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Sample records for reductase mthfr mutation

  1. Pregnancy-associated osteoporosis with a heterozygous deactivating LDL receptor-related protein 5 (LRP5) mutation and a homozygous methylenetetrahydrofolate reductase (MTHFR) polymorphism.

    PubMed

    Cook, Fiona J; Mumm, Steven; Whyte, Michael P; Wenkert, Deborah

    2014-04-01

    Pregnancy-associated osteoporosis (PAO) is a rare, idiopathic disorder that usually presents with vertebral compression fractures (VCFs) within 6 months of a first pregnancy and delivery. Spontaneous improvement is typical. There is no known genetic basis for PAO. A 26-year-old primagravida with a neonatal history of unilateral blindness attributable to hyperplastic primary vitreous sustained postpartum VCFs consistent with PAO. Her low bone mineral density (BMD) seemed to respond to vitamin D and calcium therapy, with no fractures after her next successful pregnancy. Investigation of subsequent fetal losses revealed homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism associated both with fetal loss and with osteoporosis (OP). Because her neonatal unilateral blindness and OP were suggestive of loss-of-function mutation(s) in the gene that encodes LDL receptor-related protein 5 (LRP5), LRP5 exon and splice site sequencing was also performed. This revealed a unique heterozygous 12-bp deletion in exon 21 (c.4454_4465del, p.1485_1488del SSSS) in the patient, her mother and sons, but not her father or brother. Her mother had a normal BMD, no history of fractures, PAO, ophthalmopathy, or fetal loss. Her two sons had no ophthalmopathy and no skeletal issues. Her osteoporotic father (with a family history of blindness) and brother had low BMDs first documented at ages ∼40 and 32 years, respectively. Serum biochemical and bone turnover studies were unremarkable in all subjects. We postulate that our patient's heterozygous LRP5 mutation together with her homozygous MTHFR polymorphism likely predisposed her to low peak BMD. However, OP did not cosegregate in her family with the LRP5 mutation, the homozygous MTHFR polymorphism, or even the combination of the two, implicating additional genetic or nongenetic factors in her PAO. Nevertheless, exploration for potential genetic contributions to PAO may explain part of the pathogenesis of this

  2. Common Mutations of the Methylenetetrahydrofolate Reductase (MTHFR) Gene in Non-Syndromic Cleft Lips and Palates Children in North-West of Iran

    PubMed Central

    Abdollahi-Fakhim, Shahin; Asghari Estiar, Mehrdad; Varghaei, Parizad; Alizadeh Sharafi, Mahdi; Sakhinia, Masoud; Sakhinia, Ebrahim

    2015-01-01

    Introduction: Cleft lips and cleft palates are common congenital abnormalities in children. Various chromosomal loci have been suggested to be responsible the development of these abnormalities. The present study was carried out to investigate the association between the suspected genes (methylenetetrahydrofolate reductase [MTHFR] A1298C and C677T) that might contribute into the etiology of these disorders through application of molecular methods. Materials and Methods: This cross-sectional and explanatory study was carried out on a study population of 65 affected children, 130 respective parents and 50 healthy individuals between 2009 and 2012 at Tabriz University of Medical Sciences, IR Iran. After DNA extraction, amplification refractory mutation system–polymerase chain reaction (ARMS-PCR) and restriction fragment length polymorphism (RFLP)-PCR were used respectively to investigate the C677T and A1298C mutations for the MTHFR gene. Results: There was a significant difference in the rates of the C677T mutation when affected patients and their fathers were compared with the control group (odds ratio [OR]=0.44) (OR=0.64). However, there was no significant difference observed in the rate of this mutation between the patients’ mothers and the control group (OR=1.35). In addition, the abnormality rate was higher in patients with the A1298C mutation and their parents, when compared with the control group. This abnormality rate was higher for the affected children and their fathers in comparison with their mothers (Fathers, OR=0.26; Mothers, OR=0.65; Children, OR=0.55). No significant difference was seen in the rate of the polymorphism C677T in its CC, when the affected children and their parents were compared with the control group. However, there was a significant difference in the A1298C mutation. Conclusion: An association was seen between the A1298C mutation and cleft lip and cleft palate abnormalities in Iran. However, there seems to be a stronger relationship

  3. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism: epidemiology, metabolism and the associated diseases.

    PubMed

    Liew, Siaw-Cheok; Gupta, Esha Das

    2015-01-01

    The Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is associated with various diseases (vascular, cancers, neurology, diabetes, psoriasis, etc) with the epidemiology of the polymorphism of the C677T that varies dependent on the geography and ethnicity. The 5,10-Methylenetetrahydrofolate reductase (MTHFR) locus is mapped on chromosome 1 at the end of the short arm (1p36.6). This enzyme is important for the folate metabolism which is an integral process for cell metabolism in the DNA, RNA and protein methylation. The mutation of the MTHFR gene which causes the C677T polymorphism is located at exon 4 which results in the conversion of valine to alanine at codon 222, a common polymorphism that reduces the activity of this enzyme. The homozygous mutated subjects have higher homocysteine levels while the heterozygous mutated subjects have mildly raised homocysteine levels compared with the normal, non-mutated controls. Hyperhomocysteinemia is an emerging risk factor for various cardiovascular diseases and with the increasing significance of this polymorphism in view of the morbidity and mortality impact on the patients, further prevention strategies and nutritional recommendations with the supplementation of vitamin B12 and folic acid which reduces plasma homocysteine level would be necessary as part of future health education. This literature review therefore focuses on the recent evidence-based reports on the associations of the MTHFR C677T polymorphism and the various diseases globally. PMID:25449138

  4. MTHFR homozygous mutation and additional risk factors for cerebral infarction in a large Italian family.

    PubMed

    Del Balzo, Francesca; Spalice, Alberto; Perla, Massimo; Properzi, Enrico; Iannetti, Paola

    2009-01-01

    Several cases with cerebral infarctions associated with the C677T mutation in the methylenetetrahydrofolate reductase gene (MTHFR) have been reported. Given the large number of asymptomatic individuals with the MTHFR mutation, additional risk factors for cerebral infarction should be considered. This study describes a large family with the MTHFR mutation and a combination of heterozygous factor V Leiden mutations and different additional exogenous and endogenous thrombogenic risk factors. Psychomotor retardation and a left fronto-insular infarct associated with the MTHFR mutation together with diminished factor VII and low level of protein C was documented in the first patient. In the second patient, generalized epilepsy and a malacic area in the right nucleus lenticularis was associated with the MTHFR mutation and a low level of protein C. In the third patient, right hemiparesis and a left fronto-temporal porencephalic cyst were documented, together with the MTHFR mutation and hyperhomocysteinemia. An extensive search of additional circumstantial and genetic thrombogenic risk factors should be useful for prophylaxis and prognosis of infants with cerebral infarctions associated with the MTHFR mutation and of their related family members. PMID:19068258

  5. The role of vitamin B12 in fasting hyperhomocysteinemia and its interaction with the homozygous C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. A case-control study of patients with early-onset thrombotic events.

    PubMed

    D'Angelo, A; Coppola, A; Madonna, P; Fermo, I; Pagano, A; Mazzola, G; Galli, L; Cerbone, A M

    2000-04-01

    Total fasting plasma homocysteine (tHcy), homozygosity for the C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene and for the A2756G mutation of the methionine synthase (MS) gene, vitamin B12 and folate plasma levels were evaluated in 170 consecutive patients (89 M, 81 F; mean age 41 +/- 12 yrs) with documented early-onset thrombosis (89 venous, 69 arterial, 12 both; mean age at first episode 36 +/- 11 yrs), and in 182 age- and sex-matched healthy control subjects. Moderate hyperhomocysteinemia (HHcy, tHcy >19.5 microM in men and >15 microM in women) was detected in 45 patients (26.5%) and in 18 controls (9.9%, Mantel-Haenszel OR and 95% C.I. after stratification for arterial or venous thrombosis: 3.25, 1.78-5.91). The 677TT MTHFR genotype was not significantly more prevalent in patients (27.6%) than in controls (21.4%, RR = 1.42: 0.84-2.41), and markedly contributed to HHcy (Mantel-Haenszel RR after stratification for case/control status: 8.29, 4.61-14.9). The 2756GG MS genotype, observed in 4 patients (2.4%) and 8 controls (4.4%), was not associated to HHcy. tHcy was negatively correlated to folate and vitamin B12 levels, with better correlation found in subjects with the 677TT mutation (r = -0.42 and -0.25) than with the 677CC or CT MTHFR genotype (r = 0).37 and -0.11). However, folate was similar in patients and controls and vitamin B12 was higher in patients (460 +/- 206 vs. 408 +/-185 pg/ml, p = 0.011). In a generalized linear model, 44% of the variation in tHcy levels was explained by folate and vitamin B12 levels, the MTHFR genotype, gender, and by the interaction of the MTHFR genotype with folate (p < or =0.028); the interactions of vitamin B12 with the MTHFR genotype, gender and patient/control status also significantly contributed to the variation in tHcy levels (p < or =0.028). A 4-week administration of 5-methyltetrahydrofolate (15 mg/day) markedly lowered plasma tHcy in 24 patients with MTHFR 677TT genotype, but the response to

  6. MTHFR Gene Mutations: A Potential Marker of Late-Onset Alzheimer's Disease?

    PubMed

    Román, Gustavo C

    2015-01-01

    Recent epigenome-wide association studies have confirmed the importance of epigenetic effects mediated by DNA methylation in late-onset Alzheimer's disease (LOAD). Metabolic folate pathways and methyl donor reactions facilitated by B-group vitamins may be critical in the pathogenesis of LOAD. Methylenetetrahydrofolate reductase (MTHFR) gene mutations were studied in consecutive Alzheimer's Disease & Memory Clinic patients up to December 2014. DNA analyses of MTHFR-C667T and - A1298C homozygous and heterozygous polymorphisms in 93 consecutive elderly patients revealed high prevalence of MTHFR mutations (92.5%). Findings require confirmation in a larger series, but MTHFR mutations may become a LOAD marker, opening novel possibilities for prevention and treatment. PMID:26401555

  7. Bilateral transverse sinus thrombosis secondary to a homozygous C677T MTHFR gene mutation.

    PubMed

    Kanaan, Ziad M; Mahfouz, Rami; Taher, Ali; Sawaya, Raja A

    2008-09-01

    We describe the case of a previously healthy young man who presented with headache, diplopia, nausea, vomiting, and bilateral papilledema. Magnetic resonance venography of the brain revealed thrombosis of the right transverse sinus. Blood tests showed elevated homocysteine levels, and coagulation studies revealed a homozygous C677T mutation and a heterozygous A1298C mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. The patient had no other etiology for venous thrombosis. We recommend screening patients who present with sinus thrombosis for MTHFR gene mutations. PMID:18666857

  8. Coexistence of Neurofibromatosis Type-1 and MTHFR C677T Gene Mutation in a Young Stroke Patient: A Case Report

    PubMed Central

    Yilmaz, Halim; Erkin, Gulten; Gumus, Haluk; Nalbant, Lutfiye

    2013-01-01

    In neurofibromatosis type-1 (NF1), cerebrovascular disorders are rarely encountered although vasculopathy is a well-known complication. Several mutations seen in methylenetetrahydrofolate reductase (MTHFR) give rise to the formation of hyperhomocysteinemia and homocystinuria, a considerable risk factor for cardiovascular and cerebrovascular disorders, by leading to enzymatic inactivation. In the paper, a 31-year-old young stroke female patient with the coexistence of neurofibromatosis and MTHFR C677T gene mutation was presented. PMID:23533858

  9. Internal jugular vein thrombosis due to heterozygote methylene tetrahydrofolate reductase (MTHFR) 1298C and Factor V G1691A mutations after a minor trauma

    PubMed Central

    Gumussoy, Murat; Arslan, Ilker B.; Cukurova, Ibrahim; Uluyol, Sinan

    2014-01-01

    Internal jugular vein thrombosis usually appears in central venous catheterization, distant malignancies, hypercoagulation, infections, or secondary to ovarian hyperstimulation syndrome. A 44-year-old female patient presented to us with sore throat, and pain and swelling on the right side of her neck. She had a history of simple neck trauma 10 days ago. Ultrasonography and computed tomography showed bilateral multiple lymphadenopathies and right internal jugular vein thrombosis. Patient was put on parenteral antibiotherapy and oral anticoagulant treatment. Genomic DNA tests for hypercoagulation revealed methylene tetrahydrofolate reductase 1298C heterozygote mutation and Factor V G1691A (Leiden) mutation. Patient has been under clinical control for 1 year and does not have any complaints. In this article, diagnosis, treatment, and the etiology of internal jugular vein thrombosis, which is a rare and potentially fatal condition, have been discussed through this case. PMID:25937730

  10. Homozygous MTHFR C677T gene mutation and recurrent stroke in an infant.

    PubMed

    Garoufi, Anastasia J; Prassouli, Alexia A; Attilakos, Achilleas V; Voudris, Konstantinos A; Katsarou, Eustathia S

    2006-07-01

    The role of homozygosity for the C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene as an independent risk factor for primary and recurrent stroke has been questioned, although recent data appear to be supportive. However, the association of homozygous C677T MTHFR mutation with silent brain infarctions in infancy has not been reported. The authors describe an 11-month-old male who had suffered a silent brain infarction followed by a symptomatic arterial stroke. The evaluation revealed mildly elevated homocysteine levels secondary to homozygous C677T alleles for MTHFR and iron deficiency anemia. An extensive evaluation for other causes of infarction was negative. We suggest that the mother's homozygous MTHFR status played a role in the early onset of stroke and that iron deficiency anemia may have contributed to the recurrence. The patient was treated with anticoagulation therapy, folic acid, and iron supplementation and has not had a recurrent event during 3 years of follow-up. This case provides further evidence that homozygous MTHFR mutation is a predisposing factor for early and recurrent pediatric stroke, including silent infarcts, especially in the presence of other risk factors. PMID:16814086

  11. Mutation Update and Review of Severe Methylenetetrahydrofolate Reductase Deficiency.

    PubMed

    Froese, D Sean; Huemer, Martina; Suormala, Terttu; Burda, Patricie; Coelho, David; Guéant, Jean-Louis; Landolt, Markus A; Kožich, Viktor; Fowler, Brian; Baumgartner, Matthias R

    2016-05-01

    Severe 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency is caused by mutations in the MTHFR gene and results in hyperhomocysteinemia and varying severity of disease, ranging from neonatal lethal to adult onset. Including those described here, 109 MTHFR mutations have been reported in 171 families, consisting of 70 missense mutations, 17 that primarily affect splicing, 11 nonsense mutations, seven small deletions, two no-stop mutations, one small duplication, and one large duplication. Only 36% of mutations recur in unrelated families, indicating that most are "private." The most common mutation is c.1530A>G (numbered from NM_005957.4, p.Lys510 = ) causing a splicing defect, found in 13 families; the most common missense mutation is c.1129C>T (p.Arg377Cys) identified in 10 families. To increase disease understanding, we report enzymatic activity, detected mutations, and clinical onset information (early, <1 year; or late, >1 year) for all published patients available, demonstrating that patients with early onset have less residual enzyme activity than those presenting later. We also review animal models, diagnostic approaches, clinical presentations, and treatment options. This is the first large review of mutations in MTHFR, highlighting the wide spectrum of disease-causing mutations. PMID:26872964

  12. Meta-Prediction of MTHFR Gene Polymorphism Mutations and Associated Risk for Colorectal Cancer

    PubMed Central

    Yu, C. H.

    2016-01-01

    The methylenetetrahydrofolate reductase (MTHFR) gene is one of the most investigated of the genes associated with chronic human diseases because of its associations with hyperhomocysteinemia and toxicity. It has been proposed as a prototype gene for the prevention of colorectal cancer (CRC). The major objectives of this meta-analysis were to examine the polymorphism-mutation patterns of MTHFR and their associations with risk for CRC as well as potential contributing factors for mutations and disease risks. This analysis included 33,626 CRC cases and 48,688 controls across 92 studies for MTHFR 677 and 16,367 cases and 24,874 controls across 54 studies for MTHFR 1298, comprising data for various racial and ethnic groups, both genders, and multiple cancer sites. MTHFR 677 homozygous TT genotype was protective (p < .05) for CRC for all included populations; however, with heterogeneity across various racial–ethnic groups and opposing findings, it was a risk genotype for the subgroup of Hispanics (p < .01). Additional countries for which subgroup analyses resulted in 677 TT as a risk genotype included Turkey, Romania, Croatia, Hungary, Portugal, Mexico, Brazil, U.S. Hawai’i, Taiwan, India, and Egypt. Countries with the highest mutation rates and risks for both MTHFR 677 and 1298 genotypes are presented using global maps to visualize the grouping patterns. Meta-predictive analyses revealed that air pollution levels were associated with gene polymorphisms for both genotypes. Future nursing research should be conducted to develop proactive measures to protect populations in cities where air pollution causes more deaths. PMID:26858257

  13. Meta-Prediction of MTHFR Gene Polymorphism Mutations and Associated Risk for Colorectal Cancer.

    PubMed

    Shiao, S P K; Yu, C H

    2016-07-01

    The methylenetetrahydrofolate reductase (MTHFR) gene is one of the most investigated of the genes associated with chronic human diseases because of its associations with hyperhomocysteinemia and toxicity. It has been proposed as a prototype gene for the prevention of colorectal cancer (CRC). The major objectives of this meta-analysis were to examine the polymorphism-mutation patterns of MTHFR and their associations with risk for CRC as well as potential contributing factors for mutations and disease risks. This analysis included 33,626 CRC cases and 48,688 controls across 92 studies for MTHFR 677 and 16,367 cases and 24,874 controls across 54 studies for MTHFR 1298, comprising data for various racial and ethnic groups, both genders, and multiple cancer sites. MTHFR 677 homozygous TT genotype was protective (p <05) for CRC for all included populations; however, with heterogeneity across various racial-ethnic groups and opposing findings, it was a risk genotype for the subgroup of Hispanics (p <01). Additional countries for which subgroup analyses resulted in 677 TT as a risk genotype included Turkey, Romania, Croatia, Hungary, Portugal, Mexico, Brazil, U.S. Hawai'i, Taiwan, India, and Egypt. Countries with the highest mutation rates and risks for both MTHFR 677 and 1298 genotypes are presented using global maps to visualize the grouping patterns. Meta-predictive analyses revealed that air pollution levels were associated with gene polymorphisms for both genotypes. Future nursing research should be conducted to develop proactive measures to protect populations in cities where air pollution causes more deaths. PMID:26858257

  14. Methylenetetrahydrofolate reductase mutations, a genetic cause for familial recurrent neural tube defects

    PubMed Central

    Yaliwal, Laxmi V.; Desai, Rathnamala M.

