This project aims to analyse in an unbiased way the existence of genetic variants that contribute to explaining and predicting the differences in clinical expression between patients with HAE.

Inclusion Criteria:

• Adult patients (≥ 18 years old) with HAE-C1INH diagnosis (confirmed by mutation in SERPING1 gen or immunochemical study showing a decrease in C1INH function <50% in two determinations together with a family history (symptomatic patients' group)
• Patients ≥ 22 years old with C1INH hereditary deficiency (confirmed by mutation of SERPING1 gene or immunochemical study showing a decrease in C1INH function <50% in two determinations together with a family history) and who have not developed symptoms consistent with HAE-C1INH
• Signed informed consent.

Exclusion Criteria:

• No confirmed C1INH deficiency.
• Inability to sign the informed consent.
• Presence of recurrent angioedema with histaminergic characteristics (response to treatment with antihistamines, glucocorticoids and/or epinephrine)

Adult patients with hereditary angioedema with C1INH deficiency (HAE-C1INH) from different regions of Spain will be included. Patients included in the study will be divided into two groups: a) symptomatic (≥ 18 years old), which will be those who present symptoms compatible with HAE-C1INH and who have a confirmed diagnosis and b) asymptomatic patients (≥ 22 years old), which will be those with a C1INH deficiency and who have not developed symptoms of HAE.