Table 2. Association with cardiac GWAS SNPs.

	mm9 peaks (OccuPeak)	Hg18 peaks (OccuPeak)	Cardiac SNPs (42)	Control SNPs (504)	Significance
TBX3	163699	99414	8	16	2.19E-05
p300 replicate 1	108397	70949	4	12	8.37E-03
P300 replicate 2	121491	75232	8	15	2.65E-05

Peaks called by OccuPeak for TBX3 and both p300 replicate datasets were converted from the mouse genome (mm9) to the human genome (hg18) to enable overlap analysis with known human SNPs. A two-sample Z-test was performed to test whether called peaks overlap more frequently with SNPs associated with cardiac function than with control SNPs [40]. Control SNPs were randomly selected from a population of SNPs not significantly associated with any GWAS signal and located within 1 Mb of known UCSC genes. SNPs associated with TBX3 peaks are listed, including their phenotype. Further details and references are in the Results section of the main text.