Factsheet
Condition:
Hereditary angioedema
Inheritance:
Autosomal dominant
Genetic Etiology:
Mutation in C1NH gene, encoding complement C1 inhibitor gene
Frequency:
1/50,000
Clinical features:
Affected individuals have episodes of edema, particularly involving the extremities, nasopharynx and larynx, along with symptoms of abdominal pain, diarrhea, and vomiting. It is associated with C1 esterase inhibitor deficiency, leading to activation of the complement pathway.
Management:
Prophylaxis of attacks by treatment with attenuated androgens (e.g. Danazol), or antifibronolytic agents (e.g. epsilon-aminocaproic acid). Infusion of C1 inhibitor concentrate can be administered for prophylaxis at times of high risk, as before surgical procedures. Acute attacks may be treated with attenuated androgens or infusion of C1 inhibitor.
Genetic counseling:
Based on autosomal dominant inheritance; genetic testing is available.