    2012-01-01

    Methylenetetrahydrofolate reductase (MTHFR) gene mutations have been implicated as risk factors for neural tube defects (NTDs). The best-characterized MTHFR genetic mutation 677C→T is associated with a 2–4 fold increased risk of NTD if patient is homozygous for this mutation. This risk factor is modulated by folate levels in the body. A second mutation in the MTHFR gene is an A→C transition at position 1298. The 1298A→C mutation is also a risk factor for NTD, but with a smaller relative risk than 677C→T mutation. Under conditions of low folate intake or high folate requirements, such as pregnancy, this mutation could become of clinical importance. We present a case report with MTHFR genetic mutation, who presented with recurrent familial pregnancy losses due to anencephaly/NTDs. PMID:22754237

  15. Methylenetetrahydrofolate reductase homozygous mutation in a young boy with cerebellar infarction.

    PubMed

    Spalice, Alberto; Del Balzo, Francesca; Perla, Francesco Massimo; Properzi, Enrico; Carducci, Carla; Antonozzi, Italo; Iannetti, Paola

    2009-01-01

    Posterior circulation vascular occlusive disease in children is a rare and uncommonly reported event. Among the numerous risk factors, the methylenetetrahydrofolate reductase (MTHFR) mutation is considered to be a common genetic cause of thrombosis in adults and children. Recently, a link between the MTHFR mutation and cerebrovascular disorders was reported in children. Diffusion tensor imaging (DTI) is a great improvement on magnetic resonance imaging (MRI), making the in vivo anatomical and pathological study of the brain and its fibers possible. In our patient cerebellar infarction was associated with MTHFR mutation and, in a standard neurological examination, DTI revealed normal white matter tracts. PMID:21589820

  16. Methylenetetrahydrofolate reductase homozygous mutation in a young boy with cerebellar infarction

    PubMed Central

    Spalice, Alberto; Del Balzo, Francesca; Perla, Francesco Massimo; Properzi, Enrico; Carducci, Carla; Antonozzi, Italo; Iannetti, Paola

    2009-01-01

    Posterior circulation vascular occlusive disease in children is a rare and uncommonly reported event. Among the numerous risk factors, the methylenetetrahydrofolate reductase (MTHFR) mutation is considered to be a common genetic cause of thrombosis in adults and children. Recently, a link between the MTHFR mutation and cerebrovascular disorders was reported in children. Diffusion tensor imaging (DTI) is a great improvement on magnetic resonance imaging (MRI), making the in vivo anatomical and pathological study of the brain and its fibers possible. In our patient cerebellar infarction was associated with MTHFR mutation and, in a standard neurological examination, DTI revealed normal white matter tracts. PMID:21589820

  17. Association between 5, 10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms and congenital heart disease: A meta-analysis☆

    PubMed Central

    Wang, Wenju; Hou, Zongliu; Wang, Chunhui; Wei, Chuanyu; Li, Yaxiong; Jiang, Lihong

    2013-01-01

    Background Inconsistent results were reported in recent literature regarding the association between methylenetetrahydrofolate reductase (MTHFR) C677T/A1298C polymorphisms and the susceptibility of congenital heart disease (CHD). In this study, we performed a meta-analysis to investigate the associations by employing multiple analytical methods. Methods Literature search was performed and published articles were obtained from PubMed, Embase and CNKI databases based on the exclusion and inclusion criteria. Data were extracted from eligible studies and the crude odds ratios and their corresponding 95% confidence intervals (CIs) were calculated using random or fix effects model to evaluate the associations between the MTHFR C677T/A1298C polymorphisms and CHD development. Subgroup based analysis was performed by Hardy–Weinberg equilibrium, ethnicity, types of CHD, source of control and sample size. Results Twenty-four eligible studies were included in this meta-analysis. Significant association was found between fetal MTHFR C677T polymorphism and CHD development in all genetic models. The pooled ORs and 95% CIs in all genetic models indicated that MTHFR C677T polymorphism was significantly associated with CHD in Asian, but not Caucasian in subgroup analysis. The maternal MTHFR C677T polymorphism was not associated with CHD except for recessive model. Moreover, neither maternal nor fetal MTHFR A1298C polymorphism was associated with CHD. Conclusion The fetal MTHFR C677T polymorphism may increase the susceptibility to CHD. Fetal MTHFR C677T polymorphism was more likely to affect Asian fetus than Caucasian. The MTHFR A1298C polymorphism may not be a risk of congenital heart disease. PMID:25606381

  18. Intracardiac Thrombosis Involving All Four Cardiac Chambers after Extracardiac Membranous Oxygenation Associated with MTHFR Mutations

    PubMed Central

    Kim, Bong Jun; Song, Seung Hwan; Shin, Yu Rim; Park, Han Ki; Park, Young Hwan; Shin, Hong Ju

    2016-01-01

    A 4-month-old boy diagnosed with acute myocarditis was treated with extracorporeal membrane oxygenation (ECMO). Follow-up echocardiography eight hours after ECMO revealed intracardiac thrombosis involving all four heart chambers. Because of the high risk of systemic embolization due to a pedunculated thrombus of the aortic valve, we performed an emergency thrombectomy. After the operation, the patient had a minor neurologic sequela of left upper arm hypertonia, which had almost disappeared at the last outpatient clinic two months later. He was diagnosed with a major mutation in MTHFR (methylenetetrahydrofolate reductase), which is related to thrombosis. PMID:27298801

  19. Intracardiac Thrombosis Involving All Four Cardiac Chambers after Extracardiac Membranous Oxygenation Associated with MTHFR Mutations.

    PubMed

    Kim, Bong Jun; Song, Seung Hwan; Shin, Yu Rim; Park, Han Ki; Park, Young Hwan; Shin, Hong Ju

    2016-06-01

    A 4-month-old boy diagnosed with acute myocarditis was treated with extracorporeal membrane oxygenation (ECMO). Follow-up echocardiography eight hours after ECMO revealed intracardiac thrombosis involving all four heart chambers. Because of the high risk of systemic embolization due to a pedunculated thrombus of the aortic valve, we performed an emergency thrombectomy. After the operation, the patient had a minor neurologic sequela of left upper arm hypertonia, which had almost disappeared at the last outpatient clinic two months later. He was diagnosed with a major mutation in MTHFR (methylenetetrahydrofolate reductase), which is related to thrombosis. PMID:27298801

  20. Methylenetetrahydrofolate reductase (MTHFR) polymorphism susceptibility to schizophrenia and bipolar disorder: an updated meta-analysis.

    PubMed

    Hu, Cai-Yun; Qian, Zhen-Zhong; Gong, Feng-Feng; Lu, Shan-Shan; Feng, Fang; Wu, Yi-Le; Yang, Hui-Yun; Sun, Ye-Huan

    2015-02-01

    Previous studies examining the possible role of the methylenetetrahydrofolate reductase (MTHFR) polymorphisms in the development of schizophrenia (SZ) and bipolar disorder (BPD) have provided inconclusive findings, this meta-analysis was therefore designed to get a more reliable assessment. A total of 38 articles were identified through a search of electronic databases, up to 27 February 2014. Odds ratios (ORs) with 95% confidence interval (CIs) were calculated using random effects models. Meta-analysis showed that MTHFR C677T was significantly associated with SZ, the highest OR was found for the recessive model (for TT vs. CT + CC: OR = 1.34, 95% CI: 1.18-1.53); a marginal association of MTHFR C677T with increased risk of BPD has also been found for the recessive model (OR = 1.26, 95% CI: 1.00-1.59). Subgroup analysis by ethnicity indicated that the significant association with SZ and BPD existed among Asian and African populations, but not for the white. MTHFR A1298C was significant associated with SZ, the highest OR for the dominant model (OR = 1.13, 95% CI: 1.03-1.24). Subgroup analysis indicated a significant association with SZ existed in Asian populations, not among the white populations and no significant association was detected between the MTHFR A1298C and BPD in all groups. We conclude that MTHFR polymorphism is associated with SZ and BPD among Asian, African populations, but not the white. PMID:24938371

  1. Plasma folate, methylenetetrahydrofolate reductase (MTHFR), and colorectal cancer risk in three large nested case-control studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few prospective studies have examined the associations between blood levels of folate, in conjunction with methylenetetrahydrofolate reductase (MTHFR) polymorphisms, and colorectal cancer. We evaluated the associations between plasma folate, MTHFR C677T, and A1298C, and colorectal cancer in three la...

  2. Methylenetetrahydrofolate reductase (MTHFR) genetic polymorphisms and psychiatric disorders: a HuGE review.

    PubMed

    Gilbody, Simon; Lewis, Sarah; Lightfoot, Tracy

    2007-01-01

    The authors performed a meta-analysis of studies examining the association between polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, including MTHFR C677T and A1298C, and common psychiatric disorders, including unipolar depression, anxiety disorders, bipolar disorder, and schizophrenia. The primary comparison was between homozygote variants and the wild type for MTHFR C677T and A1298C. For unipolar depression and the MTHFR C677T polymorphism, the fixed-effects odds ratio for homozygote variants (TT) versus the wild type (CC) was 1.36 (95% confidence interval (CI): 1.11, 1.67), with no residual between-study heterogeneity (I(2) = 0%)--based on 1,280 cases and 10,429 controls. For schizophrenia and MTHFR C677T, the fixed-effects odds ratio for TT versus CC was 1.44 (95% CI: 1.21, 1.70), with low heterogeneity (I(2) = 42%)--based on 2,762 cases and 3,363 controls. For bipolar disorder and MTHFR C677T, the fixed-effects odds ratio for TT versus CC was 1.82 (95% CI: 1.22, 2.70), with low heterogeneity (I(2) = 42%)-based on 550 cases and 1,098 controls. These results were robust to various sensitively analyses. This meta-analysis demonstrates an association between the MTHFR C677T variant and depression, schizophrenia, and bipolar disorder, raising the possibility of the use of folate in treatment and prevention. PMID:17074966

  3. Is methylenetetrahydrofolate reductase (MTHFR) gene A1298C polymorphism related with varicocele risk?

    PubMed

    Ucar, V B; Nami, B; Acar, H; Kilinç, M

    2015-02-01

    Varicocele is one of the main reasons for male infertility the exact aetiology of which remains unclear. Methylenetetrahydrofolate reductase (MTHFR) is important for DNA synthesis and methylation, which has a key role during spermatogenesis. Numerous literature suggests that the MTHFR polymorphism may be genetic risk factors for male infertility. In this study, we evaluated C677T and A1298C MTHFR gene polymorphism frequency in patients with varicocele and normal men. A total of 107 varicocele patients and 109 fertile healthy individuals were included. Genotyping of the MTHFR gene in C677T and A1298C base pairs carried out by using real-time PCR technique and afterwards, the statistical analysis accomplished. There is a statistical difference for the frequency of 1298AA genotype in patients with varicocele compared with normal controls (P = 0.0051, OR = 2.2750). Instead, subsequently, 1298/A allel frequency in patient group was significantly higher in comparison with control group (P = 0.0174). According to our results, 1298AA genotype in MTHFR gene raises the risk of varicocele approximately 2.3 times more compared with men carrying other genotypes. The results show that genetic factors have an important role in the molecular basis of varicocele. PMID:24456105

  4. Association of C677T transition of the human methylenetetrahydrofolate reductase (MTHFR) gene with male infertility.

    PubMed

    Karimian, Mohammad; Colagar, Abasalt Hosseinzadeh

    2016-04-01

    The human methylenetetrahydrofolate reductase (MTHFR) gene encodes one of the key enzymes in folate metabolism. This gene is located on chromosome 1 (1p36.3), which has 12 exons. The aim of the present study was to investigate the possible association of the two (C677T and A1298C) polymorphisms of this gene with male infertility. In a case-control study, 250 blood samples were collected from IVF centres in Sari and Babol (Iran): 118 samples were from oligospermic men and 132 were from controls. Two single nucleotide polymorphisms of the MTHFR genotype were detected using polymerase chain reaction-restriction fragment length polymorphism. There was no association found between the A1298C variant and male infertility. However, carriers of the 677T allele (CT and TT genotypes) were at a higher risk of infertility than individuals with other genotypes (odds ratio 1.84; 95% confidence interval 1.11-3.04; P=0.0174). Structural analysis of human MTHFR flavoprotein showed that C677T transition played an important role in the change in affinity of the MTHFR-Flavin adenine dinucleotide binding site. Based on our results, we suggest that C677T transition in MTHFR may increase the risk of male infertility, and detection of the C677T polymorphism biomarker may be helpful in the screening of idiopathic male infertility. PMID:25412139

  5. Associations between Methylenetetrahydrofolate Reductase (MTHFR) Polymorphisms and Non-Alcoholic Fatty Liver Disease (NAFLD) Risk: A Meta-Analysis

    PubMed Central

    Sun, Man-Yi; Zhang, Li; Shi, Song-Li; Lin, Jing-Na

    2016-01-01

    Background C677T and A1298C are the most common allelic variants of Methylenetetrahydrofolate Reductase (MTHFR) gene. The association between MTHFR polymorphisms and the occurrence of non-alcoholic fatty liver disease (NAFLD) remains controversial. This study was thus performed to examine whether MTHFR mutations are associated with the susceptibility to NAFLD. Methods A first meta-analysis on the association between the MTHFR polymorphisms and NAFLD risks was carried out via Review Manager 5.0 and Stata/SE 12.0 software. The on-line databases, such as PubMed, EMBASE, CENTRAL, WOS, Scopus and EBSCOhost (updated to April 1st, 2016), were searched for eligible case-control studies. The odd radio (OR), 95% confidence interval (CI) and P value were calculated through Mantel-Haenszel statistics under random- or fixed-effect model. Results Eight articles (785 cases and 1188 controls) contributed data to the current meta-analysis. For C677T, increased NAFLD risks were observed in case group under homozygote model (T/T vs C/C, OR = 1.49, 95% CI = 1.03~2.15, P = 0.04) and recessive model (T/T vs C/C+C/T, OR = 1.42, 95% CI = 1.07~1.88, P = 0.02), but not the other genetics models, compared with control group. For A1298C, significantly increased NAFLD risks were detected in allele model (C vs A, OR = 1.53, 95% CI = 1.13~2.07, P = 0.006), homozygote model (C/C vs A/A, OR = 2.81, 95% CI = 1.63~4.85, P = 0.0002), dominant model (A/C+C/C vs A/A, OR = 1.60, 95% CI = 1.06~2.41, P = 0.03) and recessive model (C/C vs A/A+A/C, OR = 2.08, 95% CI = 1.45~3.00, P<0.0001), but not heterozygote model. Conclusion T/T genotype of MTHFR C677T polymorphism and C/C genotype of MTHFR A1298C are more likely to be associated with the susceptibility to NAFLD. PMID:27128842

  6. Seven novel mutations in the methylenetetrahydrofolate reductase gene and genotype/phenotype correlations in severe methylenetetrahydrofolate reductase deficiency

    SciTech Connect

    Goyette, P.; Frosst, P.; Rosenblatt, D.S.; Rozen. R.

    1995-05-01

    5-Methyltetrahydrofolate, the major form of folate in plasma, is a carbon donor for the remethylation of homocysteine to methionine. This form of folate is generated from 5,10-methylenetetrahydrofolate through the action of 5,10-methylenetetrahydrofolate reductase (MTHFR), a cytosolic flavoprotein. Patients with an autosomal recessive severe deficiency of MTHFR have homocystinuria and a wide range of neurological and vascular disturbances. We have recently described the isolation of a cDNA for MTHFR and the identification of two mutations in patients with severe MTHFR deficiency. We report here the characterization of seven novel mutations in this gene: six missense mutations and a 5{prime} splice-site defect that activates a cryptic splice in the coding sequence. We also present a preliminary analysis of the relationship between genotype and phenotype for all nine mutations identified thus far in this gene. A nonsense mutation and two missense mutations (proline to leucine and threonine to methionine) in the homozygous state are associated with extremely low activity (0%-3%) and onset of symptoms within the 1st year of age. Other missense mutations (arginine to cysteine and arginine to glutamine) are associated with higher enzyme activity and later onset of symptoms. 19 refs., 4 figs., 2 tabs.

  7. Retrospective approach to methylenetetrahydrofolate reductase mutations in children.

    PubMed

    Özer, Işıl; Özçetin, Mustafa; Karaer, Hatice; Kurt, Semiha G; Şahin, Şemsettin

    2011-07-01

    Methylenetetrahydrofolate reductase reduces methyltetrahydrofolate, a cosubstrate in the remethylation of homocysteine, from methylenetetrahydrofolate. Congenital defects, hematologic tumors, and intrauterine growth retardation can occur during childhood. This study evaluated clinical and laboratory treatment approaches in children diagnosed with methylenetetrahydrofolate reductase mutations. Our group included 23 boys and 14 girls, aged 103.4 ± 70.8 months S.D. Clinical findings of patients and homocysteine, vitamin B12, folate, hemogram, electroencephalography, cranial magnetic resonance imaging, and echocardiography data were evaluated in terms of treatment approach. Our patients' findings included vitamin B12 at 400.4 ± 224.6 pg/mL S.D. (normal range, 300-700 pg/mL), folate at 10.1 ± 4.5 ng/mL S.D. (normal range, 1.8-9 ng/mL), and homocysteine at 8.4 ± 4.7 μmol/L S.D. (normal range, 5.5-17 μmol/L). Eighty-eight percent of patients demonstrated clinical findings. In comparisons involving categorical variables between groups, χ(2) tests were used. No relationship was evident between mutation type, laboratory data, and clinical severity. All mothers who had MTHFR mutations and had babies with sacral dimples had taken folate supplements during pregnancy. To avoid the risk of neural tube defects, pregnant women with a MTHFR mutation may require higher than normally recommended doses of folic acid supplementation for optimum health. PMID:21723457

  8. Methylenetetrahydrofolate Reductase (MTHFR) Polymorphisms and Susceptibility for Cervical Lesions: A Meta-Analysis

    PubMed Central

    Liu, Xiaojiao; Yang, Pei

    2012-01-01

    Background The association between the methylenetetrahydrofolate reductase (MTHFR) C677T/A1298C polymorphisms and the susceptibility to cervical lesions was unclear. This study was designed to investigate their precise association using a large-scale meta-analysis. Methods The previous 16 studies were identified by searching PubMed, Embase and CBM databases. The crude odds ratios and their corresponding 95% confidence intervals (CIs) were used to estimate the association between the MTHFR C677T/A1298C polymorphisms and the susceptibility to the cervical lesions. The subgroup analyses were made on the following: pathological history, geographic region, ethnicity, source of controls and source of DNA for genotyping. Results Neither of the polymorphisms had a significant association with the susceptibility to the cervical lesions in all genetic models. Similar results were found in the subgroup analyses. No association was found between the MTHFR C677T polymorphism and the cervical lesions in the Asia or the America populations though a significant inverse association was found in the Europe population (additive model: P = 0.006, OR = 0.83, 95% CI = 0.72–0.95; CT vs. CC: P = 0.05, OR = 0.83, 95% CI = 0.69–1.00; TT vs. CC: P = 0.05, OR = 0.73, 95% CI = 0.53–1.00). Interestingly, women with the MTHFR A1298C polymorphisms had a marginally increased susceptibility to invasive cancer (ICC) when compared with no carriers but no statistically significant difference in the dominant model (P = 0.06, OR = 1.21, 95% CI = 0.99–1.49) and AC vs. AA (P = 0.09, OR = 1.21, 95% CI = 0.97–1.51). Conclusions The MTHFR C677T and A1298C polymorphisms may not increase the susceptibility to cervical lesions. However, the meta-analysis reveals a negative association between the MTHFR C677T polymorphisms and the cervical lesions, especially in the European populations. The marginal association between the MTHFR A1298C

  9. Serum homocysteine, vitamin B12, folic acid levels and methylenetetrahydrofolate reductase (MTHFR) gene polymorphism in vitiligo.

    PubMed

    Yasar, Ali; Gunduz, Kamer; Onur, Ece; Calkan, Mehmet

    2012-01-01

    The aim of this study was to determine serum vitamin B12, folic acid and homocysteine (Hcy) levels as well as MTHFR (C677, A1298C) gene polymorphisms in patients with vitiligo, and to compare the results with healthy controls. Forty patients with vitiligo and 40 age and sex matched healthy subjects were studied. Serum vitamin B12 and folate levels were determined by enzyme-linked immunosorbent assay. Plasma Hcy levels and MTHFR polymorphisms were determined by chemiluminescence and real time PCR methods, respectively. Mean serum vitamin B12 and Hcy levels were not significantly different while folic acid levels were significantly lower in the control group. There was no significant relationship between disease activity and vitamin B12, folic acid and homocystein levels. No significant difference in C677T gene polymorphism was detected. Heterozygote A1298C gene polymorphism in the patient group was statistically higher than the control group. There was no significant relationship between MTHFR gene polymorphisms and vitamin B12, folic acid and homocysteine levels. In conclusion, vitamin B12, folate and Hcy levels are not altered in vitiligo and MTHFR gene mutations (C677T and A1298C) do not seem to create susceptibility for vitiligo. PMID:22846211

  10. Haplotype analysis of the 5,10-methylenetetrahydrofolate reductase (MTHFR) c.1298A>C (E429A) polymorphism

    PubMed Central

    2011-01-01

    Background The polymorphism 5,10-methylenetetrahydrofolate reductase (MTHFR) c.1298A>C is associated with various diseases. 45 DNA samples homozygous for the A allele and 40 DNA probes homozygous for the C allele were taken from healthy German subjects of white Caucasian origin to analyze the haplotype of the two MTHFR c.1298A>C alleles. Samples were genotyped for the polymorphism MTHFR c.677C>T and for the silent polymorphisms MTHFR c.129C>T, IVS2 533 G>A, c.1068C>T and IVS10 262C>G. Findings Haplotype construction revealed that the C-allele of MTHFR c.1298A>C was more frequently observed in cis with c.129T, IVS2 533A, c.677C, c.1068T, and IVS10 262 G than expected from normal distribution. Estimation of the most recent common ancestor with the DMLE + 2.3 program resulted in an estimated age of approximately 36,660 years of the MTHFR c.1298C allele. Conclusion Given that the era from 30,000 to 40,000 years ago is characterised by the spread of modern humans in Europe and that the prevalence of the MTHFR c.1298C allele is significantly higher in Central Europe in comparison to African populations, a selective advantage of MTHFR c.1298C could be assumed, e. g. by adaption to changes in the nutritional environment. The known founder ancestry of the T allele of MTHFR c.677C>T allele, together with the present data suggests that the MTHFR mutant alleles c.677T and 1298C arose from two independent ancestral alleles, that both confer a selective advantage. PMID:22023786

  11. Association of methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism with autism: evidence of genetic susceptibility.

