We report for the first time in Brazil a mutation in the F12 gene as a likely cause of HAE with normal C1-INH in patients with recurrent attacks of angioedema and/or abdominal pain.
Hereditary angioedema (HAE) due to C1 inhibitor (C1-INH) deficiency is a rare genetic disease characterized by recurrent swellings of the subcutaneous and submucosal tissues that can manifest as cutaneous edema, abdominal pain and laryngeal edema with airway obstruction.
The clinical features of C1-INH deficiencies are the same in both forms of angioedema, and include subcutaneous non-pruritic swelling, the involvement of the upper respiratory tract, and abdominal pain due to partial obstruction of the gastrointestinal tract; however, AAE patients have no family history of angioedema and are characterised by the late onset of symptoms.
We describe a case of type I hereditary angioedema (a quantitative deficit of C1 inhibitor), the sole initial symptom of which was severe recurrent and self-limited abdominal pain, accompanied by ascites during these episodes.