Question: How many people are affected by hereditary angioedema ?
Answer: Hereditary angioedema is estimated to affect 1 in 50,000 people. Type I is the most common, accounting for 85 percent of cases. Type II occurs in 15 percent of cases, and type III is very rare.
Source: GHR

Question: What are the genetic changes related to hereditary angioedema ?
Answer: Mutations in the SERPING1 gene cause hereditary angioedema type I and type II. The SERPING1 gene provides instructions for making the C1 inhibitor protein, which is important for controlling inflammation. C1 inhibitor blocks the activity of certain proteins that promote inflammation. Mutations that cause hereditary angioedema type I lead to reduced levels of C1 inhibitor in the blood, while mutations that cause type II result in the production of a C1 inhibitor that functions abnormally. Without the proper levels of functional C1 inhibitor, excessive amounts of a protein fragment (peptide) called bradykinin are generated. Bradykinin promotes inflammation by increasing the leakage of fluid through the walls of blood vessels into body tissues. Excessive accumulation of fluids in body tissues causes the episodes of swelling seen in individuals with hereditary angioedema type I and type II. Mutations in the F12 gene are associated with some cases of hereditary angioedema type III. This gene provides instructions for making a protein called coagulation factor XII. In addition to playing a critical role in blood clotting (coagulation), factor XII is also an important stimulator of inflammation and is involved in the production of bradykinin. Certain mutations in the F12 gene result in the production of factor XII with increased activity. As a result, more bradykinin is generated and blood vessel walls become more leaky, which leads to episodes of swelling in people with hereditary angioedema type III. The cause of other cases of hereditary angioedema type III remains unknown. Mutations in one or more as-yet unidentified genes may be responsible for the disorder in these cases.
Source: GHR

Question: What are the treatments for hereditary angioedema ?
Answer: These resources address the diagnosis or management of hereditary angioedema: - Genetic Testing Registry: Hereditary C1 esterase inhibitor deficiency - dysfunctional factor - Genetic Testing Registry: Hereditary angioneurotic edema - Genetic Testing Registry: Hereditary angioneurotic edema with normal C1 esterase inhibitor activity - MedlinePlus Encyclopedia: Hereditary angioedema These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Source: GHR