Linkage disequilibrium analysis and haplotype block analysis of SNP T1880C, C602A and T1559C. A. Linkage disequilibrium structure and the degree of linkage disequilibrium (D') for each SNP (T1880C, C602A and T1559C) pair. B. LD structure and the degree of linkage disequilibrium (r') for each SNP (T1880C, C602A and T1559C) pair. C. SNPs associating to hypertension and D' haplotype block. 1-T1880C; 2-C602A; 3-T1559C.