Relationship between four single nucleotide polymorphisms of epithelial sodium channel alpha subunit gene and essential hypertension of Kazakhs in Xinjiang / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the relationship between G2139A,G3091A, T663A, and T3593C single nucleotide polymorphisms (SNPs), which are located at the promoter region,13th exon, and 2nd intron of epithelial sodium channel (ENaC) gene, and their haplotypes with essential hypertension (EH) in Kazakhs in Xinjiang.</p><p><b>METHODS</b>A case-control study was conducted including 252 EH patients (EH group) and 254 normotensive subjects (NT group) among Kazakhs in Xinjiang. The four genetic polymorphisms were identified by polymerase chain reaction - restriction fragment length polymorphism. The distribution of the genotypes and alleles in all subjects and the different frequency of these four SNPs between EH group and NT group were analyzed. The linkage disequilibrium and haplotypes of these four SNPs were analyzed.</p><p><b>RESULTS</b>These four SNPs of alpha ENaC gene existed in Xinjiang Kazakhs. In all subjects, the distribution frequencies of genotypes AA, AG, and GG at G2139A were 26.2%, 52.3%, and 21.5%, respectively, and those of alleles (A, G) were 52.37% and 47.63%. The distribution frequencies of genotypes AA, AG, and GG at G3091A were 19.0%, 52.5%, and 28.5%, respectively, and those of and alleles (A, G) were 45.56% and 59.44%. The distribution frequencies of genotypes AA, AG, and GG at T663A were 15.6%, 49.9%, and 34.5%, respectively, and those of alleles (A, G) were 40.53% and 59.47%. The distribution frequencies of genotypes TT, TC, and CC at T3593C were 88.5%, 10.5%, and 1.0%, respectively, and those of alleles (T, C) were 93.77% and 6.23%. The distribution of genotypes at these four SNPs were all consistent with Hardy-Weinberg equilibrium in this population (P0.05). The distribution frequencies of genotypes and alleles about these four genetic polymorphisms were not significantly different between the EH group and NT group (P0.05). However, the frequencies of two haplotypes were found to be significantly different between these two groups (P0.05). The haplotype frequency which included 2139G, 3091A, 663G, and 3593T alleles was significantly increased in EH group (P0.01), while the haplotype frequency which included 2139A, 3091A, 663A, and 3593C alleles was significantly increased in NT group (P0.05).</p><p><b>CONCLUSIONS</b>The haplotypes that are composed of G2139A, G3091A, T663A, and T3593C polymorphisms of alphaENaC gene may play an important role in the development of EH among Kazakhs in Xinjiang. The haplotypes that are composed of 2139G, 3091A, 663G, and 3593T alleles may aggravate the development of EH. The haplotypes that composed of 2139A, 3091A, 663A, and 3593C alleles may decrease the risk of EH among Kazakhs.</p>

The relationship between the variants in 5' upstream core promoter A(-6)G and A(-20)C of angiotensinogen gene and essential hypertension in Kazakans of Xinjiang / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>T 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.</p><p><b>RESULTS</b>(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.</p><p><b>CONCLUSION</b>The 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.</p>