内皮细胞型一氧化氮合酶基因多态性与糖尿病肾病的相关性研究

目的：探讨内皮细胞型一氧化氮合酶（eNOS)基因第7外显子894G→T点突变,及其第4内含子的1个27bp的插入／缺失（a/b)多态性,与2型糖尿病肾病（DN）之间的关系。方法：894G→T点突变采用聚合酶链反应限制性片段长度多态性（PCR－RFLP）技术,27bp的a/b多态性采用聚合酶链反应结合4％琼脂糖凝胶电泳分离技术。比较各组间的等位基因频率与基因型频率。结果：（1）早期糖尿病肾病组（DN^ 组）T等位基因及TG基因型频率显著高于糖尿病非肾病患者（DN^-组,P＜0．05）。（2）DN^ 组a等位基因及ab基因型频率显著高于DN^-组（P＜0．05）。（3）DN^ 组的TGab基因型频率亦显著高于DN^-组（P＜0．05）。（4）糖基化血红蛋白（GHbA1c),收缩压（SBP）,总胆固醇（TC）,eNOS基因第7外显子894G→T基因点突变及第4内含子a/b多态性均属糖尿病肾病的独立危险因素。结论：糖尿病患者eNOS基因第7外显子T等位基因及第4内含子a等位基因与DN^ 的发生密切相关,两种等位基因同时存在者,DN^ 发病风险更高。

The association between polymorphism of endothelial nitric oxide synthase gene and diabetic nephropathy

OBJECTIVE: To investigate the association between a 894 G-->T mutation at exon 7 and a 27 base pair(bp) repeat polymorphism in intron 4 of the eNOS gene and diabetic nephropathy in Chinese. METHODS: A case control study of 228 Chinese subjects (including 143 type 2 diabetes mellitus with or without nephropathy and 85 normal controls) was performed. The number of 894 G-->T mutation allele and 27 bp repeat polymorhism alleles were determined by polymerasechain reaction restriction fragment lenth polymorphism(PCR-RFLP) method and PCR combined with 4% agarose electrophoresis. RESULTS: The frequency of the T allele and TG genotype at exon 7 and the a allele and ab genotype in intron 4 were significantly higher in diabetic nephropathy positive (DN+) group than in diabetic nephropathy negative (DN-) group and control subjects(P < 0.05). Diabetic patients with coexistence of the T and a alleles had a higher incidence of diabetic nephropathy(P < 0.05) than those with only one of the two alleles or without any of the two alleles. Multivariate logistic regression analysis showed that blood glucose, GHbA1c, SBP, TC, 894 G-->T mutation at exon 7 and a 27 base pair(bp) repeat polymorphism in intron 4 of the eNOS gene are independent risk factors for diabetic nephropathy. CONCLUSIONS: The T allele at exon 7 and a allele in intron 4 are related to diabetic nephropathy in Chinese patients with type with 2 diabetes mellitus. The incidence of diabetic nephropathy is higher in patients who have both T and a alleles than patients who have either T or a allele alone.