Researchers at the University of Pittsburgh Medical Center (UPMC) in Pittsburgh have announced that they have identified a new gene responsible for a rare, inherited form of sudden cardiac arrest, known as Brugada syndrome.
The researchers hope the identification will shed light on more common forms of sudden death in heart attack and heart failure patients, as well as help in the development of new, effective therapeutic treatments to prevent all types of fatal arrhythmias.
Barry London, MD, lead author of the study, a professor of medicine and chief, division of cardiology at the University of Pittsburgh School of Medicine and director of the UPMC Cardiovascular Institute and colleagues, reported their findings in the November online version of Circulation.
London and colleagues identified a mutation in a previously unstudied gene, GPD1-L, on chromosome 3p24. The mutation impairs the heart's natural electrical ability to beat in a coordinated manner and maintain a stable rhythm. Until their discovery, only ion channel genes had been shown to cause Brugada syndrome.
“In this study we found that GPD1-L, while not an ion channel itself, is a trafficking gene that allows the sodium channel to find its way to the cell membrane. The mutation interferes with the trafficking and leads to potentially fatal arrhythmias,” London said. “Equally important, we suspect that the function of the native GPD1-L gene and the mutant are influenced by oxidative stress, a process which interferes with the body's natural ability to repair itself from antioxidant assaults,” such as pollution, smoking or stress.
London said that patients with Brugada syndrome, only rarely have symptoms but have this genetic mutation all the time. Therefore, “something else is happening concurrently with this mutation to trigger the potentially lethal rhythm problems. With the identification of this new GPD1-L gene, we hope to identify other new genes along with entirely new pathways that stabilize the rhythm of the heart," London said.
"Of note, our collaborators have shown that mutations in GPD1-L also cause other heart rhythm disorders," according to London.