Three hundred and fifty one variants with suggestive P-values < 1.0 × 10−5 in the discovery sample (149 for CD, and 202 for OD) were tested in the replication samples. Several of these did not yield a valid result due to low MAF or imputation quality in their respective ancestry group or substance. Valid results were obtained for 142 CD SNPs and 200 OD SNPs in COGA and 170 OD SNPs in CATS. After correcting for the number of tests performed, none of the GWS hits in the discovery met criteria for replication. Several variants were at or near nominal significance with the same effect direction as Yale-Penn in COGA/CATS and improved the association signal after meta-analysis. The strongest signal in any of the replication samples was in the OD analysis with rs8063946 (P = 3.70 × 10−4 in COGA AAs) in the gene FTO alpha-ketoglutarate-dependent dioxygenase (FTO).
