颈动脉粥样硬化超声表现与同型半胱氨酸及MTHFR基因多态性的相关性

目的 探讨颈动脉粥样硬化超声表现与血浆同型半胱氨酸(Hcy)及MTHFR C677T基因多态性之间的相关性。方法 143例颈动脉粥样硬化患者作为动脉硬化组,再进一步细分为内膜增厚亚组(75例)与斑块亚组(68例),选择91名无颈动脉内膜增厚及斑块形成者作为对照组。对所有研究对象均进行血浆Hcy及MTHFR C677T基因多态性检测。结果 MTHFR C677T基因CC、CT及TT型血浆Hcy水平依次逐渐升高,各组间差异有统计学意义(P<0.05)。血浆Hcy是颈动脉粥样硬化的独立危险因素(P<0.05),而MTHFR C677T基因多态性未进入回归方程。结论 血浆Hcy升高是颈动脉粥样硬化的独立危险因素;MTHFR C677T基因多态性在颈动脉粥样硬化与正常人群中分布不同,并与血浆Hcy水平相关,但不是颈动脉粥样硬化的独立危险因素。     

Prevalence of methylenetetrahydrofolate reductase mutations in patients with venous thrombosis.

BACKGROUND: The objectives of this study are to examine the prevalence of combined methylenetetrahydrofolate reductase (MTHFR) 677C-->T and 1298A-->C mutations in patients with venous thrombosis (VT) and healthy volunteers and to determine if these mutations are in Hardy-Weinberg equilibrium. METHODS AND RESULTS: Sixty-five patients with VT and 64 healthy volunteers were assessed for MTHFR 677T and 1298C alleles using polymerase chain reaction and restriction fragment length polymorphism. Observed MTHFR genotype frequencies were compared with expected genotype combinations, and their odds ratios were determined. MTHFR allele frequency did not differ between VT and control groups; however, differences were observed for MTHFR genotype distribution. MTHFR 677T and 1298C alleles occurred in cis in our population, and therefore mutation crossover has occurred. There was deviation from the Hardy-Weinberg equilibrium for combined MTHFR genotypes, although this may at least partly be attributable to linkage disequilibrium. MTHFR 677CT/1298CC and 677TT/1298CC genotypes (P<.05) were not observed in either group. CONCLUSIONS: The absence of MTHFR 677CT/1298CC and 677TT/1298CC genotypes in both groups suggests that certain MTHFR genotypes may carry a selective advantage. Our discovery of a substantial number of MTHFR mutations in cis configuration suggests that any MTHFR allele linkage disequilibrium present is incomplete.     

Methylenetetrahydrofolate reductase polymorphism, plasma homocysteine and age

BACKGROUND: Elevated fasting levels of total homocysteine are now accepted as an independent risk factor for the development of arteriosclerotic vascular diseases. A polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR), caused by the C677T point mutation, leads to increased thermolability of the enzyme, with reduced enzyme activity. We studied the frequency of this mutation in different groups of the Swiss adult population. PATIENTS AND METHODS: DNA from 361 subjects was screened for the thermolabile MTHFR variant with PCR. Included were healthy subjects without vascular disease (n = 118), older healthy subjects (n = 106), patients with coronary artery disease (CAD, n = 75), and patients with peripheral arterial occlusive disease (PAOD, n = 63). RESULTS: In the different groups studied, homozygosity for the mutation ranged from 4.8 to 16.2%, with a frequency of 16.2% in the healthy cohort. The allele frequencies of the thermolabile allele were 38.5 and 27.3 in young and old controls, and 37.3 and 33.3 in CAD and PAOD patients. In the healthy younger subjects the mutant allele was 1.4 times more frequent compared to the older subjects (P = 0.01). No difference in either MTHFR genotype distribution (P = 0.33) or allele frequencies (P = 0.48) between patients and controls was found. Except for the PAOD group with elevated tHcy levels for the +/+ carriers compared to the other genotypes, no statistically significant difference was found comparing homocysteine levels with genotype. CONCLUSION: This study shows no link between the mutation and the occurrence of vascular disease but we found evidence pointing to a correlation between the mutation and longevity in our population.     

