Newly Developed Polygenic Risk Scores May Assist Decision-making in Primary Care

Researchers have developed polygenic risk scores (PRS) for 6 common diseases as well as informational resources to help primary care physicians incorporate them into clinical practice.

Findings validating the PRS were published online ahead of print April 18, 2022, in Nature Medicine by a group of investigators from Brigham and Women’s Hospital, Veterans Affairs Boston Healthcare System, and Harvard Medical School.

“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, MPH, associate professor of medicine, Brigham and Women’s Hospital, in a press release. “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.”

Vassy and colleagues developed the PRS as part of the ongoing Veterans Affairs Genomic Medicine at Veterans Affairs (GenoVA) Study. The team used data from 36 423 participants in the Mass General Brigham Biobank and adjusted for population structure to replicate known PRS-disease associations and published PRS thresholds for 6 target diseases: atrial fibrillation (AF), breast cancer, colorectal cancer, coronary artery disease (CAD), prostate cancer, and type 2 diabetes mellitus (T2D).

After validating the PRS, researchers then used them to analyze samples from the first 227 patients enrolled in the GenoVA Study. Patients eligible for GenoVA have no history of the target diseases and range in age from 50 to 70 years—a range during which “much guideline-recommended screening and diagnosis of new disease occurs,” wrote authors.

Overall, 11% of patients were found to have a high PRS for AF, 7% for CAD, 8% for T2D, and 6% for colorectal cancer. Among men, 15% had a high PRS for prostate cancer and 13% of women had a high score for breast cancer, according to the study results.

Vassy et al observed racial disparities in the distribution of each PRS, most notably in AF, CAD, and T2D. For example, Asian participants had no associated risk for colorectal cancer (odds ratio [OR]=0), while risk was present for Black (OR=4.11; 95% CI, 1.17-14.48) and White patients (OR=2.29; 95% CI, 1.65-3.19).

In addition to the PRS laboratory report, the team developed and distributed physician- and patient-oriented informational materials to support decision-making about PRS results.

“Our work illustrates the generalizable development of a clinical PRS assay for multiple conditions and the technical, reporting and clinical workflow challenges for implementing PRS information in the clinic,” concluded authors.