It has been estimated that 5.6 to 25% of molecular variants related to HAE1 and HAE2 are the novo, making the SERPING1 gene a prime example of mutagenic lability [5, 6] Other forms of hereditary angioedema with normal-C1-Inhibitor protein levels such as HAE3 (OMIM #610618), HAE4 (OMIM #619360), HAE5 (OMIM #619361), HAE6 (OMIM #619363), HAE7 (OMIM #619366) and HAE8 (OMIM #619367), are caused by pathogenic molecular variants in the F12, PLG, ANGPT1, KNG1, MYOF and HS3ST6 genes, respectively [3]. Here, SERPING1 is linked to hereditary angioedema.