甲烯四氢叶酸还原酶基因多态性与糖尿病大血管病变的关系研究

目的探讨甲烯四氢叶酸还原酶(MTHFR)基因C677T位碱基突变与2型糖尿病患者同型半胱氨酸(Hcy)水平和糖尿病大血管病变的关系。方法将患者分为对照组、糖尿病颈动脉内中膜厚度(IMT)正常组、糖尿病IMT增厚组。应用酶联免疫法测定Hcy水平,采用多聚酶链反应-限制性内切酶片段长度多态性技术(PCR-RFLP)检测MTHFRC677T基因型,用高分辨彩色多普勒检查颈动脉内中膜厚度(IMT)。结果糖尿病IMT增厚组MTHFR基因的TT基因型和T等位基因频率显著增高,与糖尿病IMT正常组及对照组存在统计学差异(P<0.05)。对照组与糖尿病IMT正常组之间T等位基因频率无统计学差异。MTHFR基因突变者血浆Hcy增高。糖尿病组MTHFR基因突变者IMT值明显高于无基因突变者。结论糖尿病IMT增厚组T等位基因频率增高。MTHFR基因C677T点突变组血浆Hcy水平升高,颈动脉IMT增厚。推测MTHFR基因C677T点突变可能是糖尿病合并大血管病变发病的重要遗传因素。     

亚甲基四氢叶酸还原酶基因多态性与糖尿病肾病相关性研究

目的：研究亚甲基四氢叶酸还原酶（MTHFR）基因多态性与2型糖尿病肾病的关系。方法：运用聚合酶链反应－限制性片段长度多态性技术（PCR－RFLP）检测85例2型糖尿病患者（其中39例伴糖尿病肾病）及57例正常对照组MTHFR C677T基因型,采用高效液相色谱法测定血浆同型半胱酸水平。结果：糖尿病肾病组MTHFR基因TT纯合基因型,CT杂合基因型及T等位基因频率（分别为38．21％,51．28％,53．85％）均明显高于糖尿病不伴肾病组（分别为19．57％,28．26％,33．70％）及正常对照组（分别为17．54％,28．07％,31．58）,基因型和等位基因频率分布差异均有统计学意义（P＜0．05）,而MTHFR基因该多态性在不伴肾病组与正常对照组之间差异无显著性（P＞0．05）,T等位基因与糖尿病肾病的发生密切相关（OR＝2．30,95％可信区间;1．24－4．26）。糖尿病肾病组,糖尿病不伴肾病组及正常对照组中,MTHFR基因有C677T突变者血浆同型半胱氨酸水平均显著高于无基因突变者。结论：MTHFR基因C677T位碱基突变致血浆同型半胱氨酸水平高是糖尿病肾病发病的重要遗传因素。     

亚甲基四氢叶酸还原酶677C→T及1298A→C基因多态性与糖尿病心血管病变的相关性

目的探讨亚甲基四氢叶酸还原酶(MTHFR)基因多态性与糖尿病心血管并发症(DC)的关系. 方法应用PCR-RFLP法检测84例健康人(NC)和158例2型糖尿病患者[分为无DC(NDC)和DC组]的MTHFR677C→T及1298A→C基因多态性,比较各组间基因型分布和等位基因频率. 结果 DC组MTHFR677 TT基因型分布及T等位基因频率均高于NC或NDC组,且叶酸水平较低(P<0.001); 各组间MTHFR1298A→C基因型分布及等位基因频率差异无统计学意义(P>0.05);MTHFR基因型、年龄是DC的危险因子. 结论 MTHFR677C→T突变与DC的发生有关.     

