| Objective:Many studies have shown an association of single nucleotide polymor-phisms(SNPs) in the angiotensinogen(AGT) gene with essential hypertension (EH).Hypertension is a risk factor for left ventricular hypertrophy(LVH) and animal models suggests that AGT may play a role in the growth and hypertrophy of the heart. Here,a case-control study was used to explore the associations of the -6A/G,-20A/C, M235T,and T174M genetic polymorphisms of AGT with the hypertensive LVH in Kazakans.Methods:The study subjects were selected randomly from patients with EH involved in our Hypertension-related cohort.In Xinjiang province.All patients are Kazakans.aged 30 to 60 years.LVH was evaluated by the electrocardiography voltage criteria and the Romhilt-Estespoint-score system.Finally,total 310 subjects with EH (107 with left ventricular hypertrophy,203 non-left ventricular hypertrophy) was involved in this study.The index of hypertensive subjects were selected on the basis of the following criteria:1) systolic blood pressure≥150 or diastolic blood pressure≥95 mm Hg,or both.2).Free of secondary hypertension due to renal insufficiency or diabetes mellitus.Genomic DNA was conventionally extracted from the peripheral blood leukocytes by proteinase K digestion of nuclei.Phenol extraction was followed by ethanol precipitation of the DNA.The genotypes were determined by using PCR-RFLP. Statistical analyses were performed with SPSS,version12.0.A P value of＜0.05 was considered statistically significant.Differences in the genotypes arid Allele frequencies between groups were determined with the x~2 procedure.Group mean values were compared with the use of the t or F test procedure.Estimation of haplotypes frequency and analysis of Linkage Disequilibrium were performed with SNPstats softwares. Results:(1) We confirmed that M235T,T174M,-20 A/C,and -6 A/G genetic polymorphisms are also exist in Kazakans.All of genotype distributions of the four polymorphisms were in Hardy- Weinberg equilibrium.(2) Both of genotypes and alleles frequencies of M235T and T174M had no significant differences between LVH and NLVH with EH(P＞0.05);(3) When to analyze the tendency in frequencies of genotypes and alleles of M235T,T174M according to gender,it was still not found significant differences in LVH and NLVH(P＞0.05).However,we found a significant difference of genotypes and alleles frequencies on -6A/G between LVH and NLVH in female(P＜0.05), for -20A/C,the difference could only be found in male(P＜0.05).(4) Pair wise LD analysis found there were significant linkage disequilibrium among -6 A/G,-20 A/C, M235T and T174M apart from between M235T and 174M.(5) 11 haplotypes were observed in our population,and We found 11 haplotypes were higher than 1%,which could explain almost 100.00%chromosomes.The most common haplotypes -20A—-6A—174T—235M(32.81%),next -20A—-6G—174T—235M(29.34%).(6)We found the frequency of H2(A-G-M-T),H5(C-A-M-M),H6(C-A-T-T)and H9(C-A-T-M) was significantly difference between LVH and NLVH(P＜0.05).Conclusion:Our study suggest that the -6A/G,-20A/C,M235T and T174M variants of AGT gene might play a role in the LVH with essential hypertension in Kazakans of xinjiang. |
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