Various variants in different genes including the factor XII (F12), the plasminogen (PLG), angiopoietin-1 (ANGPT1) and kininogen-1 (KNG1) genes were identified in patients of large families with HAEnCI across 3 or more generations and were assumed to be involved in the development of types of HAE [5–10] (Table 1). Here, ANGPT1 is linked to hereditary angioedema.