OBJECTIVETo investigate whether the variants A(-6)G and A(-20)C of angiotensinogen (AGT) gene are involved in the pathogenesis of essential hypertension in Kazakans.

METHODST his case control study recruited 125 subjects with hypertension and 74 normotensive subjects from Kazakans of Xinjiang. Genomic DNA from leukocytes was analyzed for genetic variants A(-6)G and A(-20)C in 5' upstream core promoter of AGT gene by polymerase chain reaction (PCR), single strand conformation polymorphism (SSCP), restriction fragment length polymorphism (RFLP) and automatic sequencing.

RESULTS(1)There were only A(-6)G and A(-20)C variants in the -164 to +73 region of Kazakans' AGT gene. (2) The distributions of genotypes AA, AG, GG at locus -6 of AGT gene showed significant difference between the hypertensive group (0.39, 0.45, 0.16) and the normotensive group (0.49, 0.49, 0.02; Chi2=8.56, P=0.014). There were evident differences in the frequencies of the -6A and the -6G allele of the two groups (0.62, 0.38 and 0.73, 0.27; Chi2=5.35, P=0.021). (3) No significant difference was observed in the distribution of genotypes AA, AC, CC at locus -20 of AGT gene between the hypertensive group (0.69, 0.26, 0.05) and the normotensive group (0.65, 0.32, 0.03; Chi2=2.42, P=0.30). There was no distinct difference in the frequencies of the -20A allele and the -20C allele of the two groups (0.82, 0.18 and 0.82, 0.18; Chi2=0, P=0.99). (4) No significant difference was found at the levels of systolic and diastolic blood pressure between the groups corresponding to genotypes at the loci -6 and -20 of AGT gene.

CONCLUSIONThe results suggest that the polymorphism of A(-6)G in 5' upstream core promoter of the AGT gene may be involved in the pathogenesis of essential hypertension in Kazakans, while the A(-20)C variant may not play an important role in the etiology of essential hypertension in Kazakans.