    PubMed

    Rai, Vandana

    2016-08-01

    Autism (MIM 209850) is a heterogeneous neurodevelopmental disease that manifests within the first 3 years of life. Numerous articles reported that dysfunctional folate-methionine pathway enzymes may play an important role in the pathophysiology of autism. Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme of this pathway and MTHFR C677T polymorphism reported as risk factor for autism in several case control studies. However, controversial reports were also published. Hence the present meta-analysis was designed to investigate the relationship of the MTHFR C677T polymorphism with the risk of autism. Electronic databases were searched for case control studies with following search terms - 'MTHFR', 'C677T', in combination with 'Autism'. Pooled OR with its corresponding 95 % CI was calculated and used as association measure to investigate the association between MTHFR C677T polymorphism and risk of autism. Total of thirteen studies were found suitable for the inclusion in the present meta-analysis, which comprises 1978 cases and 7257 controls. Meta-analysis using all four genetic models showed significant association between C677T polymorphism and autism (ORTvs.C = 1.48; 95 % CI: 1.18-1.86; P = 0.0007; ORTT + CT vs. CC = 1.70, 95 % CI = 0.96-2.9, p = 0.05; ORTT vs. CC = 1.84, 95 % CI = 1.12-3.02, p = 0.02; ORCT vs.CC = 1.60, 95 % CI = 1.2-2.1, p = 0.003; ORTT vs.CT+CC = 1.5, 95 % CI = 1.02-2.2, p = 0.03). In total 13 studies, 9 studies were from Caucasian population and 4 studies were from Asian population. The association between C677T polymorphism and autism was significant in Caucasian (ORTvs.C = 1.43; 95 % CI = 1.1-1.87; p = 0.009) and Asian population (ORTvs.C = 1.68; 95 % CI = 1.02-2.77; p = 0.04) using allele contrast model. In conclusion, present meta-analysis strongly suggested a significant association of the MTHFR C677T polymorphism with autism. PMID:26956130

  12. Methylenetetrahydrofolate reductase (MTHFR) polymorphisms and risk of molecularly defined subtypes of childhood acute leukemia.

    PubMed

    Wiemels, J L; Smith, R N; Taylor, G M; Eden, O B; Alexander, F E; Greaves, M F

    2001-03-27

    Low folate intake as well as alterations in folate metabolism as a result of polymorphisms in the enzyme methylenetetrahydrofolate reductase (MTHFR) have been associated with an increased incidence of neural tube defects, vascular disease, and some cancers. Polymorphic variants of MTHFR lead to enhanced thymidine pools and better quality DNA synthesis that could afford some protection from the development of leukemias, particularly those with translocations. We now report associations of MTHFR polymorphisms in three subgroups of pediatric leukemias: infant lymphoblastic or myeloblastic leukemias with MLL rearrangements and childhood lymphoblastic leukemias with either TEL-AML1 fusions or hyperdiploid karyotypes. Pediatric leukemia patients (n = 253 total) and healthy newborn controls (n = 200) were genotyped for MTHFR polymorphisms at nucleotides 677 (C-->T) and 1,298 (A-->C). A significant association for carriers of C677T was demonstrated for leukemias with MLL translocations (MLL+, n = 37) when compared with controls [adjusted odd ratios (OR) = 0.36 with a 95% confidence interval (CI) of 0.15-0.85; P = 0.017]. This protective effect was not evident for A1298C alleles (OR = 1.14). In contrast, associations for A1298C homozygotes (CC; OR = 0.26 with a 95% CI of 0.07--0.81) and C677T homozygotes (TT; OR = 0.49 with a 95% CI of 0.20--1.17) were observed for hyperdiploid leukemias (n = 138). No significant associations were evident for either polymorphism with TEL-AML1+ leukemias (n = 78). These differences in allelic associations may point to discrete attributes of the two alleles in their ability to alter folate and one-carbon metabolite pools and impact after DNA synthesis and methylation pathways, but should be viewed cautiously pending larger follow-up studies. The data provide evidence that molecularly defined subgroups of pediatric leukemias have different etiologies and also suggest a role of folate in the development of childhood leukemia. PMID:11274424

  13. Methylenetetrahydrofolate reductase (MTHFR) polymorphisms and promoter methylation in cervical oncogenic lesions and cancer

    PubMed Central

    Botezatu, Anca; Socolov, Demetra; Iancu, Iulia V; Huica, Irina; Plesa, Adriana; Ungureanu, Carmen; Anton, Gabriela

    2013-01-01

    The aim of this study was to investigate the role of methylenetetrahydrofolate reductase (MTHFR) polymorphisms and MTHFR methylation pattern in cervical lesions development among women from Romania, a country with high prevalence of human papillomavirus (HPV) cervical infections. To achieve this goal, blood samples and cervical cytology specimens (n = 77)/tumour tissue specimens (n = 23) were investigated. As control, blood and negative cytological smears (n = 50) were used. A statistically significant association was found between T allele of C677T polymorphism and cervical lesions, heterozygote women presenting a threefold increased risk (normal/cervical lesions and tumours: wild homozygote 34/41 (0.68/0.41), heterozygote 14/51 (0.28/0.51), mutant homozygote 2/8 (0.04/0.08); OR = 3.081, P = 0.0035). Using χ square test for the control group, the HPV-negative and HPV-positive patients with cervix lesions, a significant correlation between viral infection and T allele of C677T polymorphism (P = 0.0287) was found. The MTHFR promoter was methylated in all HGSIL and tumour samples, significant differences being noted between HPV-positive samples, control group and cases of cervical dysplastic lesions without HPV DNA (P < 0. 0001) and between samples from patients with high-risk (hr)HPV versus low-risk (lr)HPV (P = 0.0026). No correlations between polymorphisms and methylation were observed. In Romania, individuals carrying T allele are susceptible for cervical lesions. MTHFR promoter methylation is associated with cervical severity lesions and with hrHPV. PMID:23444906

  14. Risk of colorectal cancer associated with the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in the Kashmiri population.

    PubMed

    Sameer, A S; Shah, Z A; Nissar, S; Mudassar, S; Siddiqi, M A

    2011-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in folate metabolism and is involved in DNA synthesis, DNA repair and DNA methylation. The two common functional polymorphisms of MTHFR, 677 C→T and 1298 A→C, have been shown to impact various diseases, including cancer. The 677 C→T polymorphism has been widely investigated in different cancers and has been implicated as a risk factor for the development of various cancers. We investigated MTHFR C677T genotype frequency in colorectal cancer cases in the Kashmiri population and correlated this information with the known clinicopathological characters of colorectal cancer, in a case-control study. Eighty-six colorectal cancer cases were studied for MTHFR C677T polymorphism, compared to 160 controls taken from the general population, employing the PCR-RFLP technique. We found the frequency of the three different genotypes of MTHFR in our ethnic Kashmir population, i.e., CC, CT and TT, to be 68.6, 20.9 and 10.4% among colorectal cancer cases and 75.6, 16.9 and 7.5% among the general control population, respectively. There was a significant association between the MTHFR TT genotype and colorectal cancer in the higher age group. We conclude that the MTHFR C677T polymorphism slightly increases the risk for colorectal cancer development in our ethnic Kashmir population. PMID:21732284

  15. Genetic variants in 3′-UTRs of methylenetetrahydrofolate reductase (MTHFR) predict colorectal cancer susceptibility in Koreans

    PubMed Central

    Joo Jeon, Young; Woo Kim, Jong; Mi Park, Hye; Kim, Jung O; Geun Jang, Hyo; Oh, Jisu; Gyu Hwang, Seong; Won Kwon, Sung; Oh, Doyeun; Keun Kim, Nam

    2015-01-01

    Polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) play important roles in tumor development, progression, and metastasis. Moreover, recent studies have reported that a number of 3′-UTR polymorphisms potentially bind to specific microRNAs in a variety of cancers. The aim of this study was to investigate the association of four MTHFR polymorphisms, 2572C>A [rs4846049], 4869C>G [rs1537514], 5488C>T [rs3737967], and 6685T>C [rs4846048] with colorectal cancer (CRC) in Koreans. A total of 850 participants (450 CRC patients and 400 controls) were enrolled in the study. The genotyping of MTHFR 3′-UTR polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism analysis or TaqMan allelic discrimination assay. We found that MTHFR 2572C>A, 4869C>G, and 5488C>T genotypes were substantially associated with CRC susceptibility. Of the potentially susceptible polymorphisms, MTHFR 2572C>A was associated with increased homocysteine and decreased folate levels in the plasma based on MTHFR 677CC. Our study provides the evidences for 3′-UTR variants in MTHFR gene as potential biomarkers for use in CRC prevention. PMID:26046315

  16. Evidence of Paternal N5, N10 - Methylenetetrahydrofolate Reductase (MTHFR) C677T Gene Polymorphism in Couples with Recurrent Spontaneous Abortions (RSAs) in Kolar District- A South West of India

    PubMed Central

    Vanilla, Shiny; Kotur, Pushpa F; Kutty, Moideen A; Vegi, Pradeep Kumar

    2015-01-01

    Introduction: Recurrent spontaneous abortion (RSA) is a multifactorial clinical obstetrics complication commonly occurring in pregnancy. Many research studies have noted the mutations such as C677T in N5, N10 - Methylenetetrahydrofolate reductase (MTHFR)gene which is regarded as RSA risk factor. This study was carried out to determine the occurrence of frequency of C677T of the MTHFR gene mutations with RSA. Aim: The purpose of present study is to determine the frequency of MTHFR C677T polymorphisms in couples with recurrent pregnancy loss and the impact of paternal polymorphisms of MTHFR C677T in recurrent pregnancy loss in population of couples living in Kolar district of Karnataka with RSA. Design: A total of 15 couples with a history of two or more unexplained RSA were enrolled as subjects in the study and a total of 15 couples with normal reproductive history, having two or more children and no history of miscarriages were enrolled as controls. Materials and Methods: DNA extraction from samples case and control group couples and its quantification by Agarose gel electrophoresis, assessment of DNA purity, MTHFR C 677T gene mutation detection by PCR-RFLP method. Statistical analysis: Carried out by web based online SPSS tool. Results: The frequency of C677T genotype showed homozygous wild type CC (80%), heterozygous CT type (13.3%) and homozygous mutation TT type (6.67%) observed in males. Similarly from female’s homozygous wild type CC (86.6%), heterozygous type (13.3%), and homozygous type mutations TT (0%) was recorded. In couple control groups, we observed homozygous wild type CC (86.6%), heterozygous CT type (13.3%) and homozygous type mutations TT type (0%). Conclusion: We noticed a high frequency of MTHFR specifically T allele associated with paternal side.Therefore, the present study indicated the impact of paternal gene polymorphism of MTHFR C677T on screening in couples with recurrent pregnancy loss. PMID:25859445

  17. Methylenetetrahydrofolate reductase (MTHFR-677 and MTHFR-1298) genotypes and haplotypes and plasma homocysteine levels in patients with occlusive artery disease and deep venous thrombosis.

    PubMed

    Spiroski, Igor; Kedev, Sashko; Antov, Slobodan; Arsov, Todor; Krstevska, Marija; Dzhekova-Stojkova, Sloboda; Bosilkova, Gordana; Kostovska, Stojanka; Trajkov, Dejan; Petlichkovski, Aleksandar; Strezova, Ana; Efinska-Mladenovska, Olivija; Spiroski, Mirko

    2008-01-01

    The aim was to investigate different genotypes and haplotypes of methylenetetrahydrofolate reductase (MTHFR-677, -1298) and plasma concentration of total homocysteine (tHcy) in Macedonian patients with occlusive artery disease (OAD) and deep venous thrombosis (DVT). Investigated groups consists of 80 healthy, 74 patients with OAD, and 63 patients with DVT. Plasma tHcy was measured with Microplate Enzyme Immunoassay. Identification of MTHFR genotypes and haplotypes was done with CVD StripAssay. The probability level (P-value) was evaluated by the Student's t-test. Plasma concentration of tHcy in CC and CT genotypes of MTHFR C677T was significantly increased in patients with OAD and in patients with DVT. Plasma concentration of tHcy in AC genotype of MTHFR A1298C was increased in patients with OAD and in patients with DVT. Plasma concentration of tHcy was significantly increased in AA genotype of patients with OAD, but not in patients with DVT. We found a significant increase of plasma tHcy in patients with OAD in comparison with healthy respondents for normal:heterozygote (CC:AC), heterozygote:normal (CT:AA), and heterozygote:heterozygote (CT:AC) haplotypes. Plasma concentration of tHcy in patients with DVT in comparison with healthy respondents was significantly increased for normal:normal (CC:AA), normal heterozygote (CC:AC), and heterozygote:heterozygote (CT:AC) haplotypes. We conclude that MTHFR C677T and MTHFR A1289C genotypes and haplotypes are connected with tHcy plasma levels in Macedonian patients with OAD and DVT. PMID:18800176

  18. Anxiety and Methylenetetrahydrofolate Reductase Mutation Treated With S-Adenosyl Methionine and Methylated B Vitamins.

    PubMed

    Anderson, Shanna; Panka, Jacob; Rakobitsch, Robin; Tyre, Kaitlin; Pulliam, Kerry

    2016-04-01

    This case report highlights challenges faced in the clinical management of patients with methylenetetrahydrofolate reductase (MTHFR) gene mutations and the importance of precise dosage when recommending methylated B vitamins to compensate for deficiencies caused by the polymorphism or symptoms related to the polymorphism. It also underscores the importance of obtaining ongoing objective assessments of anxiety (eg, Patient Reported Outcomes Measurement Information System, or PROMIS) to help gauge patient response. PMID:27330489

  19. Comparison of the frequency of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in depressed versus nondepressed patients.

    PubMed

    Lizer, Mitsi H; Bogdan, Renee L; Kidd, Robert S

    2011-11-01

    Numerous studies have found an association between low serum folate levels and incidence of depression. Folic acid supplementation has been successfully used as an adjunct to treat depression in these patients. However, some individuals have a genetic deficiency in the methylene tetrahydrofolate reductase (MTHFR) gene that limits conversion of folic acid to its biologically active form, L-methylfolate. Several studies have identified a higher frequency of genetic variations in the MTHFR gene in depressed patients than in nondepressed controls. This study evaluated the frequency of the most common genetic variation MTHFR C667T in a group of depressed U.S. Caucasians and compared results with those of a control group of nondepressed U.S. Caucasians. Subjects were recruited from a psychiatric practice, an ambulatory care clinic, and the community. Informed consent and a cheek swab sample were obtained from each subject for analysis using real-time polymerase chain reaction (PCR). Allele and genotype frequencies were compared using Pearson X2 analysis. Complete data were obtained for 156 subjects. No significant differences were found in frequency of the MTHFR C667T T allele (0.415 vs 0.365; p=0.408) or the MTHFR C667T TT genotype (20.7% vs 17.6%; p=0.619) between the depressed and non-depressed controls, respectively. Therefore, use of L-methylfolate without an additional indication of need does not appear to be warranted in this group of U.S. Caucasians. Some patients may benefit from L-methylfolate, but an evidence-based approach, such as MTHFR genotyping, should be used to identify these specific patients. Additional research is also needed to confirm the benefit of L-methylfolate in specific patient populations (e.g., MTHFR TT genotype). PMID:22108397

  20. Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms resulting in suboptimal oocyte maturation: a discussion of folate status, neural tube defects, schizophrenia, and vasculopathy

    PubMed Central

    Jongbloet, Piet Hein; Verbeek, André LM; den Heijer, Martin; Roeleveld, Nel

    2008-01-01

    Several conditions apparent at birth, e.g., neural tube defects (NTDs) and cardiac anomalies, are associated with polymorphisms in folate-related genes, such as the 677C → T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene. Similar associations have been established for several constitutional chronic diseases in adulthood, such as schizophrenia, cardiovascular diseases, dementia, and even neoplasias in different organ systems. This spectrum of developmental anomalies and constitutional diseases may be linked to high-risk conceptions related to preovulatory overripeness ovopathy (PrOO). Some developmental anomalies, such as NTDs, are to a large extent prevented by supplementation of folic acid before conception, but supplementation does not seem to prevent cardiovascular disease or cognitive decline. These diverging results can be elucidated by introduction of the PrOO concept, as MTHFR polymorphisms and inherent low folate levels induce both non-optimal maturation of the oocyte and unsuccessful DNA methylation and demethylation, i.e. epigenetic mutations. The PrOO concept is testable and predicts in a random population the following: (1) female carriers of specific genetic MTHFR variants exhibit more ovulatory disturbances and inherent subfecundity traits, (2) descendents from a carrier mother, when compared with those from a wild-type mother, are more frequently conceived in PrOO high-risk conditions and, thus, (3) disadvantaged in life expectancy. If so, some MTHFR polymorphisms represent a novel, genetically determined, PrOO high-risk conception category comparable to those which are environmentally and behaviorly influenced. These high-risk conditions may cause developmental anomalies and defective epigenetic reprogramming in progeny. The interaction between genetic and environmental factors is a plausible mechanism of multifactorial inheritance. PMID:18616826

  1. Seven novel mutations at the 5,10-methylenetetrahydrofolate reductase locus

    SciTech Connect

    Goyette, P.; Frosst, P.; Rosenblatt, D.S.; Rozen, R.

    1994-09-01

    5,10-methylenetetrahydrofolate reductase (MTHFR), a flavoprotein, catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a cofactor for methionine synthase in the methylation of homocysteine to methionine. Severe MTHFR deficiency, which causes homocysteinemia, is an autosomal recessive disorder with variable clinical features; developmental delay, perinatal death, mental retardation and asymptomatic individuals have been observed. A milder deficiency has been reported in patients with cardiovascular disease. We have recently described the isolation of a cDNA for MTHFR and the identification of 2 mutations in patients with severe MTHFR deficiency. We report here the characterization of 7 additional mutations at this locus: 5 missense mutations and 2 splicing mutations. Mutation analysis was performed by SSCP on PCR products generated either from reverse transcription-PCR of patients` total fibroblast RNA or from PCR of patients` genomic DNA. The 5 missense mutations are as follows: 1 Arg to Cys substitution in a hydrophilic segment proposed to be the hinge region that connects the catalytic and regulatory domains, 2 different Arg to Cys substitutions in 2 patients whose enzymatic thermolability is responsive to FAD, 1 Thr to Met substitution affecting an evolutionarily-conserved residue and a Pro to Leu substitution. The 2 splicing mutations affect the 5{prime} splice site and the 3{prime} splice site of 2 introns, respectively. The 5{prime} splice site mutation generates a 57 bp in-frame deletion of the RNA through the utilization of a cryptic 5{prime} splice site within the coding sequence. The identification of 9 mutations at this locus has allowed us to make preliminary correlations between genotype and phenotype and to contribute to a structure:function analysis of the enzyme.

  2. A Meta-Analysis of Association between Methylenetetrahydrofolate Reductase Gene (MTHFR) 677C/T Polymorphism and Diabetic Retinopathy

    PubMed Central

    Luo, Shasha; Wang, Furu; Shi, Chao; Wu, Zhifeng

    2016-01-01

    Aims: To shed light on the conflicting findings of the association between the methylenetetrahydrofolate reductase gene (MTHFR) 677C/T polymorphism and the risk of diabetic retinopathy (DR), a meta-analysis was conducted. Methods: A predefined search was performed on 1747 DR cases and 3146 controls from 18 published studies by searching electronic databases and reference lists of relevant articles. A random-effects or fixed-effects model was used to estimate the sizes of overall and stratification effects of the MTHFR 677C/T polymorphism on the risk of DR, as appropriate. Results: Risks were evaluated by odds ratios (OR) with 95% confidence intervals (95% CI). We found a significant association between the MTHFR 677C/T polymorphism and the risk of DR for each genetic model (recessive model: OR = 1.67; 95% CI: 1.19–2.40 and dominant model: OR = 1.71; 95% CI: 1.28–2.28; respectively). In stratified analysis; we further found that the Asian group with both types of diabetes mellitus (DM) showed a significant association with genetic models (recessive model: OR = 2.16; 95% CI: 1.75–2.60 and dominant model: OR = 1.98; 95% CI: 1.42–2.76; respectively). Conclusions: Our study suggested that the MTHFR 677C/T polymorphism may contribute to DR development, especially in Asian populations. Prospective and additional genome-wide association studies (GWAS) are needed to clarify the real role of the MTHFR gene in determining susceptibility to DR. PMID:27517946

  3. Methylenetetrahydrofolate reductase (MTHFR) 677C>T gene polymorphism as a possible factor for reducing clinical severity of psoriasis

    PubMed Central

    Karabacak, Ercan; Aydin, Ersin; Ozcan, Omer; Dogan, Bilal; Gultepe, Mustafa; Cosar, Alpaslan; Muftuoglu, Tuba

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is a crucial enzyme in homocysteine/methionine metabolism. It catalysis the formation of 5-methyltetrahydrofolate (5-methyl-THF), which is the methyl donor for synthesis of methionine from homocysteine (Hcy). Decreases in folate consumption due to MTHFR polymorphism may affect production rate of keratinocytes of which had faster reproduction rates with a continuous DNA turnover and this may affect the clinical picture of psoriasis. This study aimed to investigate correlation of C677T polymorphisms in the MTHFR gene with severity of psoriasis and to evaluate the status of plasma Hcy, folate and vitamin B12 levels in patient with chronic plaque psoriasis. The study included 60 patients with chronic plaque psoriasis. The C677T polymorphisms were genotyped using PCR (Qiagen). Psoriasis Area and Severity Index (PASI) score below 7 was defined as mild, between 7 and 12 as moderate, and above 12 as severe disease. There was a significant difference between the severity of disease classification (p<0.05) with respect to the C677T polymorphism in the MTHFR gene. Severe involvement (PASI score >12) was observed in 38.46% of wild type (CC), but only 12.50% of homozygote (TT) and 7.69% of heterozygote (CT) patients. Significant differences between gene polymorphism and Hcy levels were noted in TT and CT genotypes respectively (p=0.025 and p=0.040). Plasma Hcy, folate and vitamin B12 levels were not correlated with the PASI score. Our data indicate a possible correlation of MTHFR polymorphism with severity of psoriasis. PMID:24753765

  4. Altered protein phosphatase 2A methylation and Tau phosphorylation in the young and aged brain of methylenetetrahydrofolate reductase (MTHFR) deficient mice.

