Hosts, Andrew Marderstein and Lucia Hindorff, chat with Bárbara Bitarello on her work, " Polygenic Scores for Height in Admixed Populations" and what led to her career path. Check out the written interview by visiting the ASHG website. Read the paper here: “Polygenic Scores for Height in Admixed Populations” Listen here
Listen here. Polygenic risk scores (PRS) rely on the genome-wide association studies (GWAS) to predict the phenotype based on the genotype. However, the prediction accuracy suffers when GWAS from one population are used to calculate PRS within a different population, which is a problem because the majority of the GWAS are done on cohorts of European ancestry. In this episode, Bárbara Bitarello helps us understand how PRS work and why they don’t transfer well across populations.
Abstract Polygenic risk scores (PRS) summarize the results of GWAS into a single number that can predict quantitative phenotype or disease risk. One barrier to the use of PRS in clinical practice is that the majority of GWAS come from cohorts of European ancestry, and predictive power is lower in non-European ancestry cohorts. There are many possible reasons for this decrease; here we show that differences in allele frequencies, LD patterns, and phenotypic variance across ancestries are unlikely to be driving this pattern.
Abstract | The vast majority of genome-wide association studies (GWAS) are performed in cohorts of European ancestry. Systematic differences in polygenic risk scores (PRS) between European and non-European ancestry populations are believed to be largely spurious. However, it is not clear whether they are completely inaccurate nor how much individual-level predictive power is lost by applying PRS based on European-ancestry GWAS to non-European ancestry populations. Finally, a quantitative understanding of the biological or statistical basis for the poor performance of PRS in non-European-ancestry populations is lacking.