Genetic Data May Not Boost Heart Disease Predictions
MONDAY Jan. 19, 2009 -- Although a particular genetic variation is associated with an increased risk for heart disease, knowing about it does not help doctors predict who is likely to get heart disease any more than using traditional risk factors, a new study finds.
There has been continuing excitement in recent years about the power of gene variations in predicting the risk for disease. However, in this case, knowing a variation increases the risk of cardiovascular trouble did not add more valuable information than could be gleaned from other risk factors, such as high blood pressure, high cholesterol and family history.
"Gene patterns are associated with an increased risk of heart disease, and the higher risk patterns are common," said lead researcher Nina P. Paynter, an instructor in medicine at Brigham and Women's Hospital in Boston and Harvard Medical School.
"However, it was not known if knowledge of a person's pattern, when added to knowledge of traditional risk factors including family history of heart disease, would improve the ability to predict levels of future heart disease risk for that person and possibly help with treatment decisions," she said.
The report is published in the Jan. 20 issue of the Annals of Internal Medicine.
For the study, Paynter's team collected data on 22,129 women who participated in the Women's Genome Health Study. At the start of the study, the women were free from any major chronic diseases.
Over 10.2 years of follow-up, the researchers found that adding information about gene patterns at a specific section of the genome, namely chromosome 9p21.3, did not meaningfully improve the ability to predict heart disease, compared with the use of traditional risk factors.
"This study only included white women, so it is not known if the results are applicable to women of different backgrounds or to men," Paynter noted.
Dr. Harlan M. Krumholz, a professor of cardiology at Yale University School of Medicine, put it this way: "It's an important study that should give us pause that information about whether our DNA will trump what we know from established risk factors. The genetic work is important in efforts to find targets for future therapies, but addressing modifiable risk factors is where we need to direct our attention."
However, Dr. Byron Lee, an assistant professor of cardiology at the University of California, San Francisco, noted that "while in this study, DNA testing did not improve our ability to predict cardiovascular disease, which is based on traditional risk factors like smoking and hypertension, there are literally millions of other specific genetic tests to look at."
"I expect DNA testing to become a standard part of risk assessment in the near future," Lee said.
For more information on heart disease, visit the American Heart Association .
Posted: January 2009