What Is HAE?

Hereditary angioedema (HAE) is a rare disease that can typically cause attacks of swelling in the stomach (abdomen), face, feet, genitals, hands, and throat

It is estimated that HAE affects only 1 in 50,000 people.

Most people with HAE either don’t have enough C1-INH protein or it does not work properly, causing overactivation of plasma kallikrein. This triggers the uncontrolled release of bradykinin, causing blood vessels to release fluid and resulting in the localized swelling and pain of an HAE attack.

Types of HAE

There are two main types of HAE, called type 1 and type 2.

  • Type 1 is the most common form. People with type 1 do not make enough of the protein C1-INH, so circulating levels in the blood are too low.
  • People with HAE type 2 have normal, or even higher, levels of C1-INH, but this protein does not work as it should.