Figure 1: 17q21 SNPs overlap immune cell enhancers.

(a) University of California Santa Cruz (UCSC) tracks showing chromosomal location and genes present in the 17q21 locus, containing a large haplotype block of asthma-associated SNPs; the location of asthma-risk SNP rs7216389 is indicated as blue line in the gene track. Black lines indicate SNPs’ genomic location, and red lines are SNPs that overlap peaks of DNase hypersensitivity sites (DHS) from multiple cell types obtained from the ENCODE Encyclopedia (version 2) provided by the ENCODE Project Consortium (see Methods). Exemplary DHS tracks, H3K27ac and H3K4me1 enrichment tracks from CD4⁺ T cells, CD14⁺ monocytes and brain tissue (from ENCODE Project and NIH Epigenomics Roadmap Consortiums) are shown along with UCSC multispecies conservation tracks. (b) Distribution of asthma-associated 17q21 SNPs in different genomic regions. (c) The average number of DHS in the 17q21 locus of immune versus non-immune cell types (n=10 and n=52, respectively) and (d) the 62 primary cell types (indicated as dots, profiled by the ENCODE Project Consortium, see Methods) ordered based on the number of DHS in the 17q21 locus. The top hits and discussed cell types are named and marked in red. (e) Overlap of DHS and 17q21 SNPs. (f) Number of DHS that directly overlap 17q21 SNPs in various cell types (full list in Supplementary Data set 2b). Error bars are mean±s.e.m.; ***P<0.001 by Student’s unpaired two-tailed t-test, and following Bonferroni correction for multiple testing.