title: Uncovering the Genetic Architectures of Quantitative Traits.
abstract: The aim of a genome-wide association study (GWAS) is to identify loci in the human genome affecting a phenotype of interest. This review summarizes some recent work on conceptual and methodological aspects of GWAS. The average effect of gene substitution at a given causal site in the genome is the key estimand in GWAS, and we argue for its fundamental importance. Implicit in the definition of average effect is a linear model relating genotype to phenotype. The fraction of the phenotypic variance ascribable to polymorphic sites with nonzero average effects in this linear model is called the heritability, and we describe methods for estimating this quantity from GWAS data. Finally, we show that the theory of compressed sensing can be used to provide a sharp estimate of the sample size required to identify essentially all sites contributing to the heritability of a given phenotype.
authors.affiliation: Department of Psychology, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Mathematical Biology Section, NIDDK/LBM, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Shashaank
authors.initials: S
authors.lastname: Vattikuti
authors.affiliation: Mathematical Biology Section, NIDDK/LBM, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Carson C
authors.initials: CC
authors.lastname: Chow
keywords: Average effect of gene substitution; Compressed sensing; GWAS; Heritability; Population genetics; Quantitative genetics; Review; Statistical genetics