血管紧张素原基因核心启动子区域突变与藏族原发性高血压的关联分析

Association analysis of variants in the core promoter region of angiotensinogen gene with essential hypertension in Tibetan population *

目的 寻找血管紧张素原 (angiotensinogen,AGT)基因核心启动子区域存在的突变 ,分析该突变在中国西藏人群中的分布以及与原发性高血压的关联。方法 以藏族 10 3例原发性高血压患者和 82名健康受试者为研究对象进行病例 -对照研究。用聚合酶链反应 -单链构象多态性 (polymerase chain reaction/singlestrand conformation polymorphism,PCR/SSCP)分析和自动荧光测序方法 ,对 AGT基因核心启动子区域DNA序列进行突变分析 ;用聚合酶链反应 -限制性片段长度多态性 (polymerase chain reaction/restrictionfragmentlength polymorphism,PCR- RFL P)方法分析 AGT基因 (- 6 )位点多态性。结果 PCR/SSCP分析发现 ,AGT基因转录起始位点上游 (- 2 0 )位存在 A→C突变 ,统计分析显示 ,藏族正常人群与高血压人群中该位点 A等位基因均有较高的发生频率 (0 .9175 ,0 .912 4) ,突变位点多态性分布无统计学差异 (P>0 .8)。AGT基因转录起始位点上游 (- 6 )位点存在 A→G突变 ,在藏族正常人群中等位基因 A和 G分布频率分别为 0 .780和 0 .2 2 0 ,原发性高血压群体中它们的分布频率分别为 0 .6 2 6和 0 .374,两者之间存在差异 (P<0 .0 2 5 )。结论(1)藏族群体中 AGT基因 (- 2 0 ) A等位基因有较高的分布频率 ;(2 ) AGT基?

Objective To detect the variants in the core promoter region of angiotensinogen(AGT) gene, and to analyse the relationship between the AGT gene polymorphisms and essential hypertension in Tibetan population. Methods This is a case control study consisting of 103 essential hypertensive subjects and 82 normotensive controls matched by age and sex. The variants in the AGT gene core promoter region were screened by polymerase chain reaction/single strand conformation polymorphism(PCR/SSCP) and further identified by automated sequencing. The A(-6)G polymorphism was determined in DNA extracted from leucocytes by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP). Results (1) There were two different electrophoresis band patterns in PCR/SSCP analysis. PCR product direct sequencing showed that the two band patterns represented the AA, AC genotypes in the (-20) site of AGT gene respectively. The distribution of A(-20)C genotype was almost identical in essential hypertensive and normotensive groups ( P >0.8). The A allele frequency was very high in both groups (control: 0.9175, hypertensive: 0.9124 ). (2)Distribution of genotype in the (-6) site of AGT gene was much different between the patient group and control group ( P <0.005).The frequency of G allele was statistically higher in the patient group than in controls (0.374 vs 0.220, P < 0 025). Conclusion Both Tibetan hypertensives and normotensives have higher frequency of A allele in AGT gene (-20) site. The higher frequency of G allele in the AGT gene (-6) site in Tibetan hypertension patients suggests that this allele may be the genetic susceptibility factor in the proceeding of essential hypertension in the Tibetan population.