桂东南地区2型糖尿病肾病与 MTHFR 基因 C677T 多态性的相关性

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（DN）的关系。方法应用聚合酶链反应-限制性片段长度多态性的方法,检测桂东南地区2型糖尿病患者163例 MTHFR 基因 C677T 多态性,其中 DN 82例、单纯糖尿病（DM）81例和健康对照组（CON）77例。同时检测血清同型半胱氨酸（Hcy）水平,并比较各组间 MTHFR 基因型频率、等位基因频率和 Hcy 水平。结果DN 组 MTHFR 基因纯合基因型（TT）、杂合基因型（CT）及 T 等位基因频率（分别为4．9％、37．8％和23．8％）均明显高于 DM 组（分别为2．5％、28．4％和16．7％）和 CON 组（分别为0．0％、29．8％和14．9％）,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 DM 组和 CON 组之间的分布差异无统计学意义（P ＞0．05）。单因素 Logistic 回归分析结果显示,MTHFR 基因型 C677T 多态性与 DN 的发生密切相关（OR 值及其95％CI 分别为1．660、1．038和2．655）。携带T 等位基因患者血中 Hcy 水平显著高于未携带 T 等位基因患者,差异有统计学意义（P ＜0．01）。结论MTHFR 基因 C677T 多态性与桂东南地区2型糖尿病患者 DN 相关,MTHFR T 等位基因可能是该地区 DN 的易感基因。     

四氢叶酸还原酶基因多态性与不稳定型心绞痛关系的研究

目的 探讨四氢叶酸还原酶(MTHFR)基因C677T变异与中国人群不稳定型心绞痛(UA)的关系.方法 随机收集90例UA患者(UA组),并收集与之年龄、性别相匹配的90例体检健康对照人群(对照组),采用聚合酶链反应-限制性片段多态性(PCR-RFLP)方法 进行MTHFR基因C677T变异的分析.观察不稳定型心绞痛与MTHFR基因C677T多态性的关系.结果 UA组MTHFR基因677TT纯合子为9例,C677T杂合子为21例,突变率33.33%;对照组MTHFR基因677TT纯合子为3例,C677T杂合子为12例,突变率16.67%;结果 显示2组MTHFR基因C677T变异差别有统计学意义(P<0.05).结论 MTHFR基因C677T变异与中国人群不稳定型心绞痛的发生相关.     

Genotyping of the MTHFR gene polymorphism, C677T in patients with leukemia by melting curve analysis.

BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR) plays a critical role in folate metabolism and displays common genetic polymorphisms affecting the enzyme activity. The MTHFR genetic polymorphisms have been associated with a decrease in the risk of developing the lymphoid but not myeloid form of pediatric and adult leukemias. AIM: In this study we describe the genotyping of the MTHFR C677T polymorphism by melting curve analysis with the LightCycler in a case-controlled study of patients with acute lymphocytic leukemia (ALL), myelogenous leukemia (AML), and chronic myelogenous leukemia (CML), and assess the effect of this common polymorphism on the leukemia risk in adult patients in Turkey. METHODS: DNA from peripheral blood lymphocytes was used for genotyping in the LightCycler PCR by melting curve analysis. The risk of leukemia associated with the MTHFR polymorphism was evaluated by comparing the genotype frequencies between the control and patient groups. RESULTS: The frequency of the homozygote variant genotype (677TT) was lower than that in healthy individuals in all three leukemia groups. The 677TT genotype did not appear to have a protective effect in patients with ALL (Odds ratio [OR] = 0.78 with a 95% confidence interval [CI] = 0.24-2.59), compared with healthy controls. The difference was higher (4.3-fold) in patients with AML, but still non-significant (OR = 0.23 with a 95% CI = 0.03-1.83). In patients with CML, the frequencies of both heterozygous (677CT) and homozygote variant genotypes were lower (OR = 0.72 and 0.66, respectively). CONCLUSIONS: Our results suggest that the MTHFR C677T polymorphism displays a similar distribution pattern in lymphoid and myeloid leukemias and that the frequency of the homozygote variant genotype (677TT) is lower in all leukemia types.     

Thrombophilic risk factors in patients with severe carotid atherosclerosis.

