Gretchen Saunders on the Cross-Population Transferability of Polygenic Scores

In the world of behavior genetics, polygenic scores are markers that can provide critical information about a person’s health risk for a particular disease or other condition as compared to others with different genetic makeups. University of Minnesota Psychology researchers Gretchen Saunders, staff, and Scott Vrieze, faculty, conducted a study, “Insights into the Cross-Population Transferability of Polygenic Scores for Substance Use,” evaluating the extent to which substance use-related polygenic scores are transferable across populations worldwide, thereby expanding their potential use.

Polygenic scores offer potential as predictors of health outcomes in relation to substance use, but prior research has been primarily conducted in individuals of European genetic ancestry. Saunders and Vrieze sought to address this by examining this prediction in European, African, American, and East Asian populations. The pair found that when applied to non-European populations, the predictive accuracy of the European-based polygenic risk scores drastically decreased. In evaluating the causes of this poor transferability, they attribute this decline to the fact that populations differ in how common specific genetic variants are, how nearby genes are inherited together, and how strongly genetics influences substance use behavior within each population. In sum, this study highlights the importance of incorporating genetic diversity in current and future research to improve the broad applicability of polygenic scores.