Researchers from Brigham and Women’s Hospital (BWH) assessed the predictive ability of a comprehensive genetic risk score among more than 19,000 women enrolled in the BWH-based Women’s Genome Health Study.
After more than a decade of follow-up, the researchers found that genetic screening offered very little beyond traditional factors such as age, blood pressure, smoking status and cholesterol. However, they also found that self-reported family history, such as parental history of heart attack before age 60, did provide useful information about risk. The findings appear in the February 17, 2009 issue of the Journal of the American Medical Association.
Mining results from prior genome wide association studies (GWAS) conducted by researchers worldwide that are catalogued by the National Human Genome Research Institute, the BWH researchers developed two genetic risk scores; one based on 12 genetic markers known to be linked to CVD and another including an additional 89 genetic markers linked to traditional risk factors such as blood pressure and cholesterol levels, among others.
The genetic risk scores were then tested among 19,313 initially healthy women from the BWH-based Women’s Genome Health Study (WGHS) who were followed over a 12 year period for the development of heart attacks, stroke, the need for coronary revascularization, or cardiovascular death. The researchers tested the predictive ability of the genetic information alone as well as in combination with known traditional risk factors, and compared the genetic information to self-reported family history of heart attack among the study participants.
Overall, the researchers found that the genetic data marginally predicted risk on its own but had almost no clinical utility once traditional risk factors were also considered. On the other hand, simply knowing whether or not a parent had suffered from a heart attack before age 60 was informative about future risk.
“While genetic testing is becoming more and more available, it may be that for now the most useful way to learn about your genetic risk for cardiovascular disease is still to talk to your parents,” said Nina Paynter, PhD, researcher in the Center for Cardiovascular Disease Prevention at BWH. “Family history brings together not only shared genetics, but also shared behaviors and environmental factors.”
Dr. Paul Ridker, director of the Center for Cardiovascular Disease Prevention at BWH and principal investigator of the WGHS added, “Understanding genetics and its role in chronic disease remains absolutely vital for developing new therapies and new approaches to treatment. Our data in no way undermine those efforts. However, it is sobering to find that the current body of genetic data adds little to our ability to predict cardiovascular disease”.
The Women’s Genome Health Study (WGHS) derives from the Women’s Health Study (WHS), both of which receive funding from the National Heart Lung and Blood Institute, the National Cancer Institute, the Donald W. Reynolds Foundation, and the Leduq Foundation. Genotyping for the WGHS was supported by Amgen, Inc. Other BWH investigators involved in the project include Drs. Daniel Chasman, Julie Buring, and Nancy Cook.