Fig. 1 (Fig. 1 in original article [1])

Display of the MDR Results for a Three-SNP Interaction. This figure illustrates the solution dataset for a run of our algorithm which attempted to create a three-marker dataset with a high third-order gene-disease association and no lower-level effects. Each square in the plots represents a specific genotypic combination. Within each square the first bar measures the number of cases and the second bar measures the number of controls. The darker squares represent a genotypic combination that was considered high-risk due to the greater number of cases than controls contained within. The top panel, labeled a, shows the relation between each single marker and case–control status. The ability of our algorithm to minimize first-order associations is visible by the relatively equal height of the bars within each square. Of the three one-way associations, X1 versus case–control status scored the highest with an accuracy of 0.502. The middle panel, labeled b, shows the relation between all three two-locus combinations and disease. Again our algorithm succeeded in preventing any major ability to classify disease status based on a specific genotypic combination. The highest two-way effect was between X1, X2 and disease with an accuracy of 0.513. The bottom panel, labeled c, shows the subjects fully decomposed into all genotypic combinations illustrating the third-order effect. Under this level of analysis, each genotypic combination expresses great ability to differentiate between cases an controls. As desired, the accuracy was high at 0.804