Genetic thrombophilic defects (Factor V Leiden, prothrombin G20210A, MTHFR C677T) in women with recurrent fetal loss

Maternal thrombophilia (inherited and acquired) has recently been identified as a major cause of thrombembolism, but it may also contribute to adverse pregnancy outcomes and recurrent pregnancy loss. To determine the association of specific inherited thrombophilias and recurrent fetal loss (RFL), three gene mutations (Factor V Leiden, prothrombin G20210A, MTHFR C677T) were investigated. The prevalence of the thrombophilic markers was compared in 156 women with history of fetal loss in different trimester of pregnancy and 80 matched controls. At least one thrombophilic defect was found in 28.2% of total study group women compared with 16.2% in controls (p=0.06; OR-2.02) and in 50% of women with RFL in third trimester (p=0.008; OR-5.15). Factor V Leiden was more common in the group of women with fetal loss in third trimester (37.5%) compared to the controls (6.2%) (p=0.002; OR-9.0). Presence of FVL was associated with a significant increased risk for RFL in second and third trimester (OR-6.25; P<0.001) and significant protection for RFL in first trimester (OR-0.16; P<0.001). Mutation prothrombin G20210A or MTHFR C677T was more common in group of women with fetal loss in first trimester compared to the controls (28.3% vs. 11.2% respectively; p=0.009; OR-3.11). The presence of either of these mutations was associated with no significant increased risk for RFL in first trimester (OR-2.5). Genetic thrombophilic defects are common in women with RFL and are associated with late fetal loss. This association is manifest by FVL rather than total number of defects involved.     

MTHFR C677T polymorphism and recurrent early pregnancy loss risk in north Indian population

Recurrent early pregnancy loss (REPL) is a multifactorial disorder as both genetic and environmental factors contribute to the development of disease. Folate metabolism is an important mechanism to ensure proper fetal growth. Hyperhomocysteinemia leads to a number of disorders and REPL is one of them. In a case-control study DNA from 106 cases with the history of 3 or more REPL and 140 healthy fertile controls with successful pregnancy outcomes were genotyped for C677T single-nucleotide polymorphism (SNP) of the MTHFR (methylenetetrahydrofolate reductase) gene through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), which was further confirmed by sequencing. Allele frequencies of REPL cases were compared with healthy controls and a statistically significant association was found between REPL and the mutant T allele (χ2 = 8.786, odds ratio [OR] = 2.20, 95% confidence interval [CI] = 1.323-3.9658, P = .003). The genotype frequencies of SNP C677T also differ significantly between these 2 groups (χ2 = 8.237, P = .016). The OR for heterozygous CT in the REPL versus controls is 1.9591 (95% CI = 1.0285-3.7318, P = .04). The OR for TT homozygous is 6.3009 (95% CI = 1.2065, P = .02). Combined odds ratio of CT and TT against the control has been calculated as 2.2194 (95% CI = 1.2029-4.0952, P = .02) which is also significant. Thus the present study clearly indicates that homozygosity and heterozygosity for the MTHFR C677T polymorphism confer a 6.3009- and 1.9591-fold increased risk of idiopathic REPL, respectively.     

MTHFR C677T polymorphism associates with unexplained infertile male factors

PURPOSE: To determine whether 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) genotype is associated with male infertility. METHODS: Analysis of cytogenetic, Y chromosomal microdeletion assay (Yq), and the C677T and A1298C polymorphisms of the MTHFR gene by pyrosequencing and PCR-Restriction Fragment Length Polymorphism (RFLP) method. SAS 8.1 assessed the statistical risk of MTHFR genotype. RESULTS: The homozygous (T/T) C677T polymorphism of the MTHFR gene was present at a statistically high significance in unexplained infertile men with normal karyotype, instead at no significance in explained infertile men with chromosomal abnormality or Y chromosome deletion. There was no statistically significance of A1298C variation in infertile males. CONCLUSIONS: The MTHFR 677TT genotype may be a genetic risk factor for male infertility, especially with severe OAT and non-obstructive azoospermia in unexplained infertile males.     

Prothrombin 20210 G-->A, MTHFR C677T mutations in women with venous thromboembolism associated with pregnancy

Over 50 unselected women with maternal venous thromboembolism were screened for the prothrombin 20210 G→A and MTHFR C677T mutations, in addition to screening for other thrombophilias. The prevalence of thrombophilia in these women was compared with its prevalence in the general population in our area. The prothrombin (OR 4.4; 95% CI 1.2-16) and factor V Leiden (OR 4.5; 95% CI 2.1-14.5) mutations were more common in our patients, compared with the general population, whereas women homozygous for the C677T mutation in the methylene tetrahydrofolate reductase gene (OR 0.45; 95% CI 0.13-1.58) were not. It is recommended that women with a personal or strong family history of venous thromboembolism should be screened for the prothrombin mutation either before or early in pregnancy, in addition to screening for other thrombophilias. Screening for the MTHFR mutation does not appear to identify women at increased risk of maternal venous thrombosis.     

