immunology allergic disorders
Hereditary and Acquired Angioedema
Hereditary angioedema
Hereditary angioedema has 3 types: Type 1 (80 to 85%): Characterized byC1 inhibitordeficiency Type 2 (15 to 20%): Characterized byC1 inhibitordysfunction Type 3 (rare): Characterized by normalC1 inhibitorfunction and levels Type 1 and type 2 involve mutations of the gene encodingC1 inhibitor. Inheritance in type 1 is autosomal dominant. Clinical presentation is usually during childhood or adolescence; 75% of patients with type 1 have an episode by age 15. . Inheritance is autosomal dominant although de novo mutations occur in about 25% of cases ( General reference ). Type 3 is rare). It is characterized by normalC1 inhibitorand is sometimes due to genetic mutations that result in abnormal forms of factor XII,plasminogen, angiopoietin 1, or kininogen. Type 3 occurs more frequently in females. 