Polygenic risk scores may assist decision-making in primary care
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Researchers said they have developed polygenic risk scores for six common diseases that may offer clinically meaningful information about a person’s disease risk.
Findings validating the risk scores were recently published in Nature Medicine.
“Polygenic risk scores might allow more precise risk prediction for an individual, which could enable more targeted prevention,” Jason Vassy, MD, MPH, a clinician-investigator in the division of general internal medicine and primary care at Brigham and Women’s Hospital and in the VA Boston Healthcare System, told Healio.
Vassy and colleagues used data from 36,423 participants enrolled in the Mass General Brigham Biobank and adjusted for population structure to replicate known polygenic risk score disease associations for atrial fibrillation, breast cancer, colorectal cancer, coronary artery disease, prostate cancer and type 2 diabetes.
“We took polygenic risk scores from the published literature and used those publications to identify, for each disease, the [polygenic risk score] cut point corresponding to an odds ratio greater than or equal to 2 (ie, at least double the odds of developing the disease),” Vassy told Healio. “To make sure we could replicate those associations ourselves, we looked at the odds of disease for people below and above those cut points in the Mass General Brigham Biobank. We wanted to make sure those ORs were also close to 2, to show that we had replicated the published findings. We were pleased to see that we generally replicated the published results.”
After validating the risks scores, the researchers then used them to assess prospective samples from 227 patients in the GenoVA Study, a randomized clinical trial of polygenic risk score testing of healthy adults. Among the patients, 52% identified with a race other than white.
Overall, 11% had a high polygenic risk score for atrial fibrillation, 7% for coronary artery disease, 8% for type 2 diabetes and 6% for colorectal cancer. Vassy and colleagues also reported that 15% of men had a high score for prostate cancer and 13% of women had a high score for breast cancer.
The researchers found that the polygenic risk scores were less accurate in predicting disease risk in patients of non-European descent, Vassy said. To reduce health disparities, Vassy and colleagues calculated more specific risk scores by racial group. These calculations revealed variability in prevalence and risk scores. For example, Asian patients had no associated risk for colorectal cancer (OR = 0), while risk was present for Black patients (OR = 4.11; 95% CI, 1.17-14.48) and white patients (OR = 2.29; 95% CI, 1.65-3.19).
The GenoVA Study will enroll more than 1,000 additional patients. The researchers will follow participants for 2 years to observe how they and their primary care providers use the polygenic risk scores in clinical practice.
To support decision-making, Vassy and colleagues distributed laboratory reports and educational materials to patients and physicians involved with the GenoVA Study. Patients were also contacted by a genetic counselor to discuss their results.
“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,” Vassy said 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.”
Currently, there are some types of polygenic risk score tests, like for breast cancer, available to patients from direct-to-consumer genetic testing companies, according to Vassy. He said that physicians should encourage patients to share these results to help them make informed decisions.
“It is probably most helpful to think of polygenic risk scores as a risk factor for disease, not a diagnostic test or an indication that an individual will certainly develop the disease,” Vassy said. “Most diseases have complex, multifactorial etiologies, and a high polygenic risk score is just one piece of the puzzle.”
References:
Hoa L, et al. Nat Med. 2022;doi:10.1038/s41591-022-01767-6.
Researchers develop and validate polygenic risk scores for six common diseases. https://www.news-medical.net/news/20220418/Researchers-develop-and-validate-polygenic-risk-scores-for-six-common-diseases.aspx. Published April 18, 2022. Accessed April 18, 2022.