    PubMed

    Sontag, Jean-Marie; Wasek, Brandi; Taleski, Goce; Smith, Josephine; Arning, Erland; Sontag, Estelle; Bottiglieri, Teodoro

    2014-01-01

    Common functional polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, a key enzyme in folate and homocysteine metabolism, influence risk for a variety of complex disorders, including developmental, vascular, and neurological diseases. MTHFR deficiency is associated with elevation of homocysteine levels and alterations in the methylation cycle. Here, using young and aged Mthfr knockout mouse models, we show that mild MTHFR deficiency can lead to brain-region specific impairment of the methylation of Ser/Thr protein phosphatase 2A (PP2A). Relative to wild-type controls, decreased expression levels of PP2A and leucine carboxyl methyltransferase (LCMT1) were primarily observed in the hippocampus and cerebellum, and to a lesser extent in the cortex of young null Mthfr (-/-) and aged heterozygous Mthfr (+/-) mice. A marked down regulation of LCMT1 correlated with the loss of PP2A/Bα holoenzymes. Dietary folate deficiency significantly decreased LCMT1, methylated PP2A and PP2A/Bα levels in all brain regions examined from aged Mthfr (+/+) mice, and further exacerbated the regional effects of MTHFR deficiency in aged Mthfr (+/-) mice. In turn, the down regulation of PP2A/Bα was associated with enhanced phosphorylation of Tau, a neuropathological hallmark of Alzheimer's disease (AD). Our findings identify hypomethylation of PP2A enzymes, which are major CNS phosphatases, as a novel mechanism by which MTHFR deficiency and Mthfr gene-diet interactions could lead to disruption of neuronal homeostasis, and increase the risk for a variety of neuropsychiatric disorders, including age-related diseases like sporadic AD. PMID:25202269

  5. Association study of methylenetetrahydrofolate reductase A1298C mutation with cerebral venous thrombosis risk in an Iranian population

    PubMed Central

    Habib, Ghaznavi; Zahra, Soheili; Shahram, Samiei; Soltanpour, Mohammad Soleiman

    2015-01-01

    Background: Cerebral venous thrombosis (CVT) is an uncommon condition characterized by severe clinical manifestations and high mortality rate. There is limited data on the role of methylenetetrahydrofolate reductase (MTHFR) A1298C mutation as a risk factor for CVT development in Iranians. Aim: The aim was to investigate a possible association between fasting plasma homocysteine (Hcy) levels, MTHFR A1298C mutation, and CVT in Iranian population. Materials and Methods: The study population consisted of 50 patients with a diagnosis of CVT (20–63 years old) and 75 healthy subjects (18–65 years old) as control. Genotyping of the MTHFR A1298C mutation and Hcy measurement was carried out by polymerase chain reaction-restriction fragment length polymorphism technique and enzyme immunoassay method, respectively. Results: Fasting plasma total Hcy levels were significantly higher in CVT patients than controls (P = 0.015). No significant differences were observed in the MTHFR A1298C genotypes frequency between CVT patients and controls (P > 0.05). The frequency of the 1298C allele was 36% and 37.5% in CVT patients and controls, respectively and did not differ significantly between the two groups (P = 0.16). Conclusions: Our study demonstrated that MTHFR A1298Cmutation is not a significant risk factor for CVT. PMID:26539365

  6. Altered protein phosphatase 2A methylation and Tau phosphorylation in the young and aged brain of methylenetetrahydrofolate reductase (MTHFR) deficient mice

    PubMed Central

    Sontag, Jean-Marie; Wasek, Brandi; Taleski, Goce; Smith, Josephine; Arning, Erland; Sontag, Estelle; Bottiglieri, Teodoro

    2014-01-01

    Common functional polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, a key enzyme in folate and homocysteine metabolism, influence risk for a variety of complex disorders, including developmental, vascular, and neurological diseases. MTHFR deficiency is associated with elevation of homocysteine levels and alterations in the methylation cycle. Here, using young and aged Mthfr knockout mouse models, we show that mild MTHFR deficiency can lead to brain-region specific impairment of the methylation of Ser/Thr protein phosphatase 2A (PP2A). Relative to wild-type controls, decreased expression levels of PP2A and leucine carboxyl methyltransferase (LCMT1) were primarily observed in the hippocampus and cerebellum, and to a lesser extent in the cortex of young null Mthfr−/− and aged heterozygous Mthfr+/− mice. A marked down regulation of LCMT1 correlated with the loss of PP2A/Bα holoenzymes. Dietary folate deficiency significantly decreased LCMT1, methylated PP2A and PP2A/Bα levels in all brain regions examined from aged Mthfr+/+ mice, and further exacerbated the regional effects of MTHFR deficiency in aged Mthfr+/− mice. In turn, the down regulation of PP2A/Bα was associated with enhanced phosphorylation of Tau, a neuropathological hallmark of Alzheimer’s disease (AD). Our findings identify hypomethylation of PP2A enzymes, which are major CNS phosphatases, as a novel mechanism by which MTHFR deficiency and Mthfr gene-diet interactions could lead to disruption of neuronal homeostasis, and increase the risk for a variety of neuropsychiatric disorders, including age-related diseases like sporadic AD. PMID:25202269

  7. Association between Methylenetetrahydrofolate Reductase (MTHFR) Gene Polymorphisms and Susceptibility to Childhood Acute Lymphoblastic Leukemia in an Iranian Population

    PubMed Central

    Bahari, Gholamreza; Hashemi, Mohammad; Naderi, Majid; Taheri, Mohsen

    2016-01-01

    Background: The present study was aimed to examine the possible association between methylene tetrahydrofolate reductase (MTHFR) gene polymorphisms and childhood acute lymphoblastic leukemia (ALL) in a sample of Iranian population. Subjects and Methods: A total of 220 subjects including 100 children diagnosed with ALL and 120 healthy children participated in the case-control study. The single nucleotide polymorphisms (SNPs) of MTHFR were determined by ARMS-PCR or PCR-RFLP method. Results: Our investigation revealed that rs13306561 both TC and TC + CC genotypes decreased the risk of ALL compared to TT genotype (OR=0.32, 95%CI=0.15-0.68, p=0.002 and OR=0.35, 95%CI=0.17-0.70, p=0.003, respectively). In addition, the rs13306561 C allele decreased the risk of ALL in comparison with T allele (OR=0.42, 95% CI=0.22-0.78, P=0.005). MTHFR rs1801131 (A1298C) polymorphism showed that the AC heterozygous genotype decreased the risk of ALL in comparison with AA homozygous genotype (OR=0.43, 95%CI=0.21-0.90, p=0.037). Neither the overall Chi-square comparison of cases and control subjects (𝜒2=5.54, p=0.063) nor the logistic regression analysis showed significant association between C677T polymorphism and ALL (OR=1.25, 95% CI=0.69-2.23, p=0.552; CT vs. CC). Conclusion: The current investigation findings showed that MTHFR rs1801131 and rs13306561 polymorphisms decreased the risk of ALL in the population which has been studied. Further studies with larger sample sizes and different ethnicities are required to validate our findings. PMID:27489588

  8. Association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism with ischemic stroke in the Eastern Chinese Han population.

    PubMed

    Lv, Q-Q; Lu, J; Sun, H; Zhang, J-S

    2015-01-01

    The association between the MTHFR genetic polymorphism and ischemic stroke has been reported by a number of investigators. However, the results have been controversial and conflicting. The aim of this study was to explore the association between the MTHFR variants C677T and A1298C and the risk of ischemic stroke in an Eastern Chinese Han population. A total of 199 patients with ischemic stroke and 241 controls were recruited. Genotyping of the MTHFR C677T and A1298C polymorphisms was carried out using the Taqman 7900HT Sequence Detection System. The overall estimates (odds ratio: OR) for the allele (C) and genotype (AC+CC) of the A1298C polymorphism were 1.57 [95% confidence interval (CI) = 1.16-2.10], and 2.36 (95%CI = 1.39-4.00), respectively, establishing significant association of the MTHFR A1298C polymorphism with ischemic stroke. In contrast, there were no statistically significant differences compared to controls between MTHFR C677T polymorphic variants in the association ischemic stroke risk. Furthermore, haplotype-based analysis demonstrated that compared with the C-677-A-1298 haplotype, the C-677-C-1298 and T-677-C-1298 haplotypes showed significant increased risk of ischemic stroke (OR = 1.56; 95%CI = 1.07- 2.2; P = 0.02; OR = 1.76; 95%CI = 1.17-2.65; P < 0.01, respectively). We concluded that the A1298C polymorphism and the haplotypes C-677-C-1298 and T-677-C-1298 in MTHFR might modulate the risk of ischemic stroke in the Eastern Chinese Han population. PMID:25966188

  9. Two Mutations in the Caprine MTHFR 3'UTR Regulated by MicroRNAs Are Associated with Milk Production Traits

    PubMed Central

    Song, Yuxuan; Gao, Teyang; Lei, Yingnan; Cao, Binyun

    2015-01-01

    Background 5,10-Methylenetetrahydrofolate reductase (MTHFR) plays a central role in folate metabolism by irreversibly converting 5,10-methylenetetrahydrofolate to 5-methylenetetrahydrofolate, a predominant circulating form of folate. Folate is reportedly important for milk protein synthesis, and MTHFR may be a key regulatory point of folate metabolism for milk protein synthesis in mammary epithelial cells. Prior to this study, polymorphisms of the MTHFR gene were not associated with milk production traits from a breeding perspective. Single nucleotide polymorphisms (SNPs) at microRNA (miRNA) binding sites (miR-SNPs) can affect gene expression. This study aimed to identify the effects of miR-SNPs (g.2244A>G and g.2264A>G) in the caprine MTHFR 3' UTR on the milk production traits of dairy goats. Results Guanzhong dairy (GD, n = 325) goats were used to detect SNPs in the caprine MTHFR 3' UTR by DNA sequencing. Two novel SNPs (g.2244A>G and g.2264A>G) were identified in the said region. The homozygous haplotype A-G of the SNPs g.2244A>G and g.2264A>G was significantly associated with milk yield and milk protein levels in GD goats (P < 0.05). Functional assays indicated that the MTHFR 2244 A → G substitution could increase the binding activity of hsa-miR-1266 with the MTHFR 3' UTR. The MTHFR 2264 A → G substitution could decrease the binding activity of hsa-miR-616 with the MTHFR 3' UTR. In addition, we observed a significant increase in the MTHFR mRNA levels of homozygous haplotype A-G carriers relative to those of homozygous haplotype G-A carriers. These results indicated that both SNPs altered the MTHFR mRNA levels. These altered levels of MTHFR mRNA may account for the association of SNPs with milk production traits. Conclusions This study is the first to report that the g.2244A>G and g.2264A>G polymorphisms were associated with milk production traits in GD goats. Further investigations should explore the underlying miRNA-mediated mechanisms that are modified by

  10. MTHFR 677C/T and 1298A/C mutations and non-alcoholic fatty liver disease.

    PubMed

    Kasapoglu, Benan; Turkay, Cansel; Yalcin, Kadir Serkan; Kosar, Ali; Bozkurt, Alper

    2015-06-01

    Common genetic mutations encountered in folate metabolism may result in increased homocysteine (Hcy) levels. It has been reported that increased serum Hcy levels may affect the intracellular fat metabolism and may cause enhanced fatty infiltration in the liver resulting in non-alcoholic fatty liver disease (NAFLD). In total, 150 patients diagnosed with FLD by ultrasound examination and 136 healthy control patients that do not have any fatty infiltration in the liver were included in the study. Patients were grouped as mild (n = 88), moderate (n = 38) or severe (n = 24) according to the stage of fatty liver in ultrasound. Serum liver function tests, Hcy, folic acid and vitamin B12 levels of the patients were studied. The genetic MTHFR C677T and A1298C polymorphisms of the patients were also evaluated. Although there was no significant difference in vitamin B12 and folic acid levels, in the severe group, Hcy levels were significantly higher than that of control and mild groups (p<0.001). By contrast, there was no significant difference in heterozygote MTHFR 677C/T and 1298A/C mutations, both MTHFR 677C/T and MTHFR 1298A/C mutations were more common in NAFLD groups compared with the control patients (p<0.001). We have determined increased Hcy levels and increased prevalence of homozygote MTHFR 677C/T and MTHFR 1298A/C mutations in patients with NAFLD compared with healthy controls. Larger studies are warranted to clarify the etiological role of the MTHFR mutations and Hcy levels in FLD. PMID:26031974

  11. Factor V Leiden, Prothrombin and MTHFR Mutation in Patients with Preeclamsia, Intrauterine Growth Restriction and Placental Abruption

    PubMed Central

    Livrinova, Vesna; Lega, Marija Hadzi; Dimcheva, Anita Hristova; Samardziski, Igor; Isjanovska, Rozalinda

    2015-01-01

    BACKGROUND: Factor V Leiden, Prothrombin and MTHFR gene mutation, could have an influence in pregnancy with adverse outcome Preeclamsia, IUGR and Placental abruption. AIM: The aim of this study is to investigate the presence of above mentioned inherited thrombophilias and its statistical significance, distribution among the complicated and normal pregnancy, and relative risk for carrier of mutation to develop preeclampsia, IUGR and placental abruption. MATERIAL AND METHODS: Prospective cohort study is implemented at University Clinic for Obstetric and Gynecology in Skopje, Republic of Macedonia. The study included 109 delivered patients: 40 with preeclapmsia, 22 with IUGR, 17 with placental abruption and 30 as control group with normal pregnancy. The amount of 3 ml venous blood has been used for detection of these point mutations using ThromboStrip -Opegen, QIAGEN kit manufactured for thrombotic risk. RESULTS: The highest frequency was found: in the group with preeclampsia 35% were MTHFR homozygous, IUGR -MTHFR heterozygous 45%, Placental abruption- 52.9% MTHFR heterozygous, and in the control group without thrombophilia 56.7%. There were combined thrombophilia in 3 patients. There aren`t statistical significance in presence of thrombophilia among groups (p > 0.05). Statistical significance (p < 0.05) was found between carriers of MTHFR homozygous in preeclampsia and group with placental abruption and control group. Relative risk in IUGR group for MTHFR homozygous was 5.54 (1.37mutation MTHFR homozygous could increase the risk for development of IUGR and mutation of Factor V Leiden for placental abruption. Further investigations with more patients are warranted.

  12. TGFBR2 mutation and MTHFR-C677T polymorphism in a Mexican mestizo population with cervico-cerebral artery dissection.

    PubMed

    Ruiz-Franco, Angélica; Barboza, Miguel A; Jara-Prado, Aurelio; Canizales-Quinteros, Samuel; Leon-Mimila, Paola; Arguelles-Morales, Nayelli; Vargas-González, Juan-Camilo; Quiroz-Compean, Alejandro; Arauz, Antonio

    2016-06-01

    Spontaneous cervico-cerebral artery dissection (CCAD) is a common condition found among young patients with ischemic stroke. We examined the possible association between the polymorphism of methylenetetrahydrofolate reductase (MTHFR)-C677T and the gene mutation in transforming growth factor beta receptor II (TGFBR2) in a cohort of CCAD patients. One-hundred CCAD cases (65 males; mean age: 38.08 ± 10.68 years) and 100 matching controls were included. Ancestry informative markers (AIMs) were used to increase internal validity of the genetic analysis. Genotypes of the C677T polymorphism in the MTHFR gene were determined by polymerase chain reaction and restriction fragment length polymorphism; direct sequencing was used for a mutation analysis of the TGFBR2 gene. Associations were evaluated using a multivariate statistics, and Hardy-Weinberg equilibrium was analyzed. We also incorporated our data into a meta-analysis of the MTHFR-C677T. Sixty-three patients presented with vertebral and 37 with carotid artery dissection. Ancestry markers found a call rate on each over 95 %. All AIMs did not deviate from Hardy-Weinberg equilibrium (p > 0.05). The homozygous TT genotype was more frequent in cases (OR 2.04, CI 95 % 1.53-2.72, p = 0.005), whereas no significant difference was found on heterozygous CT genotype. TGFBR2 mutation was not present in our samples. In the meta-analysis of MTHFR/C677T variant, a total 613 cases and 1547 controls were analyzed; we found a moderate association for the recessive model genotype (OR 2.04, CI 95 % 1.53-2.72; p = 0.342; Z = 4.83; I (2) = 11.3). This study supports a positive association between the MTHFR-C677T polymorphism and genetically confirmed Mexican mestizo CCAD patients. PMID:27017342

  13. Portal Vein Thrombosis in a Preterm Newborn with Mutation of the MTHFR and PAI-1 Genes and Sepsis by Candida parapsilosis.

    PubMed

    Giuffrè, Mario; Verso, Clelia Lo; Serra, Gregorio; Moceri, Giovanni; Cimador, Marcello; Corsello, Giovanni

    2016-09-01

    Objective This report discusses the role of both congenital and acquired risk factors in the pathogenesis of portal vein thrombosis (PVT). Study Design We describe the clinical management and treatment of PVT in a preterm newborn with a homozygous mutation of the methylenetetrahydrofolate reductase (MTHFR) and plasminogen activator inhibitor-1 (PAI-1) genes and sepsis by Candida parapsilosis. Results Although literature data suggest a minor role of genetic factors in thrombophilia in the case of only one mutation, we hypothesize that combined thrombophilic genetic defects may have a cumulative effect and significantly increase the thrombotic risk. Conclusion It could be appropriate to include more detailed analyses of procoagulant and fibrinolytic factors in the diagnostic workup of neonatal thrombosis, also through the investigation of genetic polymorphisms. The anticoagulant therapy and the removal of concurrent risk factors remain basic steps for the adequate management and prevention of complications. PMID:27603544

  14. Association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and susceptibility to Graves' ophthalmopathy.

    PubMed

    Lee, Jae Yeun; Kim, Nam Keun; Cho, Yong Wook; Lew, Helen

    2016-09-01

    The pathogenesis of Graves' ophthalmopathy (GO) remains to be entirely elucidated. The present study aimed to determine the association between phenotypic expression of the MTHFR gene and susceptibility to GO in patients with Graves' disease (GD). A prospective case‑controlled study was conducted with 122 patients with GD and GO (n=72) or without GO (n=50) and 100 healthy controls in South Korea. Patient history, including smoking, nutritional status, thyroid function and antithyroid antibodies were investigated and clinical activity score, VISA classification (which includes vision, inflammation, strabismus and appearance/exposure) and orbit computed tomography were evaluated. Fasting plasma total homocysteine (tHcy) concentration was measured, and genotype analysis of the MTHFR gene was conducted. The TT homozygous genotype was associated with a two‑fold increased risk of GO [adjusted odds ratio (AOR), 2.19; 95% confidence interval (CI), 0.78‑6.14]. However, this result was not significant. The TT genotype significantly increased the risk of GO compared with that in healthy controls (AOR, 2.92; 95% CI, 1.11‑7.65). The MTHFR 677CT/1298AA genotype decreased the risk of GO in patients with GD (AOR, 0.26; 95% CI, 0.08‑0.91). tHcy levels in patients with GD without GO were significantly higher than in patients with GO, however, they were within the normal limit. The current study identified an association between MTHFR polymorphisms and GO. These results will aid understanding of the pathogenesis of GO and facilitate development of genetic therapeutic strategies. PMID:27430300

  15. Myocardial infarction in a newborn heterozygous for the MTHFR C677T mutation.

    PubMed

    Clark, Amy B; Stokes, Theophil A; Krous, Henry F; Carbine, Douglas N

    2012-01-01

    Neonatal myocardial infarction secondary to congenital heart disease, anomalous coronary artery anatomy, thromboembolism, coagulopathy, birth asphyxia, and unknown causes has been previously reported. We now report an infant who suffered a massive myocardial infarction during birth, requiring extensive resuscitation and aggressive management. A thrombus, the origin of which was not detected on autopsy, was found occluding the proximal left coronary artery several hours after birth. Genetic studies revealed a single copy variant of the MTHFR C677T mutation that we speculate may have predisposed the infant to coronary thrombosis. PMID:22339112

  16. Impact of new mutations in the methylenetetrahydrofolate reductase gene assessed on biochemical phenotypes: a familial study.