N5，10-亚甲基四氢叶酸还原酶基因多态性与蒙古族原发性高血压病的关系

目的探讨N5,10-亚甲基四氢叶酸还原酶(MTHFR)C677T位点突变与蒙古族高血压病患者之间的关系。方法采用Sequenom系统检测110例高血压病患者及115例健康对照组MTHFR基因多态性。结果蒙古族高血压人群MTHFR基因TT基因型频率及T等位基因频率(0.15,0.32)与正常人群(0.10,0.29)相比差异无显著性(P>0.05);单纯收缩压增高人群MTHFR基因型TT基因型及T等位基因频率(0.23,0.40)高于正常人群,差异有显著性(P<0.05)。结论MTHFR C677T位点TT基因型及T等位基因突变增加蒙古族人群单纯收缩压增高的危险性,可能是单纯收缩期高血压病的易感基因。     

N5,10-亚甲基四氢叶酸还原酶基因多态性与蒙古族原发性高血压病的关系

目的探讨N5,10-亚甲基四氢叶酸还原酶(MTHFR)C677T位点突变与蒙古族高血压病患者之间的关系.方法采用Sequenom系统检测110例高血压病患者及115例健康对照组MTHFR基因多态性.结果蒙古族高血压人群MTHFR基因TT基因型频率及T等位基因频率(0.15,0.32)与正常人群(0.10,0.29)相比差异无显著性(P＞0.05);单纯收缩压增高人群MTHFR基因型TT基因型及T等位基因频率(0.23,0.40)高于正常人群,差异有显著性(P＜0.05).结论MTHFR C677T位点TT基因型及T等位基因突变增加蒙古族人群单纯收缩压增高的危险性,可能是单纯收缩期高血压病的易感基因.     

N5,10-亚甲基四氢叶酸还原酶基因多态性与蒙古族原发性高血压及高血压合并脑血管病的关系

该文探讨亚甲基四氢叶酸还原酶(MTHFR)C677T位点突变与蒙古族原发性高血压及高血压合并脑血管病患者之间的关系。方法:采用Se-quenom系统检测110例蒙古族(长期生活在内蒙古乌拉特后旗的三代血亲无其他民族的蒙古族人群)原发性高血压患者、78名高血压合并脑血管病患者及115例健康对照组MTHFR基因多态性。结果:蒙古族原发性高血压人群MTHFR基因TT基因型频率及T等位基因频率与正常人群相比差异无显著性(P>0.05);蒙古族高血压合并脑梗死人群与高血压合并脑出血人群的MTHFR基因型TT基因型及T等位基因频率分别明显高于正常对照组,有显…     

同型半胱氨酸代谢关键酶基因多态性与2型糖尿病合并冠心病的关系

目的探讨我国北方地区汉族人同型半胱氨酸(Hcy)代谢相关酶(MTHFR C677T、CBS844ins68)基因多态性的特点及基因多态性与2型糖尿病(T2DM)合并冠心病(CHD)的关系。方法研究对象均为北方汉族人群,包括无血缘关系的105例T2DM合并CHD患者、125例单纯T2DM患者和91例健康对照组。应用分子生物学方法分析MTHFR C677T、CBS844ins68基因多态性。结果T2DM合并CHD组的T等位基因频率明显高于与对照组(45.3%vs34.6%,P<0.05),其中CT基因型频率高于对照组(58.1%vs38.5%,P<0.05),CC型频率明显低于对照组(25.7%vs46.2%,P<0.05)。CBS844ins68多态性三组CBS844ins68的基因型及等位基因频率差别均无统计学意义(均P>0.05)。Logistic回归分析显示MTHFR基因型的OR值为1.394,95%CI0.989-1.965(P=0.058);MTHFR677携带T基因(MTHFR CT基因型和TT基因型)的OR值为1.939,95%CI1.159-3.243(P=0.012);CBS的OR值为0.52,95%CI0.108-2.495(P=0.414)。结论MTHFR677携带T基因是我国北方地区汉族人T2DM合并CHD发生的独立危险因素,筛查MTHFR677T基因型可能在预防糖尿病合并冠心病的发生、发展过程中起到一定作用。     

