In recognition of American Heart Awareness Month this February and Rare Disease Day on February 28th, this week's blog focuses on a rare cardiovascular disorder known as Brugada syndrome.
Never heard of Brugada syndrome?
Continue reading to find out more about this condition.
Brugada syndrome is an inherited cardiovascular disorder characterized by cardiac conduction abnormalities. It may present during infancy as sudden infant death syndrome (SIDS) or later in adulthood as sudden unexpected nocturnal death syndrome (SUNDS).
Common Features of Brugada Syndrome
- Frequently seen in individuals in their fourth decade of life
- Personal history of recurrent syncope (temporary loss of consciousness and posture aka fainting or passing out)
- Family history of sudden cardiac death
- Malignant arrhythmias (irregular heart beat)
- Cardiac arrest
An implantable cardioverter defibrillator (ICD) is the primary treatment for those who are high risk, (i.e have Brugada syndrome and a personal history of syncopal episodes). The ICD continually monitors the heart's rhythm and provides an electric shock to the heart to restore a normal heartbeat and to prevent cardiac arrest. Medications may be prescribed for individuals who do not fall into the high risk catergory; however, drug therapy may be controversial.
Genetic Testing for Brugada Syndrome
Identification of a pathogenic variant in an individual with Brugada syndrome can assist in family planning and risk assessment for family members. More than 200 pathogenic changes in 15 different genes have been identified in 30-35% of Brugada syndrome cases. Pathogenic variants in other genes including, CACNA1C, CACNB2, GPD1L, HCN4, KCNE3, SCN1B, and SCN3B, have also been identified as causative of Brugada syndrome. Most individuals have an affected parent, but approximately 1% of cases have a de novo pathogenic variant.
If sequential gene testing is preferred, SCN5A is usually the first gene to be analyzed since 15-30% of individuals with Brugada syndrome have a pathogenic variant in this gene. A multi-gene panel for Brugada-related genes may be the best options, however. Before choosing a cardiac panel, it is important to determine if the panel is the most appropriate panel for a suspected diagnosis of Brugada syndrome, because some panels may include genes that are not directly associated with the condition.
If single-gene and panel test results are negative, exome sequencing may also be explored. Exome sequencing has an average diagnostic yield of approximately 30%, but is more likely to return results of unknown significance than single and multi-gene testing.
EGL offers testing for Brugada syndrome and other inherited cardiac disorders. Click the below heart image to learn about this testing.
Support and Advocacy
While Brugada syndrome is labeled as a rare condition, it is possible that it is underdiagnosed. While the exact prevalence is unknown, estimates have varied between 5 in 10,000 to 20 in 10,000 in different populations throughout the world. To help spread awareness about Brugada syndrome and other inherited cardiac conditions, the Sudden Arrhythmia Death Syndromes (SADS) Foundation was created.
The SADS Foundation
The SADS Foundation is an advocacy organization that helps those with sudden arrhythmia syndromes. They have resources such as a phyiscian locater, guides on how to tell relatives about a diagnosis, and information about genetic testing and staying healthy. Click the image above to learn about SADS.
You may also like to read about how twin brothers from University of Kentucky learned about their diagnoses and how it saved their lives, by clicking here.