Figure 1.

Two-stage study design. Four pools (A-D) of a total of 490 case and 490 control samples were created and subjected to a GWAS in the discovery phase. Each case-control pool set generated a list of SNPs passing the Bonferroni-corrected cut-off. 19 SNPs which consistently appeared in multiple lists were short-listed for replication. Following individual genotyping in 521 case and 524 control samples, 2 SNPs remained significantly associated. These SNPs were subsequently genotyped in the 490 case and 490 control samples to make up a total of 1011 case and 1014 control samples. An additional 1445 atopy control samples were also genotyped.