Genetic Testing for Aortic Aneurysms Could Spur Early Treatment and Save Lives

Researchers find genetic clue to identify those at risk for aortic aneurysms.

ByABC News
September 13, 2011, 3:24 PM

Sept. 14, 2011— -- Professional singer and mother of four Patty Peterson led a busy life in 2007, unaware that a rare cardiac condition had turned her heart into a ticking time bomb. It wasn't until that bomb exploded one February evening that she even knew she had an aortic aneurysm -- a swelling in the blood vessel that pumps blood throughout the body.

"I was driving home at about 10:30 at night and I felt something burst in my chest, it felt like a dagger," Peterson told ABC News.

Peterson's aorta had split under the pressure of the swelling, opening a tear in her blood vessel that ran from her heart down to her groin, and is at risk of rupturing at any time. Peterson was rushed to nearby Abbot Northwestern Hospital in Minneapolis, where ER docs had her in open heart surgery within two hours -- quick work that undoubtedly saved her life, she says.

Like most patients with aortic aneurysms, Peterson had had no symptoms until the aneurysm burst. Though aortic aneurysms are highly treatable if found early, it is extremely difficult to predict who's at risk for one.

But new research from the University of Texas Health Sciences Center at Houston points to a way to genetically screen for those at risk of certain types of aortic aneurysms.

Twenty percent of the time, thoracic aortic aneurysms (the more common of the two types, thoracic and abdominal) occur in patients who already have a family history of the disease. At this point, doctors can screen them for certain genes that may indicate they are at increased risk,, but up until recently there was little known about how to screen the other 80 percent of patients who, until their aneurysm ruptures, have no signs, symptoms or family history to alert doctors to their condition.

"We could screen the general population with echocardiograms, but that would be very expensive, so our other option is to screen genetically," says Dr. Dianna Milewicz, senior author on the research, published Sunday in the journal Nature Genetics.

Using the DNA of 765 aortic aneurysm patients who don't have a family history, researchers could identify a gene variant on chromosome 15 that makes its carriers twice as likely to have a thoracic aortic aneurysm and dissection, or TAAD.

Because about 35 percent of the population has this gene variant, this discovery alone is not enough to start genetically screening people for TAAD, but over the next five to 10 years, Milewicz says she and her collaborators at UTHealth and Baylor College of Medicine hope to identify enough gene variants to narrow the focus of the screening.

Silent and Deadly: Aortic Aneurysms and Dissection

What do Richard Holbrooke, John Ritter, Lucille Ball, and King George II of England have in common? They all died from sudden aortic dissection.

One to 2 percent of the population dies each year from aortic aneurysms, mostly individuals over the age of 60. Forty percent of those with aortic aneurysms will die suddenly when they rupture.

"Patients are often undiagnosed until they have a catastrophic event," says Dr. Michael Jaff, medical director of Massachusetts General Hospital's Vascular Center.

If the aneurysm is identified before it ruptures, however, medications to lower blood pressure and lifestyle changes to reduce the chance of straining the aorta can greatly reduce the risk of a rupture. For those lucky to survive a rupture, like Peterson, these treatments become a way of life to reduce the risk of further tears in the aorta.

Because early diagnosis is so crucial in treating TAAD, Jaff says that these findings are "very important."

"This study suggests that we should be more aggressive about pursuing genetic testing," he says.