The Michigan Genomics Initiative: a biobank linking genotypes and electronic clinical records in Michigan Medicine patients

Abstract

The recent wave of biobank repositories linking individual-level genetic data with dense clinical health history has introduced a dramatic paradigm shift in phenotyping for human genetic studies. The mechanism by which biobanks recruit participants can vary dramatically according to factors such as geographic catchment and sampling strategy. These enrollment differences leave an imprint on the cohort, defining the demographics and the utility of the biobank for research purposes. Here we introduce the Michigan Genomics Initiative (MGI), a rolling enrollment, single health system biobank currently consisting of >85,000 participants recruited primarily through surgical encounters at Michigan Medicine. A strong ascertainment effect is introduced by focusing recruitment on individuals in Southeast Michigan undergoing surgery. MGI participants are, on average, less healthy than the general population, which produces a biobank enriched for case counts of many disease outcomes, making it well suited for a disease genetics cohort. A comparison to the much larger UK Biobank, which uses population representative sampling, reveals that MGI has higher prevalence for nearly all diagnosis- code-based phenotypes, and larger absolute numbers of cases for many phenotypes. GWAS of these phenotypes replicate many known findings, validating the genetic and clinical data and their proper linkage. Our results illustrate that single health-system biobanks that recruit participants through opportunistic sampling, such as surgical encounters, produce distinct patient profiles that provide an ideal resource for exploring the genetics of complex diseases.