New Therapies for Type 1 and Type 2 Hereditary Angioedema

Hereditary angioedema is a rare disorder characterized by recurrent episodes of mucosal swelling. The disease is usually caused by autosomal dominant mutations in SERPING1, which encodes C1 inhibitor. Type 1 hereditary angioedema is caused by deficiency of C1 inhibitor, whereas type 2 hereditary angioedema is due to dysfunction of C1 inhibitor. As shown in Figure 1, the absence or dysfunction of C1 inhibitor leads to elevated levels of bradykinin, which acts through bradykinin B2 receptors and triggers increased vascular permeability, resulting in angioedema. Episodes of angioedema can be precipitated by surgery, accidental trauma, stress, and menstruation. The most feared complication . . .