Fig. 1. Block structure of linkage disequilibrium for the 28 successfully genotyped single nucleotide polymorphisms (SNPs) in the natriuretic peptide precursor protein A and B gene regions ( NPPA/NPPB ) on chromosome 1p36.22. SNPs surrounded by boxes are the SNPs that were significantly associated with the ventricular dysfunction phenotype after adjustment for clinical covariates and multiple comparisons ( P < 0.05). Stronger correlations between SNPs are noted by darker color in the intersecting squares linking each pair of SNPs. Stronger correlation indicates a tendency for the minor allele of one SNP to be inherited with the minor allele of the other SNP that it is being linked with in this figure. Correlations and block structures were estimated using Haploview (version 4.1; The Broad Institute, Cambridge, MA). 30