BALTIMORE, May 1 (UPI) -- Researchers said Monday they have found a gene that is linked to abnormal heartbeat, a primary culprit in sudden cardiac death.
Using new genomic technology to pinpoint common genetic variants that contribute to diseases, researchers at Johns Hopkins have identified a gene that may predispose some people to abnormal heart rhythms, a condition that affects more than 300,000 people in the United States each year.
The suspect gene is NOS1AP -- which was not previously linked to abnormal heart rhythms via previous gene-finding methods -- and it appears to have a significant impact on the heart's QT interval length, or the time between heartbeats.
"There's a great deal of evidence out there that having a too long or too short QT interval is a risk factor for sudden cardiac death," said the study's co-first author, Dan Arking, an instructor in Johns Hopkins McKusick-Nathans Institute for Genetic Medicine. "This makes it appealing to study because it can be measured non-invasively with an EKG, and each person's QT interval, in the absence of a major cardiovascular event, is stable over time, making it a reliable measure," he said.
Researchers believe that a variety of factors, both genetic and environmental, contribute to irregular heartbeat and other conditions that may lead to sudden cardiac death.
"Being able to identify predisposed individuals can save their lives by prescribing beta-blockers and other drugs that regulate heart rhythm, and even by implanting automatic defibrillators in those with the highest risk," the Johns Hopkins team said.
The researchers said they used an unconventional approach to find the gene by ignoring the usual candidate genes already highly suspect in influencing heartbeat rhythm and instead focusing on people who have extremely long or short QT intervals.
They looked at subjects from two population-based studies, about 1,800 U.S. adults of European ancestry from the Framingham Heart Study of Framingham, Mass., and about 6,700 German adults from the KORA-gen study of Augsburg, Germany.
The researchers then looked for any specific DNA sequences that showed up more frequently in people who have longer or shorter QT intervals than in those with normal QT intervals. To do this, they examined the DNA sequences of both long and short QT people.
The study findings were published April 30 in the online edition of Nature Genetics.
