hereditary angioedema

Hereditary angioedema

Hereditary angioedema (HAE) is a rare disease that results in recurrent attacks of severe swelling. HAE affects approximately 1 in 50,000 people. The condition is typically first noticed in childhood. Several different genetic alterations can precipitate the most common form of HAE, a "genetic deficiency in C1 inhibitor". However, forms of HAE have been identified that are independent of this most common cause. The swelling most commonly affects the arms, legs, face, intestinal tract, and airway. If the intestinal tract is affected, abdominal pain, nausea and vomiting may occur. Swelling of the airway can result in its obstruction and can cause trouble breathing, which is potentially life-threatening. Without treatment, this can cause a risk of death in about 25% of people. With treatment, outcomes are generally good. Without preventive treatment, attacks typically occur every two weeks and last for a few days. There are three main types of HAE. Types I and II are caused by a mutation in the SERPING1 gene, which encodes the C1 inhibitor protein, and type III, now called HAE with normal C1 inhibitor (HAE-nl-C1INH). Types I and II affect females and males equally, while HAE with normal C1 inhibitor affects females more often than males. Six known mutations are described in the literature under HAE with normal C1 inhibitor. The result is increased levels of kallikrein activity and bradykinin, which promotes swelling. The condition may be inherited in an autosomal dominant manner or occur as a spontaneous mutation. Known common HAE triggers are: Stress Minor trauma Anxiety S...