Carotid stenosis and atrial fibrillation are the strongest risk factors for ischemic stroke. Ongoing prevention efforts include the identification of novel factors that increase the risk for carotid atherosclerosis. The aim of this study was to determine the thrombophilic risk profile of patients with severe carotid stenosis by evaluating a number of genetic and metabolic risk factors [factor (F)II G20210A, factor V Leiden, MTHFR C677T polymorphisms, anticardiolipin antibodies (aCL), lipoprotein(a) (Lp(a)), and homocysteine (Hcy)]. The study population consisted of 615 patients [(410 M/205 F; median age 73 (26-94) years] with severe (> 70%) carotid stenosis, and 615 apparently healthy subjects [(410 M/205 F; age 73 (31-92) years]. On multivariate analysis, independent risk factors were elevated Hcy [odds ratio (OR) 7.6, 95% confidence interval (CI) 4.8, 11.8] and Lp(a) levels (OR 2.9, 95% CI 2.1, 3.9), the presence of aCL (OR 5.7, 95% CI 3.1, 10.4) and heterozygosity for FII G20210A polymorphism (OR 2.8, 95% CI 1.3, 5.9). In the subgroup of women, independent risk factors for severe carotid atherosclerosis were: high levels of Hcy and Lp(a) and the presence of aCL, whereas hyperhomocysteinemia, elevated Lp(a) levels, aCL, FII G20210A and MTHFR 677TT polymorphisms remained independent risk factors in the subgroup of men. The results of the present study demonstrate that the prevalence of the thrombophilic risk factors is increased in patients with severe carotid atherosclerosis.     

SNP基因芯片方法的建立及在MTHFR多态性检测中的初步应用

目的 建立单核苷酸多态性（SNP）的基因芯片检测法,并初步应用于结直肠癌患者MTHFR基因位点C677T的多态性检测,分析其位点突变与致病性的关系.方法 采用醛基修饰玻璃基片,阵列检测亚甲基四氢叶酸还原酶（MTHFR）C677T基因型,生物素标记显色.应用该芯片检测78例结直肠癌患者及40例健康对照组MTHFR基因C677T多态性,并分析MTHFR基因多态性与结直肠癌的相关性.结果 建立检测MTHFR基因SNP的基因芯片.采用基因芯片法检测病例组中MTHFR基因的C677T位点CC、CT、TT基因型分布频率分别为38.5%、53.8%、7.7%,健康对照组中C677T位点CC、CT、TT基因型分布频率分别为35.0%、62.5%、2.5%.结论 成功建立检测SNP的基因芯片法.MTHFR基因位点C677T的基因多态性与结肠癌易感性无明显关系.     

MTHFR C677 T gene polymorphism in lymphoproliferative diseases

Methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, has been implicated in cancer risk. In the present study we used a melting curve analysis to investigate the association of the common MTHFR C677 T polymorphism with lymphoproliferative diseases. Patients (n=117) were compared with age- and sex-matched control subjects (n=154). Our results indicate that the 677 T variant occurred less frequently in patients (26%) than in the control group (33.7%; P=0.05). Investigation of the variant allele (677 T) frequency in the subgroups with Hodgkin's lymphoma (HL) and B-cell neoplasms (BCNs) revealed that this difference was a result of the significantly lower distribution of the variant allele in patients with HL (20.5%; P=0.01). This was accompanied by a significantly higher frequency of the homozygote normal genotype (677CC) among the patients with HL. In patients with BCNs the distribution of the variant allele (30.3%) was comparable to that in the control group (P=0.47). However, the difference between HL (20.5%) and BCNs (30.3%) did not reach statistical significance (P=0.09). Our results suggest that the distribution of the C677 T polymorphism may vary among lymphoproliferative diseases.     

Relationship between thiolactonase activity and hyperhomocysteinemia according to MTHFR gene polymorphism in Tunisian Beh?et's disease patients.

