New genetic clues to identify aneurysm risk in stomach vessel
By American Heart Association News
Fourteen new genes have been linked to an increased risk of an often-deadly condition called abdominal aortic aneurysm, according to a new study in U.S. veterans.
Only about 20% of people survive a rupture of an abdominal aortic aneurysm, a bulging or weakening of the large oxygen-supplying blood vessel that goes from the heart to the abdomen.
Previous studies have detected 10 locations in the human genome associated with potential risks. But this new work, published Monday in the American Heart Association's journal Circulation, more than doubled that number, to a total of 24 genetic factors associated with abdominal aortic aneurysm.
"This new information can enhance screening protocols and help identify individuals at risk for abdominal aortic aneurysm," one of the study's authors, Philip S. Tsao, said in a news release. He is a professor of cardiovascular medicine at Stanford University School of Medicine and director of the VA Palo Alto Epidemiology Research and Information Center for Genomics in California.
The study used the world's largest genetic biobank, the Million Veteran Program, which was created in 2011 to study how genes affect the health of U.S. military veterans. Researchers tested about 18 million DNA sequence variants among more than 7,500 abdominal aortic aneurysm cases and 172,000 veterans who did not have the condition.
The work factored in the effects of blood pressure, finding that a genetic predisposition for an increase of 10 mmHg in diastolic blood pressure – the bottom number in a reading – increased the risk. "We were surprised that diastolic blood pressure, as opposed to systolic blood pressure (the top number), is likely of greater significance in the development of abdominal aortic aneurysm," Tsao said.
The data also showed that 19 of the 24 genetic risk variants for the condition pointed to an increased risk for aneurysms in other parts of the body.
Researchers created a "polygenic risk score" that helped identify groups of people more likely to develop abdominal aortic aneurysms, regardless of known risk factors such as smoking and family history.
The authors said the report is limited because the database primarily includes veterans of European ancestry. They suggest, as genetic technology advances, that research include more samples from people with diverse backgrounds to limit the chance of ethnic disparities in precision medicine.
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