Figure 1
Genomic landscape of the atrial-fibrillation associated region 4q25. (A) A 230 kb view of the 4q25 (hg19; chr4:111,516,448-111,747,857) gene desert, showing the position of AF risk-associated SNPs (vertical black bars) distal to PITX2. The different PITX2 isoforms of the gene are shown above with PITX2c, the main cardiac isoform, on top. Below, UCSC tracks of the region showing the distribution of H3K4me1 marks (me1) in foetal heart (FH), smooth muscle (SM), foetal liver (FL), foetal brain (FB) and human embryonic stem cells (H1); the conservation (cons) between human and mouse, rat, cow, opossum and chicken; and the linkage disequilibrium structure from the HapMap Project (CEU r2). (B) A 85 kb zoom of the shaded rectangle shown in A (hg19; chr4:111,662,786-111,747,668) indicating the fragments (AF1-AF7) tested for regulatory activity in this study. The lead AF risk associated SNP rs2200733 is highlighted in red. AF, atrial fibrillation; UCSC, University of California Santa Cruz genome browser.