Fig. 2

Hierarchical clustering of NHGRI human traits. a Dendrogram and heat map of similarity for pairwise human traits. The hierarchical dendrogram was constructed based on the Chao–Sorensen similarity index, and significance of similarity was measured using a hypergeometric test implemented in the CPAG program. A total of 317 traits having at least one significant association (p < 0.05) against other traits were included. Colors in the heat map are based on the Chao–Sorensen index and scaled according to the color key. Colored blocks along the y-axis of the heat map are indicative of the nine assigned categories of traits. Enlarged versions of an autoimmune cluster (b), obesity cluster (c) and atherosclerosis cluster (d) are shown. Additional file 4 contains a higher resolution dendrogram and heat map with all 317 traits labeled