Genetic Association Testing with Quantitative Traits in Samples with Pedigree and Population Structure

• Activity Number: 164
• Type: Topic Contributed
• Date/Time: Monday, July 30, 2012 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Timothy Thornton*+
• Companies: University of Washington
• Keywords: GWAS ; Population Structure ; Quantitative Traits ; Pedigrees ; Association ; Relatedness

Abstract

Genome-wide association studies (GWAS) are commonly used for the mapping of genetic loci that influence complex traits. The observations in GWAS can have several sources of dependence, including population structure and relatedness among the sample individuals, some of which might be know and some unknown. It is well known that failure to appropriately account for both pedigree and population structure can lead to spurious association and reduced power. We propose a novel method for association testing of quantitative traits in samples with partially or completely unknown population and pedigree structure. Features of the method include: (1) it is applicable and computationally feasible for a variety of study designs, ranging from studies that have a combination of unrelated individuals and small pedigrees, to studies of isolated founder populations; (2) it can incorporate phenotype information on relatives with missing genotype data; and (3) it is completely applicable to arbitrary phenotypes. We demonstrate the power and validity of the proposed method in simulation studies with related individuals and population structure, including admixture.