    PubMed

    Tonetti, C; Amiel, J; Munnich, A; Zittoun, J

    2001-12-01

    Methylenetetrahydrofolate reductase (MTHFR) deficiency was identified in two out of four children born from nonconsanguineous parents. One of the affected children exhibited some clinical findings suggesting cystathionine beta-synthase deficiency; MTHFR activity was extremely reduced. In addition, hyperhomocysteinaemia, hypomethioninaemia, low total folate, especially methylfolate in red blood cells, and a reduced methylfolate/total folate ratio were found. Two mutations not yet reported, one on exon 1 of the gene changing an arginine to stop codon and one other on exon 9 changing an arginine to tryptophan were identified in both children in the compound heterozygous state associated with a common polymorphism, 1298A>C, also in the heterozygous state. The mother, homozygous for the mutation on exon 9 and for the polymorphism 1298A>C on exon 7, was clinically and biochemically normal, with normal folate status, mainly methylfolate levels in red blood cells, although MTHFR activity was moderately decreased. The father, heterozygous for the transition arginine to stop codon and for the common polymorphism 677C>T on exon 4, exhibited major biochemical abnormalities, hyperhomocysteinaemia and low methylfolate levels in red blood cells, but was clinically normal. The unaffected children had a biochemical pattern close to that of their mother and were heterozygous for the mutation on exon 9 and also for the two common polymorphisms, 677C>T and 1298A>C. In the affected children, some biochemical abnormalities, including folate status, especially methylfolate levels, were improved with treatment combining methyltetrahydrofolic acid, hydroxocobalamin, pyridoxine and betaine; however, homocysteine concentrations remained high and methionine concentrations were lowered. The father was treated with folic acid, which partially improved biochemical abnormalities. The impact of these mutations is discussed. PMID:11916316

  17. High frequency of vitamin B12 deficiency in asymptomatic individuals homozygous to MTHFR C677T mutation is associated with endothelial dysfunction and homocysteinemia.

    PubMed

    Zittan, E; Preis, M; Asmir, I; Cassel, A; Lindenfeld, N; Alroy, S; Halon, D A; Lewis, B S; Shiran, A; Schliamser, J E; Flugelman, M Y

    2007-07-01

    The aim of this study was to examine the association of homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T mutation and vitamin B12 deficiency in 360 asymptomatic individuals and to investigate forearm endothelial function in C677T homozygotes. MTHFR C677T mutation and levels of vitamin B12, folic acid, and homocysteine were measured in study participants. Frequency of homozygosity for the C677T mutation was 67/360 (18.6%). Homocysteine levels were elevated in homozygous compared with heterozygous subjects or those without the mutation (20.6 +/- 18.8 vs. 9.4 +/- 3.2 mumol/l; P < 0.0001). The number of subjects with vitamin B12 deficiency (<150 pmol/l) was significantly higher among the homozygote than the heterozygote subjects or subjects without mutation [20/67 (29.8%) vs. 27/293 (9.2%); P < 0.0001]. Homozygote subjects had 4.2 times higher probability of having B12 deficiency (95% confidence interval = 2.1-8.3). Forearm endothelial function was assessed in 33 homozygote and 12 control subjects. Abnormal endothelial function was observed in homozygous subjects and was worse in homozygote subjects with vitamin B12 deficiency. Endothelial function was normalized after B12 and folic acid treatment. We found that homozygosity for the C677T mutation is strongly associated with B12 deficiency. Coexistence of homozygosity for the C677T mutation and B12 deficiency is associated with endothelial dysfunction and can be corrected with vitamin B12 and folic acid treatment. PMID:17449548

  18. Methylenetetrahydrofolate Reductase C677T: Hypoplastic Left Heart and Thrombosis.

    PubMed

    Spronk, Kimberly J; Olivero, Anthony D; Haw, Marcus P; Vettukattil, Joseph J

    2015-10-01

    The incidence of congenital heart defects is higher in infants with mutation of methylenetetrahydrofolate reductase (MTHFR) gene. The MTHFR C677T gene decreases the bioavailability of folate and increases plasma homocysteine, a risk factor for thrombosis. There have been no reported cases in the literature on the clinical implications of this procoagulable state in the setting of cyanotic heart disease, which itself has prothrombotic predisposition. Two patients with hypoplastic left heart syndrome developed postoperative thrombotic complications, both were homozygous for MTHFR C677T. We present these cases and highlight the implications of MTHFR mutation in the management of complex congenital heart disease. PMID:26467879

  19. Nonarteritic anterior ischemic optic neuropathy: associations with homozygosity for the C677T methylenetetrahydrofolate reductase mutation.

    PubMed

    Glueck, Charles J; Wang, Ping; Bell, Howard; Rangaraj, Venkat; Goldenberg, Naila

    2004-03-01

    The association between nonarteritic anterior ischemic optic neuropathy (NAION) and coagulation disorders was prospectively assessed at least 3 months after the occurrence of ocular vascular events in 12 white patients in an outpatient clinical research center. Two community-based ophthalmologists evaluated the 12 NAION patients in the consecutive order of their referral. Polymerase chain reaction-complementary DNA assays of gene mutations associated with coagulation disorders and serologic coagulation measurements in study patients were compared with those in 36 healthy, normal race-, sex-, and age-matched controls, with 3 controls matched for each case. Of the 12 patients, 4 men and 8 women (mean age 62 +/- 15 years, 3 of them 55 years or older), 8 had unilateral NAION (bilateral in 4). The 12 patients with NAION were more likely than controls to demonstrate homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T mutation (50% vs 11 %; Fisher's P =.009, with the likelihood of a type I error quite small, 0.9%). Our sample size had a power of 80% to detect this case-control difference in C677T MTHFR homozygosity at an alpha value of.05. Of the 12 NAION patients, 7 (58%) had at least 1 gene mutation in the C677T MTHFR, G1691A V Leiden, or G20210A prothrombin gene, compared with 5 of 36 controls (14%) (chi(2) = 9.48, P =. 002, with the likelihood of a type I error quite small, 0.2%). Our sample size had a power of 85% to detect this case-control difference at alpha =. 05. Of the 8 women with NAION, 5 (63%) first experienced the condition while taking hormone replacement therapy (n = 4) or during pregnancy (n = 1), with superposition of estrogen-induced thrombophilia on heritable thrombophilia and hypofibrinolysis. Confirmation of a causal relationship between coagulation disorders and NAION should facilitate its prevention and treatment and help protect against thrombi in other vascular beds. PMID:15007309

  20. Genetic Variation of Methylenetetrahydrofolate Reductase (MTHFR) and Thymidylate Synthase (TS) Genes Is Associated with Idiopathic Recurrent Implantation Failure.

    PubMed

    Choi, Youngsok; Kim, Jung Oh; Shim, Sung Han; Lee, Yubin; Kim, Ji Hyang; Jeon, Young Joo; Ko, Jung Jae; Lee, Woo Sik; Kim, Nam Keun

    2016-01-01

    The one-carbon metabolism pathway disorder was important role in successful pregnancy. The MTHFR and TS protein were crucial factor in one-carbon metabolism. To investigate the association between recurrent implantation failure (RIF) and enzymes in the one-carbon metabolism pathway. A total of 120 women diagnosed with RIF and 125 control subjects were genotyped for MTHFR 677C>T, 1298A>C, TSER 2R/3R and TS 1494del/ins by a polymerase chain reaction-restriction fragment length polymorphism assay. According to the gene-gene combination analysis, the MTHFR 677/MTHFR 1298 (TT/AA) and MTHFR 677/TS 1494 (TT/6bp6bp) genetic combinations were associated with relatively higher risks [adjusted odds ratio (AOR), 2.764; 95% CI, 1.065-7.174; P = 0.037 and AOR, 3.186; 95% CI, 1.241-8.178; P = 0.016] in RIF patients compared to the CC/AA (MTHFR 677/MTHFR 1298) and TT/6bp6bp (MTHFR 677/TS 1494) combinations, respectively. The results suggested that the combined MTHFR 677/MTHFR 1298 genotype might be associated with increased risk of RIF. To the best of our knowledge, this study is the first to elucidate the potential association of MTHFR, TS and TSER polymorphisms with RIF risk in Korean patients. PMID:27560137

  1. Genetic Variation of Methylenetetrahydrofolate Reductase (MTHFR) and Thymidylate Synthase (TS) Genes Is Associated with Idiopathic Recurrent Implantation Failure

    PubMed Central

    Shim, Sung Han; Lee, Yubin; Kim, Ji Hyang; Jeon, Young Joo; Ko, Jung Jae; Lee, Woo Sik; Kim, Nam Keun

    2016-01-01

    The one-carbon metabolism pathway disorder was important role in successful pregnancy. The MTHFR and TS protein were crucial factor in one-carbon metabolism. To investigate the association between recurrent implantation failure (RIF) and enzymes in the one-carbon metabolism pathway. A total of 120 women diagnosed with RIF and 125 control subjects were genotyped for MTHFR 677C>T, 1298A>C, TSER 2R/3R and TS 1494del/ins by a polymerase chain reaction-restriction fragment length polymorphism assay. According to the gene-gene combination analysis, the MTHFR 677/MTHFR 1298 (TT/AA) and MTHFR 677/TS 1494 (TT/6bp6bp) genetic combinations were associated with relatively higher risks [adjusted odds ratio (AOR), 2.764; 95% CI, 1.065–7.174; P = 0.037 and AOR, 3.186; 95% CI, 1.241–8.178; P = 0.016] in RIF patients compared to the CC/AA (MTHFR 677/MTHFR 1298) and TT/6bp6bp (MTHFR 677/TS 1494) combinations, respectively. The results suggested that the combined MTHFR 677/MTHFR 1298 genotype might be associated with increased risk of RIF. To the best of our knowledge, this study is the first to elucidate the potential association of MTHFR, TS and TSER polymorphisms with RIF risk in Korean patients. PMID:27560137

  2. Association of PHB 1630 C>T and MTHFR 677 C>T polymorphisms with breast and ovarian cancer risk in BRCA1/2 mutation carriers: results from a multicenter study

    PubMed Central

    Jakubowska, A; Rozkrut, D; Antoniou, A; Hamann, U; Scott, R J; McGuffog, L; Healy, S; Sinilnikova, O M; Rennert, G; Lejbkowicz, F; Flugelman, A; Andrulis, I L; Glendon, G; Ozcelik, H; Thomassen, M; Paligo, M; Aretini, P; Kantala, J; Aroer, B; von Wachenfeldt, A; Liljegren, A; Loman, N; Herbst, K; Kristoffersson, U; Rosenquist, R; Karlsson, P; Stenmark-Askmalm, M; Melin, B; Nathanson, K L; Domchek, S M; Byrski, T; Huzarski, T; Gronwald, J; Menkiszak, J; Cybulski, C; Serrano, P; Osorio, A; Cajal, T R; Tsitlaidou, M; Benítez, J; Gilbert, M; Rookus, M; Aalfs, C M; Kluijt, I; Boessenkool-Pape, J L; Meijers-Heijboer, H E J; Oosterwijk, J C; van Asperen, C J; Blok, M J; Nelen, M R; van den Ouweland, A M W; Seynaeve, C; van der Luijt, R B; Devilee, P; Easton, D F; Peock, S; Frost, D; Platte, R; Ellis, S D; Fineberg, E; Evans, D G; Lalloo, F; Eeles, R; Jacobs, C; Adlard, J; Davidson, R; Eccles, D; Cole, T; Cook, J; Godwin, A; Bove, B; Stoppa-Lyonnet, D; Caux-Moncoutier, V; Belotti, M; Tirapo, C; Mazoyer, S; Barjhoux, L; Boutry-Kryza, N; Pujol, P; Coupier, I; Peyrat, J-P; Vennin, P; Muller, D; Fricker, J-P; Venat-Bouvet, L; Johannsson, O Th; Isaacs, C; Schmutzler, R; Wappenschmidt, B; Meindl, A; Arnold, N; Varon-Mateeva, R; Niederacher, D; Sutter, C; Deissler, H; Preisler-Adams, S; Simard, J; Soucy, P; Durocher, F; Chenevix-Trench, G; Beesley, J; Chen, X; Rebbeck, T; Couch, F; Wang, X; Lindor, N; Fredericksen, Z; Pankratz, V S; Peterlongo, P; Bonanni, B; Fortuzzi, S; Peissel, B; Szabo, C; Mai, P L; Loud, J T; Lubinski, J

    2012-01-01

    Background: The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either directly or indirectly in maintaining genomic integrity. Methods: To evaluate the potential role of genetic variants within PHB and MTHFR in breast and ovarian cancer risk, 4102 BRCA1 and 2093 BRCA2 mutation carriers, and 6211 BRCA1 and 2902 BRCA2 carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2 (CIMBA) were genotyped for the PHB 1630 C>T (rs6917) polymorphism and the MTHFR 677 C>T (rs1801133) polymorphism, respectively. Results: There was no evidence of association between the PHB 1630 C>T and MTHFR 677 C>T polymorphisms with either disease for BRCA1 or BRCA2 mutation carriers when breast and ovarian cancer associations were evaluated separately. Analysis that evaluated associations for breast and ovarian cancer simultaneously showed some evidence that BRCA1 mutation carriers who had the rare homozygote genotype (TT) of the PHB 1630 C>T polymorphism were at increased risk of both breast and ovarian cancer (HR 1.50, 95%CI 1.10–2.04 and HR 2.16, 95%CI 1.24–3.76, respectively). However, there was no evidence of association under a multiplicative model for the effect of each minor allele. Conclusion: The PHB 1630TT genotype may modify breast and ovarian cancer risks in BRCA1 mutation carriers. This association need to be evaluated in larger series of BRCA1 mutation carriers. PMID:22669161

  3. Association of corticosteroids and factor V, prothrombin, and MTHFR gene mutations with avascular osteonecrosis in renal allograft recipients.

    PubMed

    Celik, A; Tekis, D; Saglam, F; Tunali, S; Kabakci, N; Ozaksoy, D; Manisali, M; Ozcan, M A; Meral, M; Gülay, H; Camsari, T

    2006-03-01

    The mechanism of posttransplantation avascular osteonecrosis (AVN) is controversial. Besides an increased bone marrow pressure due to reduced blood supply, enhanced coagulation has been considered. We investigated the associations of factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations as well as cumulative corticosteroid doses with AVN in renal allograft recipients. The records of 39 volunteer patients and 11 patients in whom osteonecrosis was previously identified were reviewed for cumulative corticosteroid dosages during the first year. All patients were screened for factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations by direct sequencing of genomic DNA. The cumulative corticosteroid dosages at 3, 6, and 12 months in the osteonecrotic group (5033.5 +/- 1565.3, 7164.9 +/- 2063.1, 8835.1 +/- 2216.8 mg) were significantly higher than in the control group (3629 +/- 1504.1, 4784.5 +/- 1568.7, 6322.4 +/- 1686.6 mg; P = .013, P = .001, P = .001, respectively). No significant difference in factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations was observed between the osteonecrotic and control groups (P > .05). In conclusion, an association between the first year (3, 6, and 12 month) cumulative corticosteroid dosages and AVN was demonstrated in renal transplant recipients. However, no correlation was determined between factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations and osteonecrosis. PMID:16549163

  4. Prevalence of factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations in 200 healthy Jordanians.

    PubMed

    Eid, Suhair S; Rihani, Ghada

    2004-01-01

    Thrombophilia is now considered a multi-causal condition, with interplay of acquired genetic risk factors. In order to estimate the frequency of the factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations in the Jordanian population, we screened 200 healthy Jordanian individuals. 40% were females. Mean age was 32.1 years for males and 30.0 years for female participants. A PCR method detected 15.0% factor V Leiden (87% heterozygous, 13% homozygous), 2% prothrombin G20210A (100% heterozygous), and 24% MTHFR C677T (67% heterozygous, 33% homozygous). We conclude that the prevalence of factor V Leiden and MTHFR C677T is elevated in this population of Jordanians. However the incidence of G20210A is relatively low. Quantification of these genetic thrombosis risk factors in various populations will contribute to a better understanding of the interaction of genetic and environmental risk factors. PMID:15559724

  5. Association of methylenetetrahytrofolate reductase (MTHFR) C677T and A1298C polymorphisms with the susceptibility of childhood acute lymphoblastic leukaemia (ALL) in Chinese population

    PubMed Central

    2014-01-01

    Background The aim of this study was to investigate the relationship between the polymorphisms of the methylenetetrahytrofolate reductase (MTHFR) gene and susceptibility to childhood acute lymphoblastic leukemia (ALL). Methods A case–control study was conducted among 98 children with ALL and 93 age- and sex- matched non-ALL controls. Genotyping of MTHFR C677T and A1298C polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The odds ratios (ORs) of MTHFR genotypes were used to assess the associations of these polymorphisms with childhood ALL susceptibility. Results No significant differences were observed for frequencies of the 677CC, 677CT and 677TT genotypes between patients and controls. Frequencies of the 1298AA, 1298 AC and 1298CC genotypes between the two groups were significantly different. The risk of ALL with the 1298C allele carriers (AC + CC) was elevated by 1.1 times compared with the AA genotype [OR = 2.100; 95% CI (1.149; 3.837); P = 0.015]. Conclusions The MTHFR A1298C polymorphism is associated with susceptibility to childhood ALL in the Chinese population. PMID:24476575

  6. Molecular genetic analysis in mild hyperhomocysteinemia: A common mutation in the methylenetetrahydrofolate reductase gene is a genetic risk factor for cardiovascular disease

    SciTech Connect

    Kluijtmans, L.A.J.; Heuvel, L.P.W.J. van den; Stevens, E.M.B.

    1996-01-01

    Mild hyperhomocysteinemia is an established risk factor for cardiovascular disease. Genetic aberrations in the cystathionine P-synthase (CBS) and methylenetetrahydrofolate reductase (MTHFR) genes may account for reduced enzyme activities and elevated plasma homocysteine levels. In 15 unrelated Dutch patients with homozygous CBS deficiency, we observed the 833T{yields}C (1278T) mutation in 50% of the alleles. Very recently, we identified a common mutation (677C{yields}T; A{yields}V) in the MTHFR gene, which, in homozygous state, is responsible for the thermolabile phenotype and which is associated with decreased specific MTHFR activity and elevated homocysteine levels. We screened 60 cardiovascular patients and 111 controls for these two mutations, to determine whether these mutations are risk factors for premature cardiovascular disease. Heterozygosity for the 833T{yields}C mutation in the CBS gene was observed in one individual of the control group but was absent in patients with premature cardiovascular disease. Homozygosity for the 677C-{yields}T mutation in the MTHFR gene was found in 9 (15%) of 60 cardiovascular patients and in only 6 ({approximately}5%) of 111 control individuals (odds ratio 3.1 [95% confidence interval 1.0-9.21]). Because of both the high prevalence of the 833T-{yields}C mutation among homozygotes for CBS deficiency and its absence in 60 cardiovascular patients, we may conclude that heterozygosity for CBS deficiency does not appear to be involved in premature cardiovascular disease. However, a frequent homozygous mutation in the MTHFR gene is associated with a threefold increase in risk for premature cardiovascular disease. 35 refs., 3 figs., 1 tab.

  7. The relationship between factor V Leiden, prothrombin G20210A, and MTHFR mutations and the first major thrombotic episode in polycythemia vera and essential thrombocythemia.

    PubMed

    Trifa, Adrian P; Cucuianu, Andrei; Popp, Radu A; Coadă, Camelia A; Costache, Roxana M; Militaru, Mariela S; Vesa, Ştefan C; Pop, Ioan V

    2014-02-01

    Arterial and venous thrombosis are the most frequent complications in patients with polycythemia vera and essential thrombocythemia. We sought to demonstrate a possible contribution of the factor V Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) 677 C > T and 1298 A > C mutations to the thrombotic risk in patients with polycythemia vera and essential thrombocythemia along with other biological features of these patients. We included 86 patients with polycythemia vera, of which 34 (39.5 %) had major thrombosis and 95 patients with essential thrombocythemia, of which 22 (23.1 %) had major thrombosis. In the whole cohort of patients, only the factor V Leiden mutation was significantly associated with both arterial and venous thrombosis in univariate and multivariate analysis (odds ratio (OR) = 4.3; 95 % confidence interval (CI) = 1.5-12.5; p = 0.008 and OR = 4.3; 95 % CI = 1.2-15.9; p = 0.02, respectively). Other factors significantly associated with thrombosis in both univariate and multivariate analysis were male sex (OR = 2.8, 95 % CI = 1.4-5.4, p = 0.002 and OR = 3.5, 95 % CI = 1.6-7.6, p = 0.002, respectively) and the JAK2 V617F mutation (OR = 5.5, 95 % CI = 2.1-15, p = 0.0001 and OR = 6.9, 95 % CI = 2.2-21.2, p = 0.001, respectively). In conclusion, among the four mutations analyzed (factor V Leiden, prothrombin G20210A, and MTHFR 677 C > T and 1298 A > C), only factor V Leiden is a major contributor to thrombosis in polycythemia vera and essential thrombocythemia. PMID:23828072

  8. A COMMON POLYMORPHISM IN THE METHYLENETETRAHYDROFOLATE REDUCTASE (MTHFR) GENE IS ASSOCIATED WITH QUANTITATIVE ULTRASOUND IN THOSE WITH LOW PLASMA FOLATE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study of a polymorphism in the MTHFR gene, plasma folate, and bone phenotypes in 1632 individuals revealed that the genotype effect on BMD and quantitative ultrasound was dependent on the level of folate. Our findings support the hypothesis that the association between an MTHFR polymorphism and bo...