BACKGROUND: Beh?et's disease (BD) is a multisystemic immuno-inflammatory disorder. Inflammatory processes may cause lipid peroxidation, alteration of lipid profile and increase the risk of atherosclerosis. The aim of this study was to evaluate the association between thiolactonase (HTLase) activity and plasma homocysteine levels (tHcy) in a BD population and to investigate their association with methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype. METHOD: A total of 35 BD patients were compared to 39 healthy volunteers. RESULTS: Significantly higher tHcy levels associated with lower HTLase activities were found in BD patients as compared to healthy controls (p<0.001). These patients also exhibited lower values of triglycerides and high-density lipoprotein cholesterol (HDL-C). Homozygosity for the T allele of the MTHFR gene was more frequent in BD patients (14.3% vs. 7.7%). It was associated with significantly higher tHcy levels (16.9 micromol/L for n=17 vs. 13.1 micromol/L for n=18; p<0.05) and markedly lower HTLase activity (362.6+/-156.7 U/L vs. 414.2+/-180.2 U/L) for the (TT+CT) and CC genotypes, respectively. Moreover, HDL-C levels were inversely correlated with tHcy (r=-0.5; p=0.004) but positively associated with HTLase activity (r=0.374; p=0.038). These correlations were also present in several clinical manifestations, such as ocular, neurological involvement or thrombosis. CONCLUSIONS: Homozygosity of the T allele of the MTHFR gene is prevalent in BD patients. High levels of tHcy associated with low HTLase activities may be one of the causes leading to thrombosis in BD patients.     

基因芯片法分析MTHFR基因C677T还原酶位点多态性与原因不明不良孕产的关系

目的探讨5,10-亚甲基四氢叶酸还原酶(MTHFR)基因C677T位点多态性与原因不明不良孕产的关系。方法选取2014年6月至2016年5月在新乡市第一人民医院不孕不育科、妇产科就诊的原因不明不良孕产≥2次320例孕妇作为病例组,388例无流产史健康经产妇作为对照组。采用基因芯片法分析两组人群MTHFR基因C677T位点多态性;比较组间基因型、等位基因频率分布的差异,分析原因不明不良孕产与MTHFR C677T位点多态性的关系。结果 MTHFR C677T基因型C/C频率分布病例组和对照组比较差异有统计学意义(P0.05、OR=0.284);基因型C/T频率分布两组间比较差异无统计学意义(P=0.400、OR=1.140);基因型T/T频率分布两组间比较差异有统计学意义(P0.05、OR=7.672);等位基因C、T频率分布两组间比较差异有统计学意义(P0.05、OR=0.304)。结论 MTHFR C677T基因型T/T的高表达可能是育龄女性妇女原因不明不良孕产的危险因素。     

The methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and cancer risk: the Croatian case-control study

OBJECTIVES: Methylation abnormalities appear to be important for the pathogenesis of many cancer types. Since methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the methylation process catalyzing reduction of 5,10-methylenetetrahydrofolate to 5-methyl-tetrahydrofolate, C677T polymorphism, which decreases enzyme activity, may be associated with cancer susceptibility. The aim of this work was to investigate the distribution of MTHFR C677T polymorphism between various types of cancer and cancer-free controls and to assess if there is a difference in frequency. MATERIALS AND METHODS: 269 Cancer cases (95 prostate cancer, PC; 81 head and neck, HN; and 93 breast cancers, BC) and 102 healthy controls, free of cancer, were genotyped for C677T MTHFR polymorphism using the PCR-RFLP method. RESULTS: There was no overall difference in C677T genotype distribution between total cancer cohort and controls (p=0.064). However, a significant difference and protective OR was found for the C/T genotype (OR=0.574, 95% CI=0.352-0.935). In a comparison of different cancer types and respective controls, genotype frequencies were significantly different between head and neck carcinoma and controls (p=0.004), again with protective role of C/T genotype (OR=0.356, 95% CI=0.189-0.671). Moderate overrepresentation of C/T was found in respective male controls when compared with prostate cancer patients (p value was 0.074 for C/T vs. C/C comparison). The OR for heterozygous C/T genotype in prostate cancer group was 0.404, pointing to its putative protective role. Genotype and allelic frequencies did not differ significantly between 93 breast cancer patients and their 65 age-matched female controls. CONCLUSION: Our data indicate that the C677T MTHFR polymorphism does not significantly contribute to the inherited genetic susceptibility to breast and prostate cancer, while we show some evidence for possible genetic contribution of this polymorphism to the development of head and neck carcinoma.     

Hyperhomocysteinemia and elevated ox-LDL in Tunisian type 2 diabetic patients: role of genetic and dietary factors

INTRODUCTION: Total plasma homocysteine (tHcy) is an emerging risk factor for the development of atherosclerosis. However, its relationship with diabetes is still unclear. OBJECTIVES: We evaluated the association between tHcy levels and methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype in a type 2 diabetes mellitus (DM) population and their relationship with oxidized LDL (ox-LDL) according to dietary habits and vascular complications. DESIGN AND METHODS: Eighty-six DM patients were compared to 120 healthy volunteers. RESULTS: Associated higher tHcy levels and significantly higher ox-LDL levels (p<0.001) were found in DM patients compared to healthy subjects. Homozygosity for the T allele of MTHFR was more frequent in diabetics than in healthy subjects (12.8% vs. 7.2%) and it was associated with higher tHcy levels. Moreover, this elevated level was associated with significantly higher ox-LDL levels in DM patients with hypertension (p<0.05). Improving folate and vitamin C intakes could have beneficial effects on lowering the tHcy and ox-LDL levels. CONCLUSIONS: The interplay of genetic and dietary factors modulates the effect of homocysteine on cardiovascular risk factors.     

Polymorphism of apoprotein E (APOE), methylenetetrahydrofolate reductase (MTHFR) and paraoxonase (PON1) genes in patients with cerebrovascular disease.

Although controversial, data on the genetic polymorphism of apoprotein E (APOE), methylenetetrahydrofolate (MTHFR) and paraoxonase (PON1) genes implicate their role in the development of cerebrovascular disease. The aim of this study was to assess the association of polymorphism of APOE, MTHFR and PON1 genes in 56 stroke and 36 carotid stenosis patients, and in 124 control subjects by PCR-restriction fragment length polymorphism analysis. In the stroke group a significantly different MTHFR genotype distribution (p=0.004, odds ratio for T/T of 17.571), but no significant difference in APOE and PON1 allele and genotype distribution compared to the control was found. The carotid stenosis group exhibited a significantly different APOE allele and genotype distribution (p=0.023, odds ratio APOEepsilon3epsilon4 of 4.24), but no significant difference in the MTHFR and PON1 allele and genotype distribution from the control group. The preliminary results obtained in this study revealed an association of the MTHFR and APOE gene polymorphism with cerebrovascular disease, suggesting a significant risk for stroke in subjects who are homozygous for the T allele and for carotid stenosis in subjects having APOEepsilon3epsilon4 genotype. Additional studies in larger patient groups are needed to confirm these observations.     

脑梗死患者同型半胱氨酸、5,10-亚甲基四氢叶酸还原酶基因多态性与颈动脉粥样硬化的相关性

目的探讨脑梗死患者急性期血清同型半胱氨酸（homocysteine,Hcy）、5,10-亚甲基四氢叶酸还原酶（methylenetetrahydrofolate,MTHFR）基因多态性与颈动脉粥样硬化之间的相关性。方法研究共纳入90例急性脑梗死患者和40例正常人,用循环酶法测定血清Hcy水平;用彩色多普勒超声检查颈动脉颅外段;采用聚合酶链反应-限制性内切酶片段长度多态性方法检测MTHFR基因型多态性。结果病例组颈总动脉（CCA）及颈内动脉（ICA）内中膜厚度（IMT）较对照组显著增厚（1.07±0.30）mm vs（0.87±0.33）mm,（1.00±0.31）mm vs（0.65±0.16）mm（均P〈0.01）。病例组较对照组颈动脉斑块发生率显著增高（74.4%vs 45.0%,P〈0.01）。病例组中不稳定斑块占所有斑块的比例较对照组中有增高的趋势,但差异无统计学意义（P〉0.05）。C/C、C/T、及T/T基因型人群血清Hcy水平分别为12.95（9.50~16.58）μoml/L,19.08（12.05~25.63）μoml/L,28.32（18.00~36.80）μoml/L,呈递增趋势,各组间差异有统计学意义（均P〈0.05）。Logistic回归分析显示在校正了传统的危险因素后,Hcy仍然是颈动脉粥样硬化的独立危险因素（P〈0.01）;MTHFRC677T基因多态性未进入回归方程。结论血清Hcy升高是脑梗死独立危险因素;MTHFRC677T基因多态性与颈动脉粥样硬化无相关性。     

