Genome-wide association studies - A summary for the clinical gastroenterologist

Figure 1 Example of cluster plots for two SNPs. Plot A shows the plotting of the normalized intensity values for a SNP with good clustering. Each color represents the respective genotype (blue for GG, green for AG and red for AA). Plot B demonstrates the cluster plot for a SNP with bad clustering (same color coding as in A). Disease-associated SNPs demonstrating cluster plots as in B should be discarded as the significant associations at such SNPs are most likely technical artifacts.

Figure 2 Power calculations for different case-control study panel sizes. Power calculations for different case-control study panel sizes using an allelic based association test and a P-value of P < 5 × 10^-7. All calculations assume a minor allele frequency of 30% and 1:2 ratio of cases vs controls.

Figure 3 Historical milestones in Crohn’s disease genetics. Developments in the knowledge of the genetics of Crohn’s disease. Only milestone gene discoveries are shown. With the publication of the Crohn’s disease meta-analysis in 2009 the number of replicated loci is now greater than 30.