  9. Opposite effects of plasma homocysteine and the methylenetetrahydrofolate reductase C677T mutation on carotid artery geometry in asymptomatic adults.

    PubMed

    Demuth, K; Moatti, N; Hanon, O; Benoit, M O; Safar, M; Girerd, X

    1998-12-01

    Studies of symptomatic patients have identified hyperhomocysteinemia as an independent risk factor for vascular disease. In case-control studies, a point mutation (C677T) in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) has also been linked to an increased risk of vascular disease through its effect on homocysteinemia. Our aim was to extend these observations to asymptomatic subjects by studying the influence of both homocysteinemia and its mutation on carotid artery geometry. We examined 144 subjects free of atherosclerotic lesions. Fasting homocysteinemia was measured by high-performance liquid chromatography with fluorometric detection. MTHFR genotype was analyzed by polymerase chain reaction followed by HinfI digestion. Carotid artery geometry was characterized by internal diameter and intima-media thickness, as assessed by a high-resolution echo-tracking system. Subjects in the upper homocysteine tertile had a greater carotid internal diameter than did subjects in the middle and lower tertiles (6516+/-770 versus 6206+/-641 and 5985+/-558 microm, respectively; P<0.001). Subjects homozygous for the mutation had a smaller carotid artery internal diameter than did subjects heterozygous or homozygous for the wild-type allele (5846+/-785 versus 6345+/-673 and 6199+/-671 microm, respectively; P<0.05). Homocysteinemia was not significantly increased in subjects homozygous for the mutation. In multivariate regression analysis, homocysteinemia was independently and positively associated with lumen diameter (P=0.0008) and wall thickness (P=0.020). Conversely, homozygosity for the mutation was negatively associated with internal diameter (P=0.009). These preliminary data suggest that mildly elevated homocysteinemia and homozygosity for the MTHFR C677T mutation are associated with opposite preclinical modifications of carotid artery geometry. If confirmed, these results may have important implications for new treatment strategies for vascular disease

  10. Genetic susceptibility of methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms with risk for bladder transitional cell carcinoma in men.

    PubMed

    Safarinejad, Mohammad Reza; Shafiei, Nayyer; Safarinejad, Shiva

    2011-12-01

    We performed a case-control study of 158 bladder transitional cell carcinoma (TCC) cases and 316 controls to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T, A1298G, and G1793A polymorphisms and bladder cancer susceptibility by polymerase chain reaction restriction fragment length polymorphism (PCR-RLFP) technique. The controls were frequency-matched to the cases by age (± 5 years), ethnicity, and smoking status. We also measured serum levels of total homocysteine (tHcy), folate, and vitamin B12. It was found that the 1298AC (odds ratio, OR = 3.74; 95% confidence interval, CI = 2.34-5.47; P = 0.001) and 1298CC (OR = 3.46, 95% CI = 2.37-5.52; P = 0.001) genotypes of MTHFR A1298C were significantly associated with increased risk of bladder TCC. The MTHFR C677T and G1793A polymorphisms were not associated with bladder TCC. After stratification for grade and stage, we observed that the 677TT (OR = 4.47, 95% CI = 2.74-6.72; P = 0.001) and MTHFR 1298CC (OR = 4.78, 95% CI = 2.82-6.89; P = 0.001) genotypes of MTHFR were associated with increased risk of muscle-invasive bladder TCC. We also found that the MTHFR 677CT+1298AA genotypes were associated with an approximately 70% reduction in risk of bladder cancer (OR = 0.31; 95% CI = 0.15-0.68) compared to the combined referent genotype. There were 8 haplotypes and 16 haplotype genotypes based on these three variants. When we used the haplotypes and assumed that the 677T, 1298C, and 1793G alleles were risk alleles, the adjusted odds ratios increased as the number of risk alleles increased: 1.00 for 0-1 variant, 1.88 (1.4-2.7) for any two risk alleles and 2.07 (1.6-2.8) for any three risk alleles. Serum tHcy levels were significantly higher in carriers of the 677T, 1298C, and 1793G alleles compared to noncarriers (all P < 0.01). There was no significant correlation between serum levels of tHcy and folate and bladder cancer risk. Further studies in larger samples size and different

  11. Regulation of Folate-Mediated One-Carbon Metabolism by Glycine N-Methyltransferase (GNMT) and Methylenetetrahydrofolate Reductase (MTHFR).

    PubMed

    Wang, Yi-Cheng; Wu, Ming-Tsung; Lin, Yan-Jun; Tang, Feng-Yao; Ko, Hsin-An; Chiang, En-Pei

    2015-01-01

    Folate-mediated one-carbon metabolism is an important therapeutic target of human diseases. We extensively investigated how gene-nutrient interactions may modulate human cancer risk in 2 major folate metabolic genes, MTHFR and GNMT. The biochemical impacts of MTHFR and GNMT on methyl group supply, global DNA methylation, nucleotide biosynthesis, DNA damage, and partitioning of the folate dependent 1-carbon group were carefully studied. The distinct model systems used included: EB virus-transformed lymphoblasts expressing human MTHFR polymorphic genotypes; liver-derived GNMT-null cell-lines with and without GNMT overexpression; and HepG2 cells with stabilized inhibition of MTHFR using shRNA, GNMT wildtype, heterozygotous (GNMT(het)) and knockout (GNMT(nul)) mice. We discovered that the MTHFR TT genotype significantly reduces folate-dependent remethylation under folate restriction, but it assists purine synthesis when folate is adequate. The advantage of de novo purine synthesis found in the MTHFR TT genotype may account for the protective effect of MTHFR in human hematological malignancies. GNMT affects transmethylation kinetics and S-adenosylmethionine (adoMet) synthesis, and facilitates the conservation of methyl groups by limiting homocysteine remethylation fluxes. Restoring GNMT assists methylfolate-dependent reactions and ameliorates the consequences of folate depletion. GNMT expression in vivo improves folate retention and bioavailability in the liver. Loss of GNMT impairs nucleotide biosynthesis. Over-expression of GNMT enhances nucleotide biosynthesis and improves DNA integrity by reducing uracil misincorporation in DNA both in vitro and in vivo. The systematic series of studies gives new insights into the underlying mechanisms by which MTHFR and GNMT may participate in human tumor prevention. PMID:26598833

  12. Insights on the structural perturbations in human MTHFR Ala222Val mutant by protein modeling and molecular dynamics.

    PubMed

    Abhinand, P A; Shaikh, Faraz; Bhakat, Soumendranath; Radadiya, Ashish; Bhaskar, L V K S; Shah, Anamik; Ragunath, P K

    2016-04-01

    Methylenetetrahydrofolate reductase (MTHFR) protein catalyzes the only biochemical reaction which produces methyltetrahydrofolate, the active form of folic acid essential for several molecular functions. The Ala222Val polymorphism of human MTHFR encodes a thermolabile protein associated with increased risk of neural tube defects and cardiovascular disease. Experimental studies have shown that the mutation does not affect the kinetic properties of MTHFR, but inactivates the protein by increasing flavin adenine dinucleotide (FAD) loss. The lack of completely solved crystal structure of MTHFR is an impediment in understanding the structural perturbations caused by the Ala222Val mutation; computational modeling provides a suitable alternative. The three-dimensional structure of human MTHFR protein was obtained through homology modeling, by taking the MTHFR structures from Escherichia coli and Thermus thermophilus as templates. Subsequently, the modeled structure was docked with FAD using Glide, which revealed a very good binding affinity, authenticated by a Glide XP score of -10.3983 (kcal mol(-1)). The MTHFR was mutated by changing Alanine 222 to Valine. The wild-type MTHFR-FAD complex and the Ala222Val mutant MTHFR-FAD complex were subjected to molecular dynamics simulation over 50 ns period. The average difference in backbone root mean square deviation (RMSD) between wild and mutant variant was found to be ~.11 Å. The greater degree of fluctuations in the mutant protein translates to increased conformational stability as a result of mutation. The FAD-binding ability of the mutant MTHFR was also found to be significantly lowered as a result of decreased protein grip caused by increased conformational flexibility. The study provides insights into the Ala222Val mutation of human MTHFR that induces major conformational changes in the tertiary structure, causing a significant reduction in the FAD-binding affinity. PMID:26273990

  13. Elevated total plasma homocysteine and 667C{r_arrow}T mutation of the 5,10-methylenetetrahydrofolate reductase gene in thrombotic vascular disease

    SciTech Connect

    De Franchis, R.; Sebastio, G.; Andria, G.

    1996-07-01

    Moderate elevation of total plasma homocysteine (tHcy) has been reported as an independent risk factor for thrombotic vascular disease, a well-known multifactorial disorder. Possible genetic causes of elevated tHcy include defects of the sulfur-containing amino acids metabolism due to deficiencies of cystathionine {Beta}-synthase, of 5,10-methylenetetrahydrofolate reductase (MTHFR), and of the enzymes of cobalamin metabolism. An impaired activity of MTHFR due to a thermolabile form of the enzyme has been observed in {le}28% of hyperhomocysteinemic patients with premature vascular disease. More recently, the molecular basis of such enzymatic thermolability has been related to a common mutation of the MTHFR gene, causing a C-to-T substitution at nt 677 (677C{r_arrow}T). This mutation was found in 38% of unselected chromosomes from 57 French Canadian individuals. The homozygous state for the mutation was present in 12% of these subjects and correlated with significantly elevated tHcy. Preliminary evidence indicates that the frequency of homozygotes for the 677C{r_arrow}T mutation may vary significantly in populations from different geographic areas. 5 refs., 2 tabs.

  14. Mthfr as a modifier of the retinal phenotype of Crb1(rd8/rd8) mice.

    PubMed

    Markand, Shanu; Saul, Alan; Tawfik, Amany; Cui, Xuezhi; Rozen, Rima; Smith, Sylvia B

    2016-04-01

    Mutations in crumb homologue 1 (CRB1) in humans are associated with Leber's congenital amaurosis (LCA) and retinitis pigmentosa (RP). There is no clear genotype-phenotype correlation for human CRB1 mutations in RP and LCA. The high variability in clinical features observed in CRB1 mutations suggests that environmental factors or genetic modifiers influence severity of CRB1 related retinopathies. Retinal degeneration 8 (rd8) is a spontaneous mutation in the Crb1 gene (Crb1(rdr/rd8)). Crb1(rdr/rd8) mice present with focal disruption in the outer retina manifesting as white spots on fundus examination. Mild retinal dysfunction with decreased b-wave amplitude has been reported in Crb1(rdr/rd8) mice at 18 months. Methylene tetrahydrofolate reductase (MTHFR) is a crucial enzyme of homocysteine metabolism. MTHFR mutations are prevalent in humans and are linked to a broad spectrum of disorders including cardiovascular and neurodegenerative diseases. We recently reported the retinal phenotype in Mthfr-deficient (Mthfr(+/-)) heterozygous mice. At 24 weeks the mice showed decreased RGC function, thinner nerve fiber layer, focal areas of vascular leakage and 20% fewer cells in the ganglion cell layer (GCL). Considering the variability in CRB1-related retinopathies and the high occurrence of human MTHFR mutations we evaluated whether Mthfr deficiency influences rd8 retinal phenotype. Mthfr heterozygous mice with rd8 mutations (Mthfr(+/-)(rd8/rd8)) and Crb(rd8/rd8) mice (Mthfr(+/+rd8/rd8)) mice were subjected to comprehensive retinal evaluation using ERG, fundoscopy, fluorescein angiography (FA), morphometric and retinal flat mount immunostaining analyses of isolectin-B4 at 8-54 wks. Assessment of retinal function revealed a significant decrease in the a-, b- and c-wave amplitudes in Mthfr(+/-)(rd8/rd8) mice at 52 wks. Fundoscopic evaluation demonstrated the presence of signature rd8 spots in Mthfr(+/+rd8/rd8) mice and an increase in the extent of these rd8 spots in Mthfr

  15. Severe methylenetetrahydrofolate reductase deficiency revealed by a pulmonary embolism in a young adult.

    PubMed

    Tonetti, Carole; Ruivard, Marc; Rieu, Virginie; Zittoun, Jacqueline; Giraudier, Stephane

    2002-11-01

    Deficiency in methylenetetrahydrofolate reductase (MTHFR), the enzyme involved in the remethylation of homocysteine to methionine using methyltetrahydrofolate as cofactor, induces hyperhomocysteinaemia, homocysteinuria, hypomethioninaemia and low methylfolate levels. Diagnosis usually occurs during infancy because of various neurological abnormalities. We report MTHFR deficiency diagnosed in an adult woman after a pulmonary embolism. Her adult sister, intellectually retarded, suffered from the same disease. Molecular analysis of the MTHFR gene exhibited four different mutations (two missense mutations, one exon skipping and C677T). The impact of these mutations was analysed through the biological abnormalities in the parents and children. PMID:12406076

  16. MTHFR (C677T) polymorphism and PR (PROGINS) mutation as genetic factors for preterm delivery, fetal death and low birth weight: A Northeast Indian population based study

    PubMed Central

    Tiwari, Diptika; Bose, Purabi Deka; Das, Somdatta; Das, Chandana Ray; Datta, Ratul; Bose, Sujoy

    2015-01-01

    Preterm delivery (PTD) is one of the most significant contributors to neonatal mortality, morbidity, and long-term adverse consequences for health; with highest prevalence reported from India. The incidence of PTD is alarmingly very high in Northeast India. The objective of the present study is to evaluate the associative role of MTHFR gene polymorphism and progesterone receptor (PR) gene mutation (PROGINS) in susceptibility to PTD, negative pregnancy outcome and low birth weights (LBW) in Northeast Indian population. Methods A total of 209 PTD cases {extreme preterm (< 28 weeks of gestation, n = 22), very preterm (28–32 weeks of gestation, n = 43) and moderate preterm (32–37 weeks of gestation, n = 144) and 194 term delivery cases were studied for MTHFR C677T polymorphism and PR (PROGINS) gene mutation. Statistical analysis was performed using SPSS software. Results Distribution of MTHFR and PR mutation was higher in PTD cases. Presence of MTHFR C677T polymorphism was significantly associated and resulted in the increased risk of PTD (p < 0.001), negative pregnancy outcome (p < 0.001) and LBW (p = 0.001); more significantly in extreme and very preterm cases. Presence of PR mutation (PROGINS) also resulted in increased risk of PTD and negative pregnancy outcome; but importantly was found to increase the risk of LBW significantly in case of very preterm (p < 0.001) and moderately preterm (p < 0.001) delivery cases. Conclusions Both MTHFR C677T polymorphism and PR (PROGINS) mutation are evident genetic risk factors associated with the susceptibility of PTD, negative pregnancy outcome and LBW. MTHFR C677T may be used as a prognostic marker to stratify subpopulation of pregnancy cases predisposed to PTD; thereby controlling the risks associated with PTD. PMID:25709895

  17. Hyperbaric Oxygen Therapy in Branch Retinal Artery Occlusion in a 15-Year-Old Boy with Methylenetetrahydrofolate Reductase Mutation

    PubMed Central

    Kadayifcilar, Sibel; Eldem, Bora

    2015-01-01

    Purpose. To report the efficacy of hyperbaric oxygen (HBO) therapy in a case of branch retinal artery occlusion (BRAO) in a 15-year-old boy. Methods. We report a 15-year-old boy with sudden loss of vision due to BRAO. Examination included laboratory evaluation for systemic risk factors. Follow-up exams included visual acuity, fundus examination, fundus fluorescein angiography, and visual field testing. HBO therapy was employed for treatment. Results. Medical history was positive for isolated glucocorticoid deficiency. Laboratory evaluation disclosed hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) mutation. The visual acuity 0.05 at presentation improved to 0.8 after 20 days of HBO therapy. There was no change on visual fields. Conclusion. In this pediatric case, HBO therapy was useful in the treatment of BRAO. PMID:25722905

  18. Increased MTHFR promoter methylation in mothers of Down syndrome individuals.

    PubMed

    Coppedè, Fabio; Denaro, Maria; Tannorella, Pierpaola; Migliore, Lucia

    2016-05-01

    Despite that advanced maternal age at conception represents the major risk factor for the birth of a child with Down syndrome (DS), most of DS babies are born from women aging less than 35 years. Studies performed in peripheral lymphocytes of those women revealed several markers of global genome instability, including an increased frequency of micronuclei, shorter telomeres and impaired global DNA methylation. Furthermore, young mothers of DS individuals (MDS) are at increased risk to develop dementia later in life, suggesting that they might be "biologically older" than mothers of euploid babies of similar age. Mutations in folate pathway genes, and particularly in the methylenetetrahydrofolate reductase (MTHFR) one, have been often associated with maternal risk for a DS birth as well as with risk of dementia in the elderly. Recent studies pointed out that also changes in MTHFR methylation levels can contribute to human disease, but nothing is known about MTHFR methylation in MDS tissues. We investigated MTHFR promoter methylation in DNA extracted from perypheral lymphocytes of 40 MDS and 44 matched control women that coinceived their children before 35 years of age, observing a significantly increased MTHFR promoter methylation in the first group (33.3 ± 8.1% vs. 28.3 ± 5.8%; p=0.001). In addition, the frequency of micronucleated lymphocytes was available from the women included in the study, was higher in MDS than control mothers (16.1 ± 8.6‰ vs. 10.5 ± 4.3‰; p=0.0004), and correlated with MTHFR promoter methylation levels (r=0.33; p=0.006). Present data suggest that MTHFR epimutations are likely to contribute to the increased genomic instability observed in cells from MDS, and could play a role in the risk of birth of a child with DS as well as in the onset of age related diseases in those women. PMID:26926955

  19. Effectiveness of add-on l-methylfolate therapy in a complex psychiatric illness with MTHFR C677 T genetic polymorphism.

    PubMed

    Jha, Shailesh; Kumar, Pankaj; Kumar, Rajesh; Das, Aparna

    2016-08-01

    The 5,10-methylenetetrahydrofolate reductase (MTHFR) gene plays a central role in folate metabolism. Many studies have demonstrated an association between MTHFR C677 T variant with depression, schizophrenia and bipolar disorder as one of them being comorbid to other. This has justified the use of folate supplement in psychiatric disorders mainly depression but still not in various other comorbid complex psychiatric disorders. Here we have tried to show how the l-methylfolate in conjunction with the conventional psychotropic drugs can be useful in a state of such complex psychiatric phenomenon and comorbid diagnosis with genetic polymorphism of MTHFR C677 T mutation. PMID:27520898

  20. Molecular analysis of factor V Leiden, factor V Hong Kong, factor II G20210A, methylenetetrahydrofolate reductase C677T, and A1298C mutations related to Turkish thrombosis patients.

    PubMed

    Dölek, Bilgen; Eraslan, Serpil; Eroğlu, Sevim; Kesim, Belgin Eroglu; Ulutin, Turgut; Yalçiner, Altan; Laleli, Yahya R; Gözükirmizi, Nermin

    2007-10-01

    Inherited gene disorders related to the hemostatic system have been documented as risk factors for thrombosis. The roles of factor V Hong Kong (FV Hong Kong), factor V Leiden (FV Leiden), factor II G20210A (FII G20210A), methylenetetrahydrofolate reductase (MTHFR) C677T, and MTHFR A1298C mutations in Turkish patients with thrombosis (270 patients) compared with healthy controls (114 subjects) were evaluated. Polymerase chain reaction-based restriction enzyme analysis was carried out to screen these mutations, and single-strand conformation analysis was established to identify variations using the primers selected for restriction enzyme analysis studies. As a result, a significant relationship was determined among FV Leiden, FII G20210A, and thrombosis. The FV Hong Kong mutation was observed in only 2 patients with pulmonary vein thrombosis who are FV Leiden/FV Hong Kong compound heterozygous for FV gene. MTHFR C677T and A1298C were equally distributed in the patient group compared with the control group. All named mutations were also identified with single-strand conformation analysis, but a new variant/polymorphism during studies was not found. Because some inherited abnormalities are associated with thromboembolic disorders, determining the mutations and gene-to-gene interactions in patients with thrombosis history has a great impact on diagnosis and treatment of these diseases. PMID:17911197

  1. [Relationship of MTHFR gene polymorphisms with infertility].