MTHFR基因多态性和同型半胱氨酸在冠心病脑梗死和糖尿病中的分析

目的探讨冠心病、脑梗死、糖尿病患者亚甲基四氢叶酸还原酶（MTHFR）和血浆同型半胱氨酸（Hcy）的关系,对三个病种的MTHFR基因型进行分析。方法收集120例冠心病,214例脑梗死,112例糖尿病患者及98例健康体检者标本,采用聚合酶链式反应-限制性片段长度多态性（PCR-RFLP）技术检测MTHFRC677T基因,采用酶循环法检测血浆Hcy,比较四组MTHFRC677T基因多态性及血浆Hcy的差异。结果（1）MTHFR基因型在冠心病,脑梗死和糖尿病组与健康对照组间差异无统计学意义（P＝0．670）;（2）MTHFR基因频率在冠心病,脑梗死和糖尿病组与健康对照组间差异无统计学意义（P＝0．721）;（3）冠心病组和脑梗死组的MTHFR基因TT型患者的Hcy水平远远高于CC型和CT型患者（F＝6．212,P＝0．003;F＝44． 362,P＝0．000）。结论不同病种间MTHFR基因型和基因频率差异无统计学意义,但冠心病组和脑梗死组MTHFR基因TT型患者Hcy水平则远远高于CC型和CT型患者,差异有统计学意义。     

Patterns of co-occurrence of three single nucleotide polymorphisms of the 5,10-methylenetetrahydrofolate reductase gene in kidney transplant recipients

BACKGROUND: Recently, a new mutation of the 5,10-methylenetetrahydrofolate reductase (MTHFR) encoding gene was first described (1793G > A). Only few reports have studied the prevalence of this polymorphism, especially in combination with other MTHFR mutations (677C > T, 1298A > C). METHODS: We cross-sectionally identified the novel MTHFR 1793G > A polymorphism in 730 kidney transplant recipients. MTHFR 677C > T and 1298A > C were also assessed and the frequency of each was described individually as well as in cross-tabulation with the other MTHFR genotypes. The expected number of patients for each MTHFR genotype combination was calculated and contrasted with the observed numbers. Fisher's exact test was used for statistical inference. RESULTS: The allelic frequency of MTHFR 1793G > A was 0.052. Seventy-two patients (9.9%) were heterozygous and two patients (0.3%) were homozygous. From the cross-tabulations, we identified 53 patients (expected: 33.6) with the MTHFR 1298AC/1793GA genotype and 17 patients (expected: 6.7) with the MTHFR 1298CC/1793GA genotype. Furthermore, we found two patients with double homozygosity for MTHFR 1793G > A and MTHFR 1298A > C (MTHFR 1793AA/1298CC genotype). The frequencies of these genotype combinations were substantially larger than could be expected (P < 0.001). CONCLUSIONS: These findings suggest a selection or survival advantage for individuals with combined MTHFR 1793G > A and MTHFR 1298A > C genotypes, possibly owing to a mutually stabilizing effect on MTHFR enzyme activity.     

Influence of MTHFR genotype on contingent negative variation and MRI abnormalities in migraine

