C1-INH-HAE (types I and II) are mainly caused by pathogenic variations of SERPING1 that results in deficient or dysfunctional C1-INH, kinin, and/or contact system dysregulation, leading to overproduction of bradykinin, localised vasodilatation, vascular leakage, and the development of massive local oedema [1, 2, 11]. This evidence concerns the gene SERPING1 and hereditary angioedema.