    PubMed

    Guo, Kai-min; Tian, Run-hui; Wang, Hong-liang

    2016-02-01

    The folate metabolic pathway plays important roles in cellular physiology by participating in nucleotide synthesis, DNA repair and methylation, and maintenance and stability of the genome. Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme involved in folate metabolism. Polymorphisms of MTHFR may change the level of homocysteine and affect DNA synthesis and methylation, leading to an increased oxidative stress and disturbed methylation reactions and consequently affecting reproductive function. This article presents an overview on MTHFR gene polymorphisms, proposing that multicentered, large-sample and long-term prospective studies are needed to reveal the relationship between MTHFR gene polymorphisms and infertility. PMID:26939404

  2. MTHFR C677T and prothrombin G20210A mutations in a woman from Dalmatia with silent brain infarction. .

    PubMed

    Ivica, Nikolina; Pintarić, Irena; Titlić, Marina

    2014-09-01

    A 55-year-old, previously healthy woman, presented with frequent headaches. She had no neurological disturbances, but had a positive family history; her father died from stroke. Magnetic resonance imaging showed brain infarction; therefore detailed diagnostic evaluation of thrombophilia markers and genetic testing were performed. The patient was found to be homozy- gous for the C677T mutation of the methylenetetrahydrofolate reductase gene and heterozygous for the mutation of the prothrombin G20210A gene. No other cause of cerebral infarction was found in the patient. PMID:25509247

  3. Livedoid vasculopathy in a patient with lupus anticoagulant and MTHFR mutation: treatment with low-molecular-weight heparin.

    PubMed

    Abou Rahal, Jihane; Ishak, Rim S; Otrock, Zaher K; Kibbi, Abdul-Ghani; Taher, Ali T

    2012-11-01

    Livedoid vasculopathy is characterized by painful purpuric lesions on the extremities which frequently ulcerate and heal with atrophic scarring. For many years, livedoid vasculopathy has been considered to be a primary vasculitic process. However, there has been evidence considering livedoid vasculopathy as an occlusive vasculopathy due to a hypercoagulable state. We present the case of livedoid vasculopathy in a 21-year-old female who had been suffering of painful lower extremity lesions of 3 years duration. The patient was found to be lupus anticoagulant positive and homozygous for methylenetetrahydrofolate reductase C677T mutation. The patient was successfully treated with low-molecular-weight heparin. PMID:22592843

  4. Antifolates and MTHFR.

    PubMed

    Trachtman, Joseph N; Pagano, Vincent

    2015-12-01

    We describe a patient who developed symptoms of headache, fatigue, and dizziness after administration of terbinafine (Lamisil). Laboratory tests revealed that he is heterozygous for the C677T variation of the methylenetetrahydrofolate reductase genetic mutation. The prescription of Deplin (L-methylfolate) greatly reduced the symptoms. It was later noted that Lamisil's mechanism of action interferes with cells' methylation cycle, which we suspect compromises cellular function in people with the methylenetetrahydrofolate reductase genetic mutation. PMID:25929315

  5. Massive pulmonary embolism associated with Factor V Leiden, prothrombin, and methylenetetrahydrofolate reductase gene mutations in a young patient on oral contraceptive pills: a case report.

    PubMed

    Charafeddine, Khalil M; Mahfouz, Rami A; Ibrahim, Georges Y; Taher, Ali T; Hoballah, Jamal J; Taha, Assad M

    2010-10-01

    Factor V Leiden (Factor V G1691A), prothrombin gene mutation G20210A, and homozygous C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene are known to predispose venous thromboembolism (VTE). We present herein a rare case of a young woman heterozygous for these mutations and taking oral contraceptive pills for less than 2 months, diagnosed to have massive deep venous thrombosis and bilateral pulmonary embolism. The patient was managed for 10 days in the hospital and discharged home on oral anticoagulants. This case suggests that screening for these factors in people with family history of thrombosis and in relatives of patients with these mutations is highly recommended to prevent fatal consequences. In addition, a new guideline for treatment and prophylaxis with anticoagulant for these patients and others who are at risk of developing VTE (American College of Chest Physicians [ACCP] guidelines-Chest 2008) has been published recently. Our recommendation is to promote for the internationally published algorithms through their application, where necessary, to prevent any future thrombotic morbidity or mortality incidents. PMID:19520679

  6. Methylenetetrahydrofolate Reductase Gene Polymorphisms in Children with Attention Deficit Hyperactivity Disorder

    PubMed Central

    Gokcen, Cem; Kocak, Nadir; Pekgor, Ahmet

    2011-01-01

    Objective: The purpose of this study was to evaluate the relationship between 5,10- methylenetetrahydrofolate reductase (MTHFR) polymorphisms and Attention Deficit Hyperactivity Disorder (ADHD) in a sample of Turkish children. Study Design: MTHFR gene polymorphisms were assessed in 40 patients with ADHD and 30 healty controls. Two mutations in the MTHFR gene were investigated using polymerase chain reactions and restriction fragment length polymorphisms. Results: Although there were no statistically significant differences in genotype distributions of the C677T alleles between the ADHD and the control groups (p=0,678) but the genotypic pattern of the distributions of the A1298C alleles was different between the ADHD patients and the controls (p=0,033). Conclusions: Preliminary data imply a possible relationship between A1298C MTHFR polymorphisms and the ADHD. PMID:21897766

  7. Homocysteine Metabolism Gene Polymorphisms (MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) Jointly Elevate the Risk of Folate Deficiency.

    PubMed

    Li, Wen-Xing; Dai, Shao-Xing; Zheng, Jun-Juan; Liu, Jia-Qian; Huang, Jing-Fei

    2015-08-01

    Folate deficiency is strongly associated with cardiovascular disease. We aimed to explore the joint effect of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, and methionine synthase reductase (MTRR) A66G polymorphisms on folate deficiency in a Chinese hypertensive population. A total of 480 subjects aged 28-75 were enrolled in this study from September 2005-December 2005 from six hospitals in different Chinese regions. Known genotypes were detected by PCR-RFLP methods and serum folate was measured by chemiluminescence immunoassay. Our results showed that MTHFR 677TT and MTR 2756AG + GG were independently associated with a higher risk of folate deficiency (TT vs. CC + CT, p < 0.001 and AG + GG vs. AA p = 0.030, respectively). However, the MTHFR A1298C mutation may confer protection by elevating the serum folate level (p = 0.025). Furthermore, patients carrying two or more risk genotypes showed higher odds of folate deficiency than null risk genotype carriers, especially those carrying four risk genotypes. These findings were verified by generalized multifactor dimensionality reduction (p = 0.0107) and a cumulative effects model (p = 0.001). The results of this study have shown that interactions among homocysteine metabolism gene polymorphisms lead to dramatic elevations in the folate deficiency risk. PMID:26266420

  8. Homocysteine Metabolism Gene Polymorphisms (MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) Jointly Elevate the Risk of Folate Deficiency

    PubMed Central

    Li, Wen-Xing; Dai, Shao-Xing; Zheng, Jun-Juan; Liu, Jia-Qian; Huang, Jing-Fei

    2015-01-01

    Folate deficiency is strongly associated with cardiovascular disease. We aimed to explore the joint effect of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, and methionine synthase reductase (MTRR) A66G polymorphisms on folate deficiency in a Chinese hypertensive population. A total of 480 subjects aged 28–75 were enrolled in this study from September 2005–December 2005 from six hospitals in different Chinese regions. Known genotypes were detected by PCR-RFLP methods and serum folate was measured by chemiluminescence immunoassay. Our results showed that MTHFR 677TT and MTR 2756AG + GG were independently associated with a higher risk of folate deficiency (TT vs. CC + CT, p < 0.001 and AG + GG vs. AA p = 0.030, respectively). However, the MTHFR A1298C mutation may confer protection by elevating the serum folate level (p = 0.025). Furthermore, patients carrying two or more risk genotypes showed higher odds of folate deficiency than null risk genotype carriers, especially those carrying four risk genotypes. These findings were verified by generalized multifactor dimensionality reduction (p = 0.0107) and a cumulative effects model (p = 0.001). The results of this study have shown that interactions among homocysteine metabolism gene polymorphisms lead to dramatic elevations in the folate deficiency risk. PMID:26266420

  9. Evaluation of High Resolution Melting for MTHFR C677T Genotyping in Congenital Heart Disease

    PubMed Central

    Yue, Shuying; Zhang, Kun; Wang, Hui; Dong, Rui; Yang, Xiaomeng; Liu, Yi; Ma, Yanhui

    2016-01-01

    Background High resolution melting (HRM) is a simple, flexible and low-cost mutation screening technique. The methylenetetrahydrofolate reductase (MTHFR) gene encoding a critical enzyme, potentially affects susceptibility to some congenital defects like congenital heart disease (CHD). We evaluate the performance of HRM for genotyping of the MTHFR gene C677T locus in CHD cases and healthy controls of Chinese Han population. Methods A total of 315 blood samples from 147 CHD patients (male72, female 75) and 168 healthy controls (male 92, female 76) were enrolled in the study. HRM was utilized to genotype MTHFR C677T locus of all the samples. The results were compared to that of PCR-RFLP and Sanger sequencing. The association of the MTHFR C677T genotypes and the risk of CHD was analyzed using odds ratio with their 95% confidence interval (CIs) from unconditional logistic regression. Results All the samples were successfully genotyped by HRM within 1 hour and 30 minutes while at least 6 hours were needed for PCR-RFLP and sequencing. The genotypes of MTHFR C677T CC, CT, and TT were 9.52%, 49.66%, and 40.82% in CHD group but 29.17%, 50% and 20.83% in control group, which were identical using both methods of HRM and PCR-RFLP, demonstrating the sensitivity and specificity of HRM were all 100%. Conclusion MTHFR C677T is a potential risk factor for CHD in our local residents of Shandong province in China. HRM is a fast, sensitive, specific and reliable method for clinical application of genotyping. PMID:26990189

  10. [Methylenetetrahydrofolate reductase deficiency-induced schizophrenia in a school-age boy].

    PubMed

    Wang, Qiao; Liu, Jing; Liu, Yu-Peng; Li, Xi-Yuan; Ma, Yan-Yan; Wu, Tong-Fei; Ding, Yuan; Song, Jin-Qing; Wang, Yu-Jie; Yang, Yan-Ling

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessive disorder. It is known that MTHFR deficiency may result in hyperhomocysteinemia, but MTHFR deficiency-induced schizophrenia has been rarely reported. Here we present the clinical course, biochemical and genetic characteristics of schizophrenia resulted from MTHFR deficiency in a school-age boy. He was 13 years old. He was admitted with a two-year history of fear, auditory hallucination, learning difficulty, sleeping problems, irascibility, drowsing and giggling. At admission, he had significantly elevated plasma and urine levels of total homocysteine, significantly decreased levels of folate in serum and cerebrospinal fluid, and a normal blood concentration of methionine. Further DNA sequencing analysis showed 665C>T homozygous mutations in the MTHFR gene. The patient was diagnosed with MTHFR deficiency-associated schizophrenia and treatment with calcium folinate, vitamin B12, vitamin B6, and betaine was initiated. After the treatment for 1 week, his plasma and urine levels of homocysteine were decreased to a normal range and the clinical symptoms were significantly improved. After 3 months of treatment, the patient returned to school. He is now living with normal school life. In summary, children with late-onset MTHFR deficiency and secondary cerebral folate deficiency may lead to schizophrenia. This rare condition can be early diagnosed through analyses of blood and urine total homocysteine, amino acids in blood and folate in blood and cerebral fluid and successfully treated with folinic acid, vitamin B6, vitamin B12 and betaine. PMID:24461181

  11. Severe scoliosis in a patient with severe methylenetetrahydrofolate reductase deficiency.

    PubMed

    Munoz, Tatiana; Patel, Jinesh; Badilla-Porras, Ramses; Kronick, Jonathan; Mercimek-Mahmutoglu, Saadet

    2015-01-01

    Severe methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessively inherited inborn error of folate metabolism. We report a new patient with severe MTHFR deficiency who presented at age 4 months with early onset severe scoliosis associated with severe hypotonia. Markedly decreased MTHFR enzyme activity (0.3 nmoles CHO/mg protein/h; reference range>9) and compound heterozygous mutations (c. 1304T>C; p.Phe435Ser and c.1539dup; p.Glu514Argfs∗24) in the MTHFR gene confirmed the diagnosis. She was treated with vitamin B12, folic acid and betaine supplementation and showed improvements in her developmental milestones and hypotonia. To the best of our knowledge, this is the first patient with MTHFR deficiency reported with severe early onset scoliosis. Despite the late diagnosis and treatment initiation, she showed favorable short-term neurodevelopmental outcome. This case suggests that homocysteine measurement should be included in the investigations of patients with developmental delay, hypotonia and scoliosis within first year of life prior to organizing genetic investigations. PMID:24726568

  12. Maternal Supplementary Folate Intake, Methylenetetrahydrofolate Reductase (MTHFR) C677T and A1298C Polymorphisms and the Risk of Orofacial Cleft in Iranian Children

    PubMed Central

    Ebadifar, Asghar; KhorramKhorshid, Hamid Reza; Kamali, Koorosh; Salehi Zeinabadi, Mehdi; Khoshbakht, Tayyebeh; Ameli, Nazila

    2015-01-01

    Background: The purpose of this study was to describe the association of MTHFR gene single nucleotide polymorphisms (C677T and A1298C) and maternal supplementary folate intake with orofacial clefts in the Iranian population. Methods: In this case-control study, peripheral venous blood was taken from 65 patients with orofacial clefts and 215 unaffected controls for DNA extraction and kept in EDTA for further analysis. The genotyping was carried out using Polymerase Chain Reaction (PCR) followed by Restriction Fragment Length Polymorphism (RFLP) and gel electrophoresis. Data were analyzed using Chi square test and logistic regression tests. Results: Genotype frequencies of 677TT were reported to be 13.5 and 36.1% in controls and CL/P patients, respectively, which showed a significant difference compared to CC as reference (OR=4.118; 95% CI=1.997–8.492; p=0.001). Conversely, 1298CC with frequencies of 10.8 and 12.7% in controls and patients, respectively, showed no significant difference compared to AA (OR=2.359; 95% CI=0.792–7.023; p=0.123). Comparing patients whose mothers did not report the folate supplement intake during pregnancy, to controls, it was observed that lack of folate intake was a predisposing factor for having a child with oral clefts (OR=5/718, p=0.000). Conclusion: Children carrying the 677TT variant of the MTHFR gene may have an increased risk of CL/P. In addition, the finding that the risk associated with this allele was obviously higher when the mothers didn’t use folic acid, supports the hypothesis that folic acid may play a role in the etiology of CL/P. PMID:26140186

  13. Study on Environmental Causes and SNPs of MTHFR, MS and CBS Genes Related to Congenital Heart Disease

    PubMed Central

    Liu, Yan; Huang, Peng; Lin, Ning; Sun, Xiaoru; Yu, Rongbin; Zhang, Yuanyuan; Qin, Yuming; Wang, Lijuan

    2015-01-01

    Purpose Congenital heart diseases (CHD) are among the most common birth defects in China. Environmental causes and folate metabolism changes may alter susceptibility to CHD. The aim of this study is to evaluate the relevant risk-factors of children with CHD and their mothers. Methods 138 children with CHD and 207 normal children for controls were recruited. Their mothers were also enlisted in this study and interviewed following a questionnaire about their pregnant history and early pregnancy situation. Five single nucleotide polymorphisms (SNPs) in methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MS) and cystathionine β-synthase (CBS) of mothers and children were genotyped. Results There were significant differences in the gender of children, occupation of mothers, family history with CHD, history of abortion, history of adverse pregnancy, early pregnancy health, fetus during pregnancy, pesticide exposure and drug exposure in CHD group and control group ( P < 0.05). Logistic regression analyses showed that after adjustment for above factors, MTHFR rs1801131 were significantly associated with their offspring CHD risk in mothers. Compared with the mothers whose MTHFR were rs1801131 AA and AC genotypes, the mothers who got a mutation of MTHFR rs1801131 CC genotypes had a 267% increase in risk of given birth of a CHD children (OR=3.67,95%CI=1.12-12.05). Meanwhile, MTHFR rs1801131 were significantly associated with CHD susceptibility in children (OR = 1.42, 95% CI = 1.00-2.44 in additive model). Conclusions Besides mothers’ social and fertility characteristics, our results suggested that the genetic variants in folate metabolism pathway might be one of the most related risk-factors of CHD. MTHFR rs1801131 were identified as loci in Chinese population that were involved in CHD. PMID:26035828

  14. Point mutations in dihydrofolate reductase and dihydropteroate synthase genes of Plasmodium falciparum isolates from Venezuela.

    PubMed

    Urdaneta, L; Plowe, C; Goldman, I; Lal, A A

    1999-09-01

    The present study was designed to characterize mutations in dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes of Plasmodium falciparum in the Bolivar region of Venezuela, where high levels of clinical resistance to sulfadoxine-pyrimethamine (SP, Fansidar; F. Hoffman-La Roche, Basel, Switzerland) has been documented. We used a nested mutation-specific polymerase chain reaction and restriction digestion methods to measure 1) the prevalence of DHFR mutations at 16, 50, 51, 59, 108, and 164 codon positions, and 2) the prevalence of mutations in the 436, 437, 581, and 613 codon sites in DHPS gene. In the case of the DHFR gene, of the 54 parasite isolates analyzed, we detected the presence of Asn-108 and Ile-51 in 96% of the isolates and Arg-50 mutation in 64% of the isolates. Each of these mutations has been associated with high level of resistance to pyrimethamine. Only 2 samples (4%) showed the wild type Ser-108 mutation and none showed Thr-108 and Val-16 mutations that are specific for resistance to cycloguanil. In the case of DHPS gene, we found a mutation at position 437 (Gly) in 100% of the isolates and Gly-581 in 96% of the isolates. The simultaneous presence of mutations Asn-108 and Ile-51 in the DHFR gene and Gly-437 and Gly-581 in the DHPS gene in 96% of the samples tested suggested that a cumulative effect of mutations could be the major mechanism conferring high SP resistance in this area. PMID:10497990

  15. MTHFR gene C677T polymorphism and type 2 diabetic nephropathy in Asian populations: a meta-analysis

    PubMed Central

    Chen, Haiyan; Wei, Fang; Wang, Lihua; Wang, Zhe; Meng, Jia; Jia, Lan; Sun, Guijiang; Zhang, Ruining; Li, Bo; Yu, Haibo; Pang, Haiyan; Bi, Xueqing; Dong, Hongye; Jiang, Aili; Wang, Lin

    2015-01-01

    Background: Many studies have suggested a correlation between the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene and diabetic nephropathy (DN), but their results are inconclusive. Methods: To confirm this correlation, we performed a meta-analysis of 15 studies. The dichotomous data are presented as odds ratios (OR) with 95% confidence intervals (CI). Results: The results of this study suggested that the MTHFR 677 T allele was more likely to increase the risk of DN in Asian (OR = 1.466, 95% CI = 1.143-1.880, P = 0.003), West Asian (OR = 1.750, 95% CI = 1.150-2.664, P = 0.009), and Chinese populations (OR = 2.162, 95% CI = 1.719-2.719, P = 0.001), but not in East Asian or Japanese populations. The carriers of the MTHFR 677 T allele were associated with progression of DN in the “5-10 year duration” group, but not in the “> 10 year duration” group (OR = 2.187, 95% CI = 1.787-2.677, P = 0.001). Conclusion: Development of DN is associated with MTHFR C677T polymorphisms in Asian populations, especially in early type 2 diabetes. PMID:26064261

  16. MTHFR 677 CT/MTHFR 1298 CC genotypes are associated with increased risk of hypertension in Indians.

    PubMed

    Markan, Suchita; Sachdeva, Meenakshi; Sehrawat, Badan Singh; Kumari, Savita; Jain, Sanjay; Khullar, Madhu

    2007-08-01

    The goals of our present study were to measure plasma homocysteine levels and determine their association with methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (C677T and A1298C) in essential hypertensive subjects. Plasma total homocysteine and folic acid levels were measured in essential hypertensive patients (n = 153) before and after oral supplementation with either 5 mg folic acid tablet/day or 5 mg placebo/day for 4 weeks and compared with age and sex matched normotensive controls (n = 133). MTHFR gene polymorphisms (C677T and A1298C) were studied by restriction fragment length polymorphism and correlated with plasma homocysteine levels. Homocysteine levels were significantly higher in hypertensive patients as compared to controls and showed a negative correlation with plasma folate levels. Folic acid supplementation (5 mg/day) for 4 weeks resulted in a significant decrease in plasma homocysteine concentrations in these patients. Patients carrying MTHFR 677T allele (OR = 1.90; 95%CI: 1.14-3.19) or MTHFR 1298C (OR = 2.6, 95%CI: 1.55-4.40) allele were at increased risk of hypertension. The frequency of co-occurrence of MTHFR 677 CT/1298 CC genotypes was significantly higher in the patients compared to controls (P < 0.05) and was associated with increased risk of hypertension (OR = 3.54, 95%CI: 0.37-4.30). Subjects with MTHFR 1298 CC genotype had significantly higher homocysteine levels compared to those with MTHFR 1298 AA genotype (P < 0.05). Our results indicate that MTHFR 677T and 1298C alleles and co-occurrence of MTHFR 677 CT/MTHFR 1298 CC genotypes are associated with increased risk of hypertension and MTHFR 1298 CC genotype is associated with higher homocysteine levels in our subjects. PMID:17333388

  17. Renal transplantation experience in a patient with factor V Leiden homozygous, MTHFR C677T heterozygous, and PAI heterozygous mutation.

