US Hereditary Angioedema Association

Did you know that:

Hereditary Angioedema (HAE) is a very rare and potentially life-threatening genetic condition that occurs in about 1 in 10,000 to 1 in 50,000 people.
HAE symptoms include edema (swelling) in various parts of the body, including: hands, feet, face and airway (throat).
Patients often suffer excruciating abdominal pain, nausea, and vomiting caused by swelling in the intestinal wall.
Swelling of the airway or throat is particularly dangerous, because it can cause death by choking.
HAE is hereditary.
Children have a 50% chance of inheriting HAE if one of the parents has the disease.
The absence of a family history does not rule out the diagnosis of HAE, as scientific reports indicate that as many as 25% of HAE cases result from a spontaneous mutation of the C1-inhibitor gene at conception. Children of these patients may also inherit HAE.
HAE patients have a defect in the gene that controls a blood protein called C1 Inhibitor. This defect causes a biochemical imbalance that produces swelling. HAE is also known as C1 Inhibitor Deficiency- Type I and Type II.
Patients with a third type of Hereditary Angioedema, called HAE with Normal C1 Inhibitor, experience similar symptoms as Type I and II HAE patients, but have adequate levels of C1 Inhibitor in their blood.

Comprehensive Table of Angioedema Types
Get the full overview of HAE types in our Comprehensive Table of Angioedema Types.

download the table here (pdf).

HAE Disease
Why is Diagnosis Important?

FDA approved treatments for HAE have been available in the US since late 2008.
It is common for HAE patients to remain undiagnosed for many years.
Frequent and severe abdominal pain has historically been inappropriately diagnosed.
Unnecessary exploratory surgery has historically been performed on HAE patients experiencing painful abdominal attacks.
Before therapy became available, the mortality rate caused by throat swelling was reported as high as 30%.

Examples of swelling: