PT - JOURNAL ARTICLE AU - Minsun Song AU - Wei Hao AU - John D. Storey TI - Testing for genetic associations in arbitrarily structured populations AID - 10.1101/012682 DP - 2014 Jan 01 TA - bioRxiv PG - 012682 4099 - http://biorxiv.org/content/early/2014/12/12/012682.short 4100 - http://biorxiv.org/content/early/2014/12/12/012682.full AB - We present a new statistical test of association between a trait (either quantitative or binary) and genetic markers, which we theoretically and practically prove to be robust to arbitrarily complex population structure. The statistical test involves a set of parameters that can be directly estimated from large-scale genotyping data, such as that measured in genome-wide associations studies (GWAS). We also derive a new set of methodologies, called a genotype-conditional association test (GCAT), shown to provide accurate association tests in populations with complex structures, manifested in both the genetic and environmental contributions to the trait. We demonstrate the proposed method on a large simulation study and on the Northern Finland Birth Cohort study. In the Finland study, we identify several new significant loci that other methods do not detect. Our proposed framework provides a substantially different approach to the problem from existing methods. We provide some discussion on its similarities and differences with the linear mixed model and principal component approaches.