2型糖尿病合并脑梗塞患者的MTHFR基因、eNOS基因多态性位点的联合研究

目的探讨N5,10-亚甲基四氢叶酸还原酶（MTHFR）基因C677T位点、内皮型一氧化氮合酶（eNOS）基因G894T位点与2型糖尿病合并脑梗塞的关系。方法采用Sequenom系统检测内蒙古地区汉族健康对照组65人、2型糖尿病患者34例、2型糖尿病合并脑梗塞患者42例的MTHFR、eNOS基因型。结果（1）eNOS基因G894T位点2型糖尿病合并脑梗组TT基因型频率、T等位基因频率与对照组比较差异有显著性（P〈0．01,P〈0．01）;2型糖尿病合并脑梗组T等位基因频率与糖尿病组比较差异有显著性（P〈0．05）,（2）MTHFR基因C677T位点的TT基因型与eNOS基因G894T位点的TT基因型在2型糖尿病人群患脑梗塞方面具有协同作用（P〈0．05）。结论MTHFR基因C677T位点和eNOS基因G894T位点变异增加糖尿病患者发生脑梗的危险性,可能是糖尿病患者发生脑梗塞的遗传易感基因。     

亚甲基四氢叶酸还原酶基因多态性与原发性高血压患者合并冠心病的相关性研究

目的探讨N5,10-亚甲基四氢叶酸还原酶(MTHFR)C677T位点突变与河南豫北地区原发性高血压及其合并冠心病发病的关系。方法选择原发性高血压患者405例为高血压组,高血压合并冠心病患者400例为冠心病组,健康体检者400例为对照组。对3组MTHFR基因C677T多态性进行基因分型。结果冠心病组T等位基因频率和TT基因型频率明显高于高血压组和对照组(P<0.05)。冠心病组TT基因型患者TC和血浆同型半胱氨酸水平明显高于CC+CT基因型(P<0.05)。结论 MTHFR基因C677T多态性与原发性高血压患者冠心病的发生相关。     

N5，N10-亚甲基四氢叶酸还原酶基因多态性及血浆同型半胱氨酸与冠心病的关系

目的研究N5,N10-亚甲基四氢叶酸还原酶(MTHFR)基因C677T多态性、血浆同型半胱氨酸(Hcy)与冠心病的关系。方法选取2013年至2015年在我院住院的冠心病患者256例,按年龄分为60岁组(中青年组)107例及≥60岁组(老年组)149例,选取同期行健康体检的人群145例作为对照组,应用聚合酶链反应(PCR)技术和基因芯片分析技术检测MTHFR基因C677T多态性,应用高效液相色谱法测定血浆Hcy水平,分析不同组群之间MTHFR基因C677T多态性的分布及Hcy水平。结果 MTHFR基因分布频率:中青年组CC型、CT型、TT型基因频率分别为26.2%,43.9%,29.9%,C等位基因频率为48.1%,T等位基因频率为51.9%。中青年组CC型、CT型、TT型基因频率分别为35.6%,42.3%,22.1%,C等位基因频率为56.8%,T等位基因频率为43.2%。对照组CC型、CT型、TT型基因频率分别为37.9%,40.1%,21.4%,C等位基因频率为58.3%,T等位基因频率为41.7%。中青年组T等位基因频率明显高于对照组(χ~2=5.10,P=0.015),中青年组Hcy浓度明显高于对照组。老年组T等位基因频率与对照组比较差异无显著性(χ~2=0.147,P=0.382),两组间Hcy浓度差异无显著性。各组的TT基因型者血浆Hcy浓度均明显高于CC和TC基因型者(P0.01),而后两者间差异无显著性。结论 MTHFR基因TT型可导致Hcy水平明显升高,MTHFR基因C677T点突变仅与中青年组冠心病患者相关,与老年组冠心病患者无明显相关,Hcy水平升高及MTHFR基因T等位基因频率增高可能为中青年冠心病患者的危险因素,提示不同年龄阶段的冠心病患者发病的机制可能存在差异。     

2型糖尿病肾病亚甲基四氢叶酸还原酶基因多态性研究

目的探讨亚甲基四氢叶酸还原酶(methylenetetrahydrofolate     

Genetic polymorphism of methylenetetrahydrofolate reductase as a risk factor for diabetic nephropathy in Chinese type 2 diabetic patients