Inherited thrombophilia screening in Greek women with recurrent fetal loss

OBJECTIVE: The present study was designed to determine the prevalence of factor V Leiden (FVL), prothrombin gene G20210A (PTG) and methylenetetrahydrofolate reductase (MTHFR C677T) mutations in women from South-Western Greece with recurrent fetal loss (RFL) and negative personal thromboembolic history. MATERIALS AND METHODS: 212 women with RFL and 181 women with at least two pregnancies with normal outcome and no history of pregnancy loss were investigated for the commonest thrombophilic mutations (FVL, PTG, MTHFR C677T). Comparisons between groups were performed by Pearson's chi-square test and odd ratios were calculated. RESULTS: An abnormal genotype was detected in 49 women of the study group (23.1%) and in 41 women of the control group (22.6%). CONCLUSION: Inherited thrombophilia screening is not indicated as an initial approach in Greek women with RFL and negative personal thromboembolic history.     

MTHFR C677T Polymorphism is Not Associated with Placental Abruption or Preeclampsia in Finnish Women

Objective: The aim of our study was to examine genetic variability in the gene encoding methylenetetrahydrofolate reductase (MTHFR) and individual susceptibility to the placental abruption or preeclampsia. Methods: 362 women (133 with preeclampsia, 117 with placental abruption, and 112 healthy controls) were genotyped for C677T polymorphism in the MTHFR gene. Results: Similar genotype distributions were observed in the frequencies of C/C homozygotes (58.6%, 64.1%, and 57.1% for the three groups, respectively) and mutant homozygotes T/T (9.0%, 5.1% and 5.4%). No significant differences were detected in T allele frequencies (25.2%, 20.5%, and 24.1% for the three groups, respectively). Conclusions: MTHFR C677T polymorphism does not have a major role in the development of preeclampsia or placental abruption in the Finnish population.     

Polymorphism for mutation of cytosine to thymine at location 677 in the methylenetetrahydrofolate reductase gene is associated with recurrent early fetal loss.

OBJECTIVE: This study was undertaken to determine whether a cytosine to thymine mutation at nucleotide 677 in the gene encoding for methylenetetrahydrofolate reductase is associated with particular subtypes of recurrent unexplained spontaneous abortion. STUDY DESIGN: The prevalences of cytosine to thymine mutation at nucleotide 677 in the gene encoding for methylenetetrahydrofolate reductase among 41 patients with recurrent unexplained spontaneous abortions and among 18 healthy control subjects were determined with polymerase chain reaction. RESULTS: Homozygosity and heterozygosity for the cytosine to thymine mutation at nucleotide 677 in the gene encoding for methylenetetrahydrofolate reductase were observed at nonsignificantly different rates among patients and control subjects (9% and 48% versus 22% and 38%, respectively, P <.95). Among patients with recurrent unexplained spontaneous abortions both homozygosity and heterozygosity were associated with significantly increased prevalence of recurrent early fetal loss rather than with repeated anembryonic gestations (P <.0001). CONCLUSION: The observation that polymorphism for the cytosine to thymine mutation at nucleotide 677 in the gene encoding for methylenetetrahydrofolate reductase is associated with repeated early fetal losses rather than with anembryonic gestations strengthens the argument for the role of hypercoagulability and abnormal uteroplacental vasculature in recurrent spontaneous abortion.     

MTHFR基因677C/T多态性对精子密度的影响

目的:探讨MTHFR基因677C/T的多态性对人类精子密度的影响。方法:应用PCR和限制性片段长度多态(RFLP)分析的方法在280例精子密度正常的男性个体中,对MTHFR基因677C/T位点的基因型分布进行调查,并评估不同基因型个体的平均精子密度。结果:在280例男性中,基因型CC、CT和TT的个体数分别为145、104和31,其平均精子密度分别为70.8±33.9×106/ml、67.6±31.2×106/ml和60.2±24.5×106/ml;基因型CC的精子密度显著高于TT型(P<0.05)。结论:MTHFR基因677C/T多态性可能对精子密度产生影响,降低精子密度。     

