To date, eight different genes causing HAE in an autosomal dominant manner have been described: SERPING1 (HAE-C1-INH) (5), F12 (HAE-F12) (6), PLG (HAE-PLG) (7), ANGPT1 (HAE-ANGPT1) (8), KNG1 (HAE-KNG1) (9), MYOF (HAE-MYOF) (10), HS3ST6 (HAE-HS3ST6) (11), DAB2IP (HAE-DAB2IP) (12); and, recently, CPN1 has been reported as the first gene causing HAE in an autosomal recessive inheritance pattern (HAE-CPN1) (13). The gene discussed is PLG; the disease is hereditary angioedema.