Which genetic disorder is characterized by decreased C1 esterase inhibitors?

Hereditary angioedema is a genetic disorder caused by a deficiency or dysfunction of C1 esterase inhibitor, a protein that plays a crucial role in regulating vascular permeability and the complement and contact activation pathways. This deficiency leads to uncontrolled activation of these pathways, resulting in episodes of severe swelling (angioedema) in various parts of the body, including the face, extremities, gastrointestinal tract, and respiratory system.

Patients with hereditary angioedema often experience recurrent attacks of swelling without urticaria, and the angioedema can be life-threatening if it occurs in the airway. The attacks can be triggered by physical trauma, stress, infections, or hormonal changes, but they can also occur spontaneously.

This disorder is distinct from the other options listed. For example, Hodgkin's lymphoma is a type of cancer that affects the lymphatic system, while hemophilia is a bleeding disorder caused by a deficiency of clotting factors, and von Willebrand disease is a bleeding disorder resulting from a deficiency in von Willebrand factor, which is involved in platelet adhesion. None of these conditions involve the dysfunction of C1 esterase inhibitor, making hereditary angioedema the correct answer for its direct association with decreased levels of this important