Overview of the eMERGE PRS process. Participant DNA is genotyped using the Illumina Global Diversity Array, which assesses 1.8 million sites. Genotyping data are phased and imputed with a reference panel derived from the 1,000 Genomes Project. For each participant, raw PRSs are calculated for each condition ( PRS raw ). Each participant’s genetic ancestry is algorithmically determined in the projection step. For each condition, an ancestry calibration model is applied to each participant’s z- scores based on model parameters derived from the All of Us Research Program (Calibration) and an adjusted z -score is calculated ( PRS adjusted ). Participants whose adjusted scores cross the predefined threshold for high PRS are identified and a pdf report is generated. The report is electronically signed after data review by a clinical laboratory director and delivered to the study portal for return to the clinical sites.
