KNG1 and hereditary angioedema: ,3 Although the exact prevalence of HAE-C1INH remains difficult to verify, HAE-nC1INH is expected to be at least several times less frequent than HAE-C1INH.5, 6, 7 HAE-nC1INH can be classified based on the causative genes; mutations in blood clotting factor XII (F12), angiopoietin-1 (ANGPT-1), plasminogen (PLG), kininogen 1 (KNG1), myoferlin (MYOF), and heparan sulfate 3-O-sulfotransferase 6 (HS3ST6) genes are known to be associated with HAE-nC1INH.1