Definition
Hereditary Angioedema (HAE) is a rare genetic disease that causes recurrent episodes of swelling (edema), which can be severe.
It was first described in 1882 by the German physician Heinrich Quincke. In 1888, the physician William Osler identified its hereditary pattern by observing several cases of the disease within the same family.
Unlike common allergies, HAE can affect people of any sex, age or background, and its symptoms do not improve with usual allergy treatments such as antihistamines and corticosteroids.
Prevalence
HAE is considered a rare disease, affecting approximately 1 in every 30,000 to 50,000 people.
Many cases remain undiagnosed. Due to limited awareness of the disease, it is common for patients to wait years before receiving an accurate diagnosis.
Current HAE classification
Currently, Hereditary Angioedema (HAE) is classified into two major groups, according to its genetic and laboratory basis:
1) HAE with C1-Inhibitor deficiency
This is the most common group. It occurs due to mutations in the SERPING1 gene, which lead to decreased levels or malfunction of the C1-INH protein.
Without proper C1-INH function, there is excessive production of bradykinin , a substance responsible for increased vascular permeability and swelling.
Type I
Reduced levels of C1-INH (most common form).
Type II
Normal levels, but with inadequate C1-INH function.
2) HAE with normal C1-Inhibitor
In this group, the levels and function of C1-INH are normal, but other genetic mutations are involved.
Identified mutations include:
Important: there are still cases in which no known mutation is identified, and scientific research continues to evolve.