Methylenetetrahydrofolate C677T polymorphism and pre-eclamptic Egyptian women

Thrombosis of the maternal spiral arteries can be one of the causative events in pre-eclampsia disease, it has been suggested that the C677T polymorphism may also play a role in the pathogenesis of pre-eclampsia.Aims of the workTo investigate the frequency of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in Egyptian pregnant women’s with pre eclampsia, and compare with the control group.Type of studyA prospective comparative study among two groups of subjects: 44 preeclamptic women and 44 women with normal pregnancies from November 2008 to April 2010, at Suez Canal University, Faculty of Medicine, Obstetrics and Gynecology Department, DNA was amplified by polymerase chain reaction with sequences specific primers (SSP-PCR). DNA purification capture column kit (Gentra system, USA). Digestion was performed by restrictasc Hinf1 (Fermentas), visualization of genomic DNA by minigel electrophoresis primer sequences. The gels were then photographed under UV light (320 nm) and scored for the presence or absence of an allele specific band.ResultsThe study group had a significantly higher frequency of the homozygous mutated TT allele (34.1% vs. 0.0%, P < 0.0001) and T Allele genotype of C677T polymorphisms compared to controls, (56.8% vs. 31.8%) in both groups respectively and significant OR (46.76).The control group had a higher frequency of both the heterozygous mutated CT and homozygous CC genotypes of C677T polymorphism than the other groups (P < 0.0004)ConclusionC677T polymorphism of MTHFR gene was found to be associated with the development of pre-eclampsia. Mutant T allele and TT genotypes of C677T may be considered genetic risk factors for the development of pre-eclampsia among Egyptian pregnant women.     

亚甲基四氢叶酸还原酶677C→T突变与不明原因反复流产相关性研究

目的　探讨亚甲基四氢叶酸还原酶 (MTHFR) 6 77C→T突变与不明原因反复流产之间的相关性。方法　采用聚合酶链反应———限制性片段长度多态性 (PCR RFPL)的方法 ,通过病例对照研究 ,对 6 2例有两次及两次以上不明原因流产史的病例 (按不同流产时间分为早期流产组和晚期流产组 ) ,与 119例健康者对照进行MTHFR的检测。结果　早期流产组中MTHFR不同突变型的分布与对照组有显著差异 (χ2 =8 15 4,P <0 0 5 ) ,纯合突变型频率 (11/ 32 ,34 37% )明显高于对照组 (2 3/ 119,19 33% ) [OR =2 186 ,95 %CI(0 92 5 -5 16 5 ) ],杂合突变型频率 (16 / 32 ,5 0 0 0 % )与对照组相比 (5 3/ 119,44 5 4% )未发现有显著差异 [OR =1 2 45 ,95 %CI (0 5 70 - 2 72 0 ) ];T等位基因频率 (0 5 937)与对照组 (0 415 9)相比有显著性差异 (χ2 =13 89,P <0 0 0 5 )。而晚期流产组MTHFR不同突变型的分布与对照组无显著差异 (χ2 =1 490 ,P >0 0 5 )。结论　MTH FR 6 77C→T纯合突变与早期流产有明确的相关性     

亚甲基四氢叶酸还原酶基因677位多态性、高同型半胱氨酸血症与复发性流产

目的:探讨亚甲基四氢叶酸还原酶基因(MTHFR)多态性(C677T)与高同型半胱氨酸(Hcy)血症以及复发性流产之间的关系。方法:采用前瞻性病例对照研究方法,收集71例复发性自然流产患者为病例组,另征集同期58例有正常妊娠史者为对照组,利用PCR-RFLP方法研究MTHFR基因多态性(C677T);同时应用酶法测定血清同型半胱氨酸水平;并随访病例组的妊娠结局。结果:①MTHFR基因677位点的3种基因型在病例组和对照组分布分别为CC:14.1%vs 43.1%、CT:49.3%vs 25.9%、TT:36.6%vs 31.0%,组间比较有极显著统计学差异(χ2=14.7,df=2,P=0.001);其中CC基因型在病例组显著降低(P=0.000,OR=0.216,95%CI:0.093-0.505);T等位基因分布在病例组显著升高(61.3%vs 38.7%,P=0.006)。②129例研究对象中TT基因型血同型半胱氨酸水平显著升高(P=0.000):TT为19.0±9.5 nmol/L、CC为13.1±6.2 nmol/L、CT为11.7±4.0 nmol/L,病例组和对照组高Hcy水平组间无统计学差异(P>0.05)。③病例组中有38.0%(27/71)为高Hcy血症,叶酸治疗有效。结论:MTHFR基因多态性(C677T)与复发性流产有关;MTHFR基因TT型与高Hcy血症有关;叶酸可用于治疗高Hcy血症且有助于改善下次妊娠结局。     

Mutations in the factor V,prothrombin and MTHFR genes are not risk factors for recurrent fetal loss

