Hereditary angio-oedema with normal C1-INH, developing recurrent acute abdomen after taking low-dose oestrogen-progestin: A case report.

Hereditary angio-oedema (HAE) is a rare genetic disease characterised by repeated episodes of temporary organ swelling. Three types of HAE are known, of which HAE with normal C1 inactivator is difficult to be diagnosed due to its lack of laboratory abnormalities. Here, we describe a case of HAE with normal C1 inactivator and recurrent acute abdomen following low-dose oestrogen-progestin therapy. Notably, genetic analysis by Sanger sequencing led to the identification of a recurrent heterozygous missense mutation c.988A > G (p.K330E) in the plasminogen (PLG) gene of the patient. Prophylactic tranexamic acid and on-demand selective bradykinin B2 receptor blockers are used to treat her symptoms.