Researchers from Brigham and Women’s Hospital, Veterans Affairs (VA) Boston Healthcare System, and Harvard Medical School today release polygenic risk scores (PRS) for six common disease as part of the Genomic Medicine at VA (GenoVA) Study. As part of the study, published today in Nature Medicine, the investigators have developed informational resources for each disease to help physicians and patients learn how to incorporate PRS for medical decisions about screening and prevention.
“As a primary care physician myself, I knew that busy physicians were not going to have time to take an entire course on polygenic risk scores,” said corresponding author Jason Vassy, MD, of the Brigham’s Division of General Internal Medicine & Primary Care, the Brigham’s Precision Population Health at Ariadne Labs and VA Boston. “Instead, we wanted to design a lab report and informational resources that succinctly told the doctor and patient what they need to know to make a decision about using a polygenic risk score result in their health care.”
The GenoVA Study is continuing to enroll patients fom the VA Boston Healthcare System. The reported findings are from the study’s first 227 patients. From this group, the researchers found that 11% have a high polygenic risk score for atrial fibrillation, 7% for coronary artery disease, 8% for type 2 diabetes, and 6% for colorectal cancer. Of the men enrolled in the study, 15% had a high score for prostate cancer, while 13% of the women enrolled had a high score for breast cancer.
While the researchers had to overcome a number of challenges in developing and implementing a clinical lab test for PRS, their early work has also confirmed a problem previously acknowledge about the shortcomings of PRS, namely that they are less accurate in individuals of non-European descent. This is because most genomic research to date has been conducted in European populations, leading to less accurate PRS scores of disease risk among non-European populations.
To address this problem, and to ensure that the use of PRS is more broadly applicable, without adding to existing healthcare disparities, the researchers applied additional statistical methods to enable PRS calculation across multiple racial groups.
“Researchers must continue working to increase the diversity of patients participating in genomics research,” said Matthew Lebo, PhD, hief Laboratory Director at the Mass General Brigham Laboratory for Molecular Medicine (LMM). “In the meantime, we were heartened to see that we could generate and implement valid genetic scores for patients of diverse backgrounds.”
But it is also important to develop more data directly from diverse populations in order to democratize the application of PRS in the clinical setting. The GenoVA study is also addressing this, as 52% of the study enrollees report non-white race and/or Hispanic/Latinx ethnicity.
Another challenge in bringing polygenic risk score to clinical medicine is helping physicians and patients understand the scores and how to use them to make medical and preventive health decisions. Clinical guidelines do not yet exist to help a physician know whether and how they should treat a patient with a high-risk score differently than an average-risk patient, but the study provides physician- and patient-oriented educational materials to help them incorporate the results.
The GenoVA Study will ultimately enroll more than 1,000 patients and follow them for two years to observe how they and their primary care providers use the polygenic risk scores in clinical care and how these decision affect disease prevention and outcomes.
