Polygenic Risk Score (PRS) Builder Build and interpret polygenic risk scores for complex diseases using genome-wide association study (GWAS) data. Reasoning Strategy A polygenic risk score predicts genetic risk, not disease. A high PRS means elevated risk relative to the population — it does not mean the person will develop the condition, and a low PRS does not confer immunity. PRS performance varies dramatically across ancestries: a European-derived PRS applied to a West African population can lose 50–70% of its predictive power because the underlying GWAS was trained on European allele freq…