Overview of challenges and opportunities of GWAS as it relates to epidemiology and public health

This presentation will provide a brief overview of the Genome-wide Association Study (GWAS) design including the opportunities and challenges associated with this popular method. GWAS that assay extremely large panels of single nucleotide variants (SNPs) in thousands of individuals provide promise for the identification of genes associated with common, complex diseases. In the past five years, GWAS have detected many robust associations between these genetic variants and various diseases and continuous traits. From these collective studies we have learned that oftentimes the effect sizes of the SNP-trait/disease association are small (Odds Ratios < 1.5), risk variants can lie in genomic regions not previously indicated in a particular disease or trait, and some risk loci appear to be commonly associated with more than one disease not previously thought to share the same underlying etiology. Data gleaned from the National Human Genome Research Institute (NHGRI) GWAS catalogue (http://www.genome.gov/gwastudies/) will be presented along with a brief introduction of various tools including the National Center for Biotechnology Information (NCBI) Database of Genotypes and Phenotypes (dbGaP; www.ncbi.nlm.nih.gov/gap).