BACKGROUND: The MTHFR C677T genotype has been associated with increased risk of migraine, particularly of migraine with aura (MA) in selected clinical samples and with elevated homocysteine. The hyper-homocysteinemia may favor the vascular and neuronal mechanism underlying migraine, and the risk of stroke. OBJECTIVE: The first aim of the present study was to examine the Contingent Negative Variation (CNV) amplitude and habituation pattern in a migraine sample versus non-migraine subjects, at the light of the MTHFR genotype, according to an unrelated and clinical based case-control panel. The second aim was to compare the frequency of Magnetic Resonance Imaging (MRI) subclinical brain lesions across the different C677 genotypes in the same migraine sample, selected for the young age and the absence of any cardiovascular risk factor. METHODS: One hundred and five 18-45 year old out-patients, 90 affected by migraine without aura (MO) and 15 by MA, and 97 non-migraine healthy subjects, age and sex matched, were selected for the genetic analysis. All subjects had a common ethnic origin from Puglia. Sixty-four migraine subjects and 33 control subjects were submitted to the recording of the CNV. All migraine subjects underwent the MRI evaluation. RESULTS: The frequency of homozygosis was 14.33% in normal subjects, versus 25.7% in MA + MO group (chi2-test: 10.80 P= .001). The frequency of homozygosis in MO patients, was 25.5% (MA versus N: chi2-test: 9 P= .003), in MA group it was 26.6%. Considering the MTHFR genotype in migraine patients and controls, the C677TT subjects exhibited a reduced habituation index of the early CNV (iCNV), in respect with both C677TC and C677CC; in the migraine group, there was a significant decrease of CNV habituation in patients with homozygosis and a positive correlation between the habituation index values and the homocysteine levels. Nineteen migraine patients exhibited subclinical brain lesions (18.05%): patients with C677T homozygosis did not exhibit a higher risk for MRI abnormalities. CONCLUSIONS: This unrelated and clinical based case-control study showed that genetically induced hyper-homocysteinemia may favor the neuronal factors predisposing to migraine, while it does not influence the presence of subclinical vascular brain lesions probably linked with increased risk of stroke.     

潍坊市汉族女性叶酸代谢关键酶基因多态性分布研究

目的:针对潍坊市汉族女性开展分子流行病学调查,研究叶酸代谢关键酶MTHFR和MTRR的基因多态性分布。方法:以孕期保健的670例汉族健康女性为研究对象,采集口腔黏膜上皮脱落细胞,抽提基因组DNA,使用荧光定量PCR方法检测MTHFR C677T、A1298C和MTRR A66G基因多态性,进行统计分析。结果:1)入组对象的基因多态性分布符合遗传平衡。2)汉族女性MTHFR 677CC、CT、TT的基因型频率分别为13.73%、47.91%、38.36%,C、T等位基因频率分别为37.7%、62.3%;MTHFR 1298AA、AC、CC的基因型频率分别为75.52%、23.28%、1.19%,A、C等位基因频率分别为87.2%、12.8%;MTRR 66AA、AG、GG的基因型频率分别为54.63%、40.44%、4.93%,A、G等位基因频率分别为74.9%、25.1%。3)汉族女性MTHFR C677T和A1298C两位点连锁有7种组合,频率最高的是TT/AA(38.21%),没有CT/CC和TT/CC组合。两位点间存在完全连锁不平衡(D'=0.987,r2=0.237)。结论:获取潍坊市汉族女性MTHFR和MTRR基因多态性的群体遗传学特征。     

探讨MTHFR基因多态性与新疆地区人群唇腭裂发病的关系

目的 探讨亚甲基四氢叶酸还原酶（MTHFR）基因C677T和A1298C多态性与新疆地区部分人群非综合征性唇腭裂（NSCL/P）发病的关系.方法 采用病例对照设计,试验组为新疆地区NSCL/P患儿44例（维吾尔族12例,汉族32例）;对照组为非唇腭裂患儿62例（维吾尔族26例,汉族36例）.应用聚合酶链式反应-限制性片段长度多态性方法（PCR-RFLP）对MTHFR基因C677T和A1298C进行多态性检测.结果 新疆地区汉族NSCL/P的MTHFR C677T和A1298C位点基因型及等位基因频数与对照组差异无统计学意义（x2=0.07,P ＞0.05;X2 =0.30,P＞0.05）;维吾尔族NSCL/P的MTHFR C677T位点基因型及等位基因频数与对照组差异无统计学意义（X2=0.12,P ＞0.05）,而MTHFR A1298C位点基因型及等位基因频数与对照组比较其差异有统计学意义（X2=8.90,P ＜0.01）.结论 新疆地区汉族MTHFR基因C677T和A1298C位点多态性可能与NSCL/P的发生无关;维吾尔族MTHFR基因C677T位点多态性与NSCL/P的发生可能无关,而A1298C位点多态性与NSCL/P的发生相关,可能是NSCL/P发病的易感因素.