Thus, our study took place in three “phases” that differed with respect to samples and genotyping. “Phase 1” designates our own GWAS sample. “Phase 2” designates the addition of SNP data from SAGE (which used a very different recruitment strategy, but similarly ascertained subjects, and was genotyped on a different microarray) combined with our sample by meta-analysis; this is the core of the GWAS discovery and replication strategy. “Phase 3” designates our own smaller replication sample, where individual SNPs rather than GWAS arrays were genotyped. With these strategies, we identified genetic variants that increase risk for OD and related heritable traits.