Objective: Recurrent fetal loss, defined as the occurrence of three or more consecutive spontaneous abortions regardless of previous live birth, is a condition that affects about 2% of all reproductive-aged women. The role of gene mutations in recurrent pregnancy loss is not fully understood. The present research examined the relationship between factor V Leiden, factor V HR2, prothrombin G20210A and MTHFR and recurrent fetal loss in a case-control study. Methods: Women aged 22-45 with a history of three or more fetal losses, being seen at a perinatal medicine clinic in New Jersey or Georgia, were eligible as cases. Overall, the study consisted of 60 women with three or more fetal losses and 92 women with at least one successful pregnancy. Results: Factor V HR2 and MTHFR were not related to recurrent fetal loss. The prothrombin G20210A mutation appeared to confer an elevation in risk but the association was based upon small numbers and was not statistically significant (OR 4.8, 95% CI 0.50-47.2). Cases were 90% less likely to have the factor V Leiden mutation than controls (OR 0.10, 95% CI 0.01-0.81). Conclusions: Our study did not demonstrate that women who are carriers of the factor V, prothrombin, or MTHFR mutations are at higher risk of recurrent fetal loss than women without these mutations. In regards to factor V Leiden, the prevalence in our cases (1.7%) was not statistically different from the known population prevalence of 5%. However, the high prevalence in our controls (14%) was unusual. Factor V Leiden may protect against bleeding in early pregnancy.     

The C677T polymorphism of the methylenetetrahydrofolate reductase gene and idiopathic recurrent miscarriage

OBJECTIVE:To investigate the association between the C677T polymorphism of the 5,10-methylenetetrahydrofolate reductase gene (MTHFR), serum homocysteine levels, and idiopathic recurrent miscarriage in a Middle-European white population.METHODS:In a case control study, we investigated 133 women with a history of three or more consecutive pregnancy losses before 20 weeks' gestation and 74 healthy controls with at least two live births and no history of pregnancy loss. A DNA extraction and polymerase chain reaction followed by restriction fragment length polymorphism analysis were used to genotype women for the presence of the MTHFR C677T polymorphism. Serum homocysteine levels were assessed by a fluorescence polarization immunoassay.RESULTS:The MTHFR allele frequencies in women with idiopathic recurrent miscarriage and controls were 34.6% and 21.6%, respectively, for the T allele (mutant) and 65.4% and 78.4%, respectively, for the C allele (wild type) (P =.007, odds ratio 1.9, 95% confidence interval 1.2, 3.1). The MTHFR genotype frequencies in women with idiopathic recurrent miscarriage and controls were: 17.3% (T/T), 34.6% (C/T), 48.1% (C/C) and 5.4% (T/T), 32.4% (C/T), 62.2% (C/C), respectively (P =.03, odds ratio 3.7, 95% confidence interval 1.2, 11.8 [T/T versus C/T and C/C]). Serum concentrations of homocysteine were significantly higher in carriers of a MTHFR mutant allele compared with women with no mutant allele (mean 7.4 +/- 2.4 micromol/L [T/T + C/T] versus 6.5 +/- 2.6 micromol/L [C/C], P =.05).CONCLUSION:Carriage of the mutant allele of the MTHFR C677T polymorphism is associated with elevated serum levels of homocysteine and idiopathic recurrent miscarriage.     

原因不明复发性流产患者血中亚甲基四氢叶酸还原酶基因C677T和A1298C位点突变的研究

目的　探讨 5 ,10 亚甲基四氢叶酸还原酶基因C6 77T和A12 98C位点突变与原因不明复发性流产 (unexplainedrecurrentspontaneousabortion ,URSA)易感因素的相关性。 方法　采用PCR-限制性片段长度多态性方法 ,检测 14 7例原因不明复发性流产患者 (URSA组 )和 82例有正常妊娠史的妇女 (对照组 )血中亚甲基四氢叶酸还原酶基因C6 77T和A12 98C位点突变。结果　 ( 1)C6 77T的 3种基因型在URSA组和对照组总体分布存在显著性差异 (P =0 0 12 ) ,其中URSA组 :基因型CC占 33 3% ,CT占 5 3 1% ,TT占 13 6 % ,对照组 :基因型CC占 5 2 4 % ,CT占 5 1 5 % ,TT占 6 1%。两组 6 77CC基因表达差异有显著性 (P =0 0 0 5 ) ,URSA组C和T等位基因分别为 4 0 1%、5 9 9% ,两组基因分布情况比较 ,差异有显著性 (P <0 0 0 5 ) ;( 2 )A12 98C的 3种基因型在URSA组和对照组中总体分布情况比较 ,差异无显著性 ,12 98AA/AC/CC基因型和A/C等位基因频率比较 ,差异无显著性 (P >0 0 0 5 ) ;( 3)C6 77T/A12 98C连锁基因分析显示 ,8种连锁基因型中 ,URSA组 6 77CC/ 12 98AA表达频率显著降低 ,而 6 77(CT TT) / 12 98CC仅在URSA组中表达。结论　URSA与亚甲基四氢叶酸还原酶基因C6 77T和A12 98C位点突变有关。