The most common gene for a syndrome associated with abnormal heart rhythms and sudden death triggers epileptic seizures and could explain sudden unexplained death in epilepsy, said researchers from Baylor College of Medicine in a recent report.
The identification of this particular potassium channel KvLQT in neurons of the central nervous system gives scientists a clue about which epilepsy patients face the greatest risk of dying unexpectedly, said Dr. Jeffrey Noebels, the study’s senior author and director of the Blue Bird Circle Developmental Neurogenetics Laboratory at BCM. The channel has been identified in heart muscle cells and now for the first time in brain or nerve cells.
“Idiopathic (unexplained) epilepsy is one of neurology’s oldest mysteries. While most persons with epilepsy will have a normal lifespan, our finding now points the way to a simple and essential test to identify risk for sudden death in persons with seizures of unknown origin. In these patients, a routine cardiology evaluation consisting of an EKG,and if indicated, a genetic screening test for this family of genes can positively identify this new risk factor,” said Noebels. “If the gene test is positive, there are effective treatments for the heart irregularity, including drugs known as beta blockers, as well as the use of a cardiac pacemaker to prevent lethal arrhythmias.”
As many as 18 percent of deaths in epilepsy come suddenly without warning, devastating families.
Others who took part in this work include Ed Glasscock, Jong Yoo, Tara Klassen and Tim Chen. Funding for the work came from the Dana Foundation, the National Institutes of Health, the American Heart Association, and Blue Bird Circle Foundation of Houston.