What is Brugada Syndrome?
It is a potentially life-threatening heart rhythm disorder that can be inherited. A condition that was identified relatively recently, Brugada Syndrome was first described in a series of patients with sudden death who had similar, peculiar electrocardiogram (ECG) abnormalities. It was later found that many of these patients had abnormal function of their sodium ion channels. Patients with Brugada Syndrome develop ventricular tachycardia, a condition where the heart beats too quickly to maintain normal blood flow.
Brugada Syndrome is rare – only approximately four out of 1000 people in the United States have ECG findings that show Brugada Syndrome. It has been found more commonly in men, and in those of Asian descent, and is thought to be the most common cause of sudden death in people less than 50 years. The average age at diagnosis is 42, but it can be presented at any age.
What causes Brugada Syndrome?
Mutations in the sodium ion channel SCN5A, or in genes that regulate the activity of the ion channel, have found to be the cause of Brugada Syndrome. These mutations are autosomal dominant, so only one copy of the mutation is necessary to cause the disease.
However, only 15 to 30 percent of the mutations that cause Brugada Syndrome are identified in genetic tests, so a “negative” genetic test result does not exclude the disease. There are also patients with genetic mutations in SCN5A who never develop the disease – this means that without ECG findings and symptoms, a “positive” test result does not mean a person will develop the disease
Why test for Brugada Syndrome?
Genetic testing for Brugada Syndrome is most useful when a member of a family has been clinically diagnosed with the condition. If the mutation causing the disease in that person is identified, family members can be tested for the disease with genetic screening.
How does the test work?
The genetic test for Brugada Syndrome is a blood test ordered by your physician. Your DNA is extracted from the blood and analyzed by searching for mutations that are associated with the condition. The test takes approximately eight weeks to complete, and the results will be sent to your physician, who will explain the test results to you.
We will need two tubes of blood (about 7 to 10ml) and a signed consent form from you to send to the laboratory. We recommend genetic counselling before genetic tests are ordered to discuss the implications of the testing and potential results.