OBJECTIVE: Genetic predisposition has been implicated in diabetic nephropathy (DN). The C677T variant of the methylenetetrahydrofolate reductase (MTHFR) gene, one of the key enzymes catalyzing remethylation of homocysteine, may play a role in the development of not only vascular disease but also diabetic microangiopathies. In this study, we examined the distribution of the MTHFR genotypes in the Chinese population and the association between the C677T variant and diabetic nephropathy. METHODS: 220 unrelated patients with type 2 diabetes mellitus and 130 controls were recruited. The MTHFR genotype was analyzed by PCR followed by HinfI digestion. Plasma total homocysteine levels were measured using high-performance liquid chromatography (HPLC) with fluorescence detection. RESULTS: In 130 healthy control subjects, the frequency of the mutant T allele was 30.0%, comparable to that of a Hong Kong (Chinese) population. The distribution of the three genotypes was as follows: TT genotype, 16.9%; CT genotype, 26.2%; and CC genotype, 56.9%. This genotype distribution did not differ between control subjects and type 2 diabetic patients in which 19.1% were TT, 34.5% were CT and 46.4% were CC (2=3.85, P>0.05). The frequency of the mutant T allele was 42.3% in diabetic patients with nephropathy (n=124) versus 28.6% in those without nephropathy (n=96). The genotype frequencies were TT, 21.0%; CT, 42.7%; CC, 36.3% in diabetic patients with nephropathy versus TT, 16.7%; CT, 23.9%; CC, 59.4% in those without nephropathy. The MTHFR genotype and allele frequencies were different between diabetic patients with and without nephropathy (chi2=12.27, P<0.005; chi2=8.77, P<0.005, respectively). Moreover, plasma homocysteine levels were markedly higher in individuals with TT genotype than those with CC or CT genotype. CONCLUSIONS: The C677T mutation of MTHFR gene is common in the Chinese population. MTHFR C677T gene polymorphism associated with a predisposition to increased plasma homocysteine levels may represent a genetic risk factor for diabetic nephropathy in Chinese type 2 diabetic patients.     

The relationship of the methylenetetrahydrofolate reductase C677T gene polymorphism in Turkish type 2 diabetic patients with and without nephropathy

BACKGROUND: Poor glycaemic control, hypertension and duration of diabetes are risk factors for the development of diabetic nephropathy, but there may be genetic factors. Recently, a common C to T mutation at nucleotide position 677 of the MTHFR gene (MTHFR677C > T) has been reported to be correlated with hyperhomocysteinemia and the severity of coronary artery disease as macroangiopathy. We aim to investigate Turkish type 2 diabetic patients with/without diabetic nephropathy and healthy group and examine the contribution of the MTHFR gene polymorphism to the development of diabetic nephropathy. METHODS: DNA was extracted from peripheral leukocytes of the subjects. Genotyping of the MTHFR C677T polymorphism for all individuals was performed by melting curve analysis of the generated amplicons after real-time online PCR. RESULTS: This genotype distribution did not differ between control subjects and type 2 diabetic patients in which 6.8% were TT, 43.7% were CT and 49.5% were CC (chi2 = 0.201, p > 0.05). The frequency of the mutant T allele was 23.4% in diabetic patients with nephropathy versus 33.0% in those without nephropathy. The genotype frequencies were TT, 2.1%; CT, 46.6%; CC, 55.3% in diabetic patients with nephropathy versus TT, 10.7%; CT, 44.6%; CC, 44.6% in those without nephropathy. CONCLUSIONS: The MTHFR genotype and allele frequencies were not different between diabetic patients with and without nephropathy (chi2 = 3, 386, p > 0.005; chi2 = 2.320, p > 0.005, respectively). Therefore, we conclude that the MTHFR gene polymorphism is not associated with the development of diabetic nephropathy in Turkish type 2 diabetic patients.     

