According to a story from Angioedema News, the results of a recent study have led authors to conclude that genetic testing can be useful for the diagnosis of hereditary angioedema without a known cause. This was the result of a case of a female patient who had previously been misdiagnosed, but, following a test, was found to have a previously unconfirmed genetic variant that caused her to experience symptoms of hereditary angioedema.
About Hereditary Angioedema (HAE)
Hereditary angioedema is a genetic disorder which is characterized by chronic episodes of swelling that can affect multiple areas of the body. The condition is caused by mutations affecting the several different genes, depending on the type. Swelling attacks generally occur every two weeks or so; they can usually last for several days. Swelling may affect the limbs, digestive tract, face, and airway, with blockage of the airway being the most dangerous complication. Vomiting and abdominal pain may accompany attack as well if the digestive tract is involved. Treatment involves reducing the likelihood for attacks to appear and preventing them from worsening when they do. Hereditary angioedema is typically only life-threatening if left untreated. Prevalence of the condition is estimated to be around one in 10,000 to one in 50,000, at least in the US and Canada. To learn more about hereditary angioedema, click here.
Disease Variants
Hereditary angioedema has been divided into three standard types; the first two are linked to mutations of the SERPING1 gene while type 3 is caused by a mutation of the F12 gene. However, there are records of patients with the condition that do not have these mutations. In these cases, prior studies have suggested that the K330E variant of the PLG gene and the A119S variant of the ANGPT1 gene.
In the case study, the patient experienced swelling of the tongue and lips by her 21st year. These symptoms manifested on an annual basis and allergy medications had no effect. Genetic testing revealed that the woman carried the K330E variant. Her family had no history of hereditary angioedema.
The authors recommend genetic testing for patients who have unexplained swelling that doesn’t resolve with allergy treatments as it could help identify more patients with these less well known forms of the condition.
Check out the original study here.
