Figure 1.
Top-down and bottom-up approaches to genome-wide association studies. (A) In the top-down approach, clinical investigators assemble cases and controls based on a particular phenotype. Genotypic information is then acquired and deposited in dbGaP. (B) In the bottom-up approach, basic investigators identify in vitro phenotypes based on SNP data in dbSNP. They then access clinical populations and controls with whom they are able to conduct “targeted phenotyping.”