亚甲基四氢叶酸还原酶基因多态性与2型糖尿病微血管病变易感性的研究

目的 探讨亚甲基四氢叶酸还原酶（methylenetetrahydrofolate reductase,MTHFR)基因多态性与中国北方汉族2型糖尿病患者微血管并发症（DMAP）易感性的关系。方法 应用聚合酶链反应－限制性片段长度多态性（PCR－RFLP）的方法检测291名中国北方汉族[2型糖尿病患者229例,其中无微血管并发症（NCD）组102例,糖尿病视网膜病变（DR）组60例,糖尿病肾病（DN）组和67例;健康人对照（CON）组62例]MTHFR基因的多态性,比较各组间MTHFR等位基因和基因型的频率。结果 基因型BB在DN及DR组（34．3％和31．7％）高于NCD组和CON组（13．7％和12．9％）;DN及DR组的等位基因B频率（54．4％和59．9％）,也高于NCD组和CON组（41．2％和35．5％）,差异均有显著性意义。基因型BB和等位基因B在NCD和CON组之间的分布无统计学差异。结论 MTHFR基因C677T变异与中国北方汉族2型DM患者DMAP的发生有关。等位基因B可能是DMAP的易感基因。     

No association between MTHFR gene polymorphism and diabetic nephropathy in Japanese type II diabetic patients with proliferative diabetic retinopathy

The development of diabetic nephropathy shows marked variation among individuals. Not only hyperglycemia, but also genetic factors may contribute to the development of diabetic nephropathy. Methylenetetrahydrofolate reductase (MTHFR) is involved in remethylation of homocysteine to methionine. Decreased activity of MTHFR which can result in hyperhomocysteinemia may lead to cerebrovascular disease and coronary artery disease. Recently, a common C to T mutation at nucleotide position 677 of the MTHFR gene (MTHFR677C>T) has been reported to be correlated with hyperhomocysteinemia and the severity of coronary artery disease as macroangiopathy. In the present study, we recruited 173 of Japanese type II diabetic patients with proliferative diabetic retinopathy who would be exposed to long-term hyperglycemia, and examined the contribution of the MTHFR gene polymorphism to the development of diabetic nephropathy as microangiopathy. The frequency of the mutated allele was 43.3% in patients with nephropathy (n = 105) versus 41.9% in those without nephropathy (n = 68). The genotype frequencies were +/+, 16.2%; +/−, 54.3%; −/−, 29.5% in patients with nephropathy versus +/+, 13.2%; +/−, 57.4%; −/−, 29.4% in those without nephropathy (+ indicates the presence of the mutation). The MTHFR genotype and allele frequencies were not significantly different between patients with and without nephropathy. Therefore, we conclude that the MTHFR gene polymorphism is not associated with the development of diabetic nephropathy in Japanese type II diabetic patients.     

基质金属蛋白酶9基因多态性与2型糖尿病血管病变的相关性研究

目的 探讨基质金属蛋白酶9(MMP-9)基因C-1562T多态性与2型糖尿痫血管病变的关系．方法 运用PCR-RFLP检测110名健康对照者和450例2型糖尿病(DM)患者(其中单纯2型DM者100例、大血管病变者120例、糖尿病肾病(DN)患者130例、糖尿病视网膜病变患者100例)的MMP-9基因型，比较各组的基因型和等位基因频率。结果 (1)所有糖尿病视网膜病变患者的基因型均为CC型。(2)与对照组和单纯2型DM组相比，大血管病变组的T基因型和T等位基因频率显著升高，而DN组的TT基因型和T等位基因频率明显下降。(3)Logistic回归分析显示MMP-9 T等位基因、血清MMP-9、总胆固醇、低密度脂蛋白胆固醇、脂蛋白(a)是大血管病变发生的危险因素；尿白蛋白排泄率、脂蛋白(a)、HbA1C是DN发生的危险因素。结论 MMP-9基因C-1562T多态性与2型DM血管病变的发生有关，T等位基因是大血管病变的易感基因，是DN的保护基因。     

The association between end-stage diabetic nephropathy and methylenetetrahydrofolate reductase genotype with macroangiopathy in type 2 diabetes mellitus.

