Three single-nucleotide polymorphisms of the angiotensinogen gene and susceptibility to hypertension: single locus genotype vs. haplotype analysis

1 Graduate Institute of Physiology, National Taiwan University College of Medicine, Taipei 100, Taiwan 2 Department of Internal Medicine, National Taiwan University Hospital, Taipei 100, Taiwan 3 Institute of Epidemiology, National Taiwan University College of Public Health, Taipei 100, Taiwan Although some single polymorphism analyses of the angiotensinogen (AGT) gene have been found to be associated with hypertension, the results are still inconsistent. The objectives of this study are to evaluate the association of the genotype and haplotype distributions of three single-nucleotide polymorphisms (SNPs) (G–217A, A–6G, and M235T) in the AGT gene with hypertension. In a sample of 461 hypertensive and 327 normotensive patients in Taiwan, we found that –217AA and –6GG homozygotes conferred independently an increased risk to hypertension ( P = 0.008 and P = 0.037, respectively), as illustrated by their significant associations with hypertension in both single SNP and pair-wise SNPs analyses. Meanwhile, a very weak linkage disequilibrium was found between the G–217A and the A–6G polymorphisms in terms of r 2 (