause of HAE with normal C1-INH.3-5 The newly described KNG1 mutation could lead to a functionally active but aberrant bradykinin, which would undergo modified inactivation resulting in prolonged half-life.