The T/T genotype of the methylenetetrahydrofolate reductase C677 T gene polymorphism is associated with elevated homocysteine levels and presumably with increased atherosclerotic risk. We evaluated the interaction between this gene polymorphism and end-stage diabetic nephropathy on the observed prevalence of macroangiopathy in type 2 diabetes mellitus. The methylenetetrahydrofolate reductase 677 C/T genotypes were determined in 174 type 2 diabetic patients: 80 with and 94 without renal failure due to diabetic nephropathy. In the patients with renal failure, the T/T genotype and T allele were significantly associated with macroangiopathy (T/T; 31 % vs. 2 %, P = 0.0001 T allele; 59 % vs. 29 %, P = 0.00014), whereas the associations were not significant in the patients without renal failure. In the multiple logistic regression analysis, age (10 years OR 4.05 [1.79 - 9.31], P < 0.0005) and 677 T allele (6.84 [2.12 - 22.05], P = 0.0013) were significantly associated with macroangiopathy in the patients with renal failure. In conclusion, this study demonstrated that the 677 T/T genotype and T allele of MTHFR were significantly associated with macroangiopathy in type 2 diabetic patients with renal failure. The MTHFR 677 T allele, together with renal dysfunction due to diabetic nephropathy, could be a strong risk factor for atherosclerotic disease.     

中国人2型糖尿病微血管并发症与AGE受体基因Gly82Ser多态性相关研究

目的　探讨 AGE受体 (RAGE)基因 Gly82 Ser多态性与中国人 2型糖尿病微血管并发症间的关系。方法　使用限制性内切酶 Alu I(AG↑ CT)的 PCR- RFL P法 ,检测 10 4例非糖尿病对照者和 15 6例 2型糖尿病伴或不伴肾病、视网膜病变者的 RAGE基因 Gly82 Ser的多态基因型。结果　中国人 RAGE基因 Gly82 Ser多态基因型以 GG型、等位基因以 G型为最多见 ,但频率分布与白种人相比有显著性差异。非 DM对照组与 2型糖尿病伴或不伴有肾病的 4个亚组间、与伴或不伴有视网膜病变的 2个亚组间 ,RAGE基因的 Gly82 Ser多态的基因型 (GG、GS、SS)频率或等位基因 (G、S)频率皆无显著性差异 (Fisher's确切 P值 >0 .0 5 )。结论　 RAGE基因的 Gly82 Ser多态引起的 RAGE功能性氨基酸突变与 2型糖尿病微血管并发症的发生及进展无显著性相关     

MTHFR gene polymorphism is susceptible to diabetic retinopathy but not to diabetic nephropathy in Japanese type 2 diabetic patients

AIMS: Previously, we have proposed that methylenetetrahydrofolate reductase (MTHFR) gene polymorphism (C677T) could be a risk factor for diabetic retinopathy. To support our suggestion, we examined in detail the association of MTHFR polymorphism with diabetic retinopathy and nephropathy in Japanese type 2 diabetic patients. METHODS: Subjects (n=190) were free of cardiovascular diseases and were not on hemodialysis. Retinopathy was assessed according to fundamental differentiation; nephropathy was determined according to urinary albumin level; and MTHFR genotype was determined by polymerase chain reaction-restriction fragment length polymorphism. We also analyzed how hyperglycemia affected these three conditions in 131 patients with glycosylated hemoglobin > or =6.5% and fasting blood sugar > or =110 mg/dl. RESULTS: The frequency of 677T/677T homozygous subjects with retinopathy was higher than the frequencies of the other two genotypes, and a significant difference was observed in the distribution of the genotypes (677C/677C, 41.9%; 677C/677T, 31.1%; 677T/677T, 61.5%; P<.05). The susceptibility of 677T/677T homozygote to retinopathy approached significance [odds ratio (OR)=2.17; 95% confidence interval (95% CI)=0.87-5.42]. However, in the population with hyperglycemia, the 677T/677T homozygote modified the risk for retinopathy (OR=4.30; 95% CI=1.42-13.1), especially the risk for nonproliferative retinopathy. In contrast, the 677T/677T homozygote did not affect the risk for nephropathy (OR=1.17; 95% CI=0.45-3.05), even in subjects with hyperglycemia (OR=1.50; 95% CI=0.50-4.48). CONCLUSIONS: Our results are highly suggestive of an important role for MTHFR genotype in susceptibility to retinopathy under hyperglycemia, but not to nephropathy. Preventive therapies based on MTHFR polymorphism could delay the onset of retinopathy in type 2 diabetic patients.