    PubMed

    Gülhan, Bora; Tavil, Betül; Gümrük, Fatma; Aki, Tuncay F; Topaloglu, Rezan

    2015-08-01

    Vascular complications are important causes of allograft loss in renal transplantation. A two and a half-month-old boy was diagnosed with posterior urethral valve and progressed to end-stage renal disease at eight yr of age. During the HD period, a central venous catheter was replaced three times for repeated thrombosis. The boy was found to be homozygous for FVL and heterozygous for both MTHFR (C677T) and PAI. At the age of 12, renal transplantation was performed from a deceased donor. Postoperative anticoagulation therapy was initiated with continuous intravenous administration of heparin at the dose of 10 IU/kg/h. HD was performed for the first three days. By the fourth day of transplantation, his urine output had increased gradually. Heparin infusion was continued for 18 days during hospitalization at the same dosage. Thereafter, he was discharged with LMWH. On the third month after transplantation, his serum creatinine level was 1.1 mg/dL and eGFR was 75.7 mL/min/1.73 m(2). He has still been using LMWH, and his eGFR was 78.7 mL/min/1.73 m(2) eight months after transplantation. Postoperative low-dose heparin treatment is a safe strategy for managing a patient with multiple thrombotic risk factors. PMID:25996881

  18. Mthfr gene ablation enhances susceptibility to arsenic prenatal toxicity

    SciTech Connect

    Wlodarczyk, Bogdan J. Zhu, Huiping; Finnell, Richard H.

    2014-02-15

    Background: In utero exposure to arsenic is known to adversely affect reproductive outcomes. Evidence of arsenic teratogenicity varies widely and depends on individual genotypic differences in sensitivity to As. In this study, we investigated the potential interaction between 5,10-methylenetetrahydrofolate reductase (Mthfr) genotype and arsenic embryotoxicity using the Mthfr knockout mouse model. Methods: Pregnant dams were treated with sodium arsenate, and reproductive outcomes including: implantation, resorption, congenital malformation and fetal birth weight were recorded at E18.5. Results: When the dams in Mthfr{sup +/−} × Mthfr{sup +/−} matings were treated with 7.2 mg/kg As, the resorption rate increased to 43.4%, from a background frequency of 7.2%. The As treatment also induced external malformations (40.9%) and significantly lowered the average fetal birth weight among fetuses, without any obvious toxic effect on the dam. When comparing the pregnancy outcomes resulting from different mating scenarios (Mthfr{sup +/+} × Mthfr{sup +/−}, Mthfr{sup +/−} × Mthfr{sup +/−} and Mthfr{sup −/−} × {sup Mthfr+/−}) and arsenic exposure; the resorption rate showed a linear relationship with the number of null alleles (0, 1 or 2) in the Mthfr dams. Fetuses from nullizygous dams had the highest rate of external malformations (43%) and lowest average birth weight. When comparing the outcomes of reciprocal matings (nullizygote × wild-type versus wild-type × nullizygote) after As treatment, the null dams showed significantly higher rates of resorptions and malformations, along with lower fetal birth weights. Conclusions: Maternal genotype contributes to the sensitivity of As embryotoxicity in the Mthfr mouse model. The fetal genotype, however, does not appear to affect the reproductive outcome after in utero As exposure. - Highlights: • An interaction between Mthfr genotype and arsenic embryotoxicity is presented. • Maternal Mthfr genotype

  19. [Clinical comments on genetic marker prevalence (factor V Leiden, prothrombin 20210A and homozygous methylenetetrahydrofolate reductase form [Ho-MTHFR]): based on a study conducted in Health Department No. 19 of the Valencian Community].

    PubMed

    García-Hernández, M C; Romero Casanova, A; Marco Vera, P

    2007-01-01

    The prevalence of genetic markers in ETV disease patients in the 19th Health Department of Valencian Community were: FVL: 9.2%; PT20210 A: 10.5% and Ho-MTHFR: 23.7%. The FVL and PT20210 A prevalence results are lower respect to the literature, while Ho-MTHFR patients, have a higher prevalence with statistical significance difference respect the control group. We considered FVL, PT20210 A and Ho-MTHFR as ETV risk markers. The prevalence of genetic markers in healthy population of the same Health Department were: FVL: 5.8%; PT20210 A: 7.1%, and Ho-MTHFR: 7.7%. We must considered the specific study of these genetic risk markers (FVL, PT20210 A, Ho-MTHFR) in ETV disease affected subjects. The study of first degree relatives of the analyzed patients, should be of great utility to planified genetic advice and practice ETV prophylaxis. PMID:17306151

  20. Conversion of 5-formyltetrahydrofolic acid to 5-methyltetrahydrofolic acid is unimpaired in folate-adequate persons homozygous for the C677T mutation in the methylenetetrahydrofolate reductase gene.

    PubMed

    Stern, L L; Bagley, P J; Rosenberg, I H; Selhub, J

    2000-09-01

    Methylenetetrahydrofolate reductase (MTHFR) catalyzes the synthesis of 5-methyltetrahydrofolic acid (5-CH(3)-H(4) folic acid), the methyl donor for the formation of methionine from homocysteine. A common C677T transition in the MTHFR gene results in a variant with a lower specific activity and a greater sensitivity to heat than the normal enzyme, as measured in vitro. This study was undertaken to determine the capacity of homozygotes for the MTHFR C677T transition to convert 5-formyltetrahydrofolic acid (5-HCO-H(4) folic acid) to 5-CH(3)-H(4) folic acid, a process that requires the action of MTHFR. Six subjects homozygous for the C677T transition (T/T) and 6 subjects with wild-type MTHFR (C/C) were given a 5-mg oral dose of (6R:,S:)-5-HCO-H(4) folic acid. Plasma and urine were analyzed for 5-CH(3)-H(4) folic acid concentrations using affinity/HPLC coupled with fluorescence or UV detection. The mean areas under the curves created by the rise and fall of plasma 5-CH(3)-H(4) folic acid after the oral dose did not differ between the two genotypes, 424.5 +/- 140.3 (T/T) vs. 424.1+/- 202.4 h.nmol/L (C/C). There also was no significant difference in the mean cumulative 7-h urinary excretion of 5-CH(3)-H(4) folic acid between the T/T (2.5 +/- 1.4 micromol) and C/C (1.9 +/- 1.0 micromol) genotypes. Under the conditions employed, the conversion of oral 5-HCO-H(4) folic acid to 5-CH(3)-H(4) folic acid is not impaired in persons with the T/T MTHFR genotype. Possible reasons for these findings are discussed. PMID:10958818

  1. Relationship of MTHFR gene polymorphisms with renal and cardiac disease

    PubMed Central

    Trovato, Francesca M; Catalano, Daniela; Ragusa, Angela; Martines, G Fabio; Pirri, Clara; Buccheri, Maria Antonietta; Di Nora, Concetta; Trovato, Guglielmo M

    2015-01-01

    AIM: To investigate the effects of different methylenetetrahydrofolate reductase (MTHFR) 677C>T gene polymorphism and hyperhomocysteinemia for the development of renal failure and cardiovascular events, which are controversial. METHODS: We challenged the relationship, if any, of MTHFR 677C>T and MTHFR 1298A>C polymorphisms with renal and heart function. The present article is a reappraisal of these concepts, investigating within a larger population, and including a subgroup of dialysis patients, if the two most common MTHFR polymorphisms, C677T and A1298C, as homozygous, heterozygous or with a compound heterozygous state, show different association with chronic renal failure requiring hemodialysis. MTHFR polymorphism could be a favorable evolutionary factor, i.e., a protective factor for many ominous conditions, like cancer and renal failure. A similar finding was reported in fatty liver disease in which it is suggested that MTHFR polymorphisms could have maintained and maintain their persistence by an heterozygosis advantage mechanism. We studied a total of 630 Italian Caucasian subject aged 54.60 ± 16.35 years, addressing to the increased hazard of hemodialysis, if any, according to the studied MTHFR genetic polymorphisms. RESULTS: A favorable association with normal renal function of MTHFR polymorphisms, and notably of MTHFR C677T is present independently of the negative effects of left ventricular hypertrophy, increased Intra-Renal arterial Resistance and hyperparathyroidism. CONCLUSION: MTHFR gene polymorphisms could have a protective role on renal function as suggested by their lower frequency among our dialysis patients in end-stage renal failure; differently, the association with left ventricular hypertrophy and reduced left ventricular relaxation suggest some type of indirect, or concurrent mechanism. PMID:25664255

  2. Mutational analysis of the nor gene cluster which encodes nitric-oxide reductase from Paracoccus denitrificans.

    PubMed

    de Boer, A P; van der Oost, J; Reijnders, W N; Westerhoff, H V; Stouthamer, A H; van Spanning, R J

    1996-12-15

    The genes that encode the hc-type nitric-oxide reductase from Paracoccus denitrificans have been identified. They are part of a cluster of six genes (norCBQDEF) and are found near the gene cluster that encodes the cd1-type nitrite reductase, which was identified earlier [de Boer, A. P. N., Reijnders, W. N. M., Kuenen, J. G., Stouthamer, A. H. & van Spanning, R. J. M. (1994) Isolation, sequencing and mutational analysis of a gene cluster involved in nitrite reduction in Paracoccus denitrificans, Antonie Leeu wenhoek 66, 111-127]. norC and norB encode the cytochrome-c-containing subunit II and cytochrome b-containing subunit I of nitric-oxide reductase (NO reductase), respectively. norQ encodes a protein with an ATP-binding motif and has high similarity to NirQ from Pseudomonas stutzeri and Pseudomonas aeruginosa and CbbQ from Pseudomonas hydrogenothermophila. norE encodes a protein with five putative transmembrane alpha-helices and has similarity to CoxIII, the third subunit of the aa3-type cytochrome-c oxidases. norF encodes a small protein with two putative transmembrane alpha-helices. Mutagenesis of norC, norB, norQ and norD resulted in cells unable to grow anaerobically. Nitrite reductase and NO reductase (with succinate or ascorbate as substrates) and nitrous oxide reductase (with succinate as substrate) activities were not detected in these mutant strains. Nitrite extrusion was detected in the medium, indicating that nitrate reductase was active. The norQ and norD mutant strains retained about 16% and 23% of the wild-type level of NorC, respectively. The norE and norF mutant strains had specific growth rates and NorC contents similar to those of the wild-type strain, but had reduced NOR and NIR activities, indicating that their gene products are involved in regulation of enzyme activity. Mutant strains containing the norCBQDEF region on the broad-host-range vector pEG400 were able to grow anaerobically, although at a lower specific growth rate and with lower

  3. Murine diet/tissue and human brain tumorigenesis alter Mthfr/MTHFR 5'-end methylation.

    PubMed

    Lévesque, Nancy; Leclerc, Daniel; Gayden, Tenzin; Lazaris, Anthoula; De Jay, Nicolas; Petrillo, Stephanie; Metrakos, Peter; Jabado, Nada; Rozen, Rima

    2016-04-01

    Polymorphisms and decreased activity of methylenetetrahydrofolate reductase (MTHFR) are linked to disease, including cancer. However, epigenetic regulation has not been thoroughly studied. Our goal was to generate DNA methylation profiles of murine/human MTHFR gene regions and examine methylation in brain and liver tumors. Pyrosequencing in four murine tissues revealed minimal DNA methylation in the CpG island. Higher methylation was seen in liver or intestine in the CpG island shore 5' to the upstream translational start site or in another region 3' to the downstream start site. In the latter region, there was negative correlation between expression and methylation. Three orthologous regions were investigated in human MTHFR, as well as a fourth region between the two translation start sites. We found significantly increased methylation in three regions (not the CpG island) in pediatric astrocytomas compared with control brain, with decreased expression in tumors. Methylation in hepatic carcinomas was also increased in the three regions compared with normal liver, but the difference was significant for only one CpG. This work, the first overview of the Mthfr/MTHFR epigenetic landscape, suggests regulation through methylation in some regions, demonstrates increased methylation/decreased expression in pediatric astrocytomas, and should serve as a resource for future epigenetic studies. PMID:26951114

  4. Free-floating thrombus of the carotid artery with a homozygous methylenetetrahydrofolate reductase gene mutation: a case report.

    PubMed

    Colak, Necmettin; Nazli, Yunus; Kosehan, Dilek; Alpay, Mehmet Fatih; Cakir, Omer

    2013-02-01

    Free-floating thrombus (FFT) of the carotid artery is a rare condition of currently unknown etiology. We describe a symptomatic patient with an FFT in the left common carotid artery. A duplex ultrasonography scan showed the presence of a mobile floating thrombus moving in cyclical motion with the cardiac cycles in the left common carotid artery. During emergency surgery, an FFT was seen at this location and removed. No underlying wall defect was seen at the time of surgery. In a genetic screening test, TT homozygous for the methylenetetrahydrofolate reductase (MTHFR) C677T genetic polymorphisms was detected. The patient recovered uneventfully, with no neurogical events. Lifelong anticoagulant therapy was recommended. An aggressive surgical approach is recommended in the patient to prevent embolic episodes. PMID:22101856

  5. Folate intake, MTHFR genotype, and sex modulate choline metabolism in mice.

    PubMed

    Chew, Tina W; Jiang, Xinyin; Yan, Jian; Wang, Wei; Lusa, Amanda L; Carrier, Bradley J; West, Allyson A; Malysheva, Olga V; Brenna, J Thomas; Gregory, Jesse F; Caudill, Marie A

    2011-08-01

    Choline and folate are interrelated in 1-carbon metabolism, mostly because of their shared function as methyl donors for homocysteine remethylation. Folate deficiency and mutations of methylenetetrahydrofolate reductase (MTHFR) reduce the availability of a major methyl donor, 5-methyltetrahydrofolate, which in turn may lead to compensatory changes in choline metabolism. This study investigated the hypothesis that reductions in methyl group supply, either due to dietary folate deficiency or Mthfr gene deletion, would modify tissue choline metabolism in a sex-specific manner. Mthfr wild type (+/+) or heterozygous (+/-) knockout mice were randomized to a folate-deficient or control diet for 8 wk during which time deuterium-labeled choline (d9-choline) was consumed in the drinking water (~10 μmol/d). Mthfr heterozygosity did not alter brain choline metabolite concentrations, but it did enhance their labeling in males (P < 0.05) and tended to do so in females (P < 0.10), a finding consistent with greater turnover of dietary choline in brains of +/- mice. Dietary folate deficiency in females yielded 52% higher (P = 0.027) hepatic glycerophosphocholine, which suggests that phosphatidylcholine (PtdCho) degradation was enhanced. Labeling of the hepatic PtdCho in d3 form was also reduced (P < 0.001) in females, which implies that fewer of the dietary choline-derived methyl groups were used for de novo PtdCho biosynthesis under conditions of folate insufficiency. Males responded to folate restriction with a doubling (P < 0.001) of hepatic choline dehydrogenase transcripts, a finding consistent with enhanced conversion of choline to the methyl donor, betaine. Collectively, these data show that several adaptations in choline metabolism transpire as a result of mild perturbations in folate metabolism, presumably to preserve methyl group homeostasis. PMID:21697299

  6. Subacute methotrexate neurotoxicity and cerebral venous sinus thrombosis in a 12-year-old with acute lymphoblastic leukemia and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism: homocysteine-mediated methotrexate neurotoxicity via direct endothelial injury.

    PubMed

    Mahadeo, Kris M; Dhall, Girish; Panigrahy, Ashok; Lastra, Carlos; Ettinger, Lawrence J

    2010-02-01

    From as early as the 1970s methotrexate has been associated with disseminated necrotizing leukoencephalopathy and other neurotoxic sequelae. Yet, a clear mechanism for methotrexate-induced neurotoxicity has not been established. The authors describe the case of a 12-year-old male with acute lymphoblastic leukemia and a homozygous methylenetetrahydrofolate reductase C677T mutation, who developed subacute methotrexate-induced toxicity and cerebral venous thrombosis after receiving intrathecal methotrexate. The role of homocysteine as a possible mediator in methotrexate-induced neurotoxicity via direct endothelial injury is discussed. PMID:20121554

  7. The methylenetetrahydrofolate reductase C677T gene polymorphism decreases the risk of childhood acute lymphocytic leukaemia.

    PubMed

    Franco, R F; Simões, B P; Tone, L G; Gabellini, S M; Zago, M A; Falcão, R P

    2001-12-01

    We have determined the prevalence of methylenetetrahydrofolate reductase (MTHFR) mutations C677T and A1298C in 71 children (< or = 15 years) with acute lymphoblastic leukaemia (ALL) and in 71 control subjects. Odds ratio (OR) for ALL linked to MTHFR C677T was 0.4 (95% CI 0.2-0.8); for heterozygotes it was 0.5 (95% CI 0.2-0.9) and for homozygotes it was 0.3 (95%CI 0.09-0.8). MTHFR A1298C yielded an overall OR for ALL of 1.3 (95% CI: 0.7-2.6); for heterozygotes it was 1.3 (95% CI: 0.7-7.6) and for homozygotes it was 2.8 (95% CI 0.5-15.6). In conclusion, MTHFR C677T was linked to a significant 2.4-fold decreased risk of developing childhood ALL, whereas MTHFR A1298C did not significantly affect the risk of ALL in our population. PMID:11736945

  8. Plasma homocysteine levels related to interactions between folate status and methylenetetrahydrofolate reductase: a study in 52 healthy subjects.

    PubMed

    Zittoun, J; Tonetti, C; Bories, D; Pignon, J M; Tulliez, M

    1998-11-01

    Hyperhomocysteinemia, a risk factor for vascular disease, is related to vitamin B12, vitamin B6, and especially folate deficiency, or to genetic factors such as mutations in methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in the remethylation pathway of homocysteine to methionine. Recently, a C677 --> T mutation identified in the MTHFR gene was found to be frequently associated with decreased MTHFR activity and an elevated plasma homocysteine concentration. Since hyperhomocysteinemia seems to be determined by both genetic and environmental factors, we studied the interactions between MTHFR (phenotype and genotype) and folate status, including methyltetrahydrofolate (methylTHF), the product of MTHFR, on the homocysteine concentration in 52 healthy subjects, (28 women and 24 men; mean age, 32.7 years). MTHFR activity seems to be dependent on folate status, as shown by a lower activity in folate-deficient subjects and a return to normal values after supplementation with folic acid, and also by a decreased enzymatic activity on phytohemagglutinin (PHA)-stimulated lymphocytes grown in a folic acid-deficient medium. Conversely, the C677 --> T mutation seems to influence folate metabolism. Subjects who were homozygous for this mutation (+/+) had significantly higher plasma homocysteine and lower plasma folate and total and methylfolate levels in red blood cells (RBCs) than heterozygous (+/-) and normal (-/-) subjects. The ratio of RBC methylfolate to RBC total folate was, respectively, 0.27 in +/+, 0.66 in +/-, and 0.71 in -/-. This mutation seems to have an impact on methylTHF generation. These data illustrate the interactions between nutritional and genetic factors. PMID:9826223

  9. Methylenetetrahydrofolate reductase polymorphisms increase risk of esophageal squamous cell carcinoma in a Chinese population.

    PubMed

    Song, C; Xing, D; Tan, W; Wei, Q; Lin, D

    2001-04-15

    Methylenetetrahydrofolate reductase (MTHFR) plays a central role in folate metabolism that affects DNA methylation and synthesis. Because germ-line mutations at nucleotides 677 (C-->T) and 1298 (A-->C) in the MTHFR gene cause diminished enzyme activity, and aberrant DNA methylation is oncogenic, we examined the relationship between these two MTHFR polymorphisms and susceptibility to esophageal squamous cell carcinoma (ESCC) in 240 ESCC cases and 360 age- and sex-matched controls in northern CHINA: We found that the allele frequency of MTHFR 677T was significantly higher among cases than among controls (63% versus 41%, P < 0.001). Subjects with the 677TT genotype had a more than 6-fold increased risk of developing ESCC [adjusted odds ratio (OR), 6.18; 95% confidence interval (CI), 3.32-11.51] compared with those who had the 677CC genotype. Furthermore, the elevated ESCC risk associated with the 677 polymorphism was in an allele-dose relationship (trend test, P = 0.0001) with ORs of 1.00, 3.14 (95% CI, 1.94-5.08), and 6.18 (95% CI, 3.32-11.51) for the CC, CT, and TT genotype, respectively, after adjustment for age, sex, smoking status, and the MTHFR 1298 polymorphism. The allele frequency for the MTHFR 1298C was 14% among cases and 17% among controls. The 1298CC genotype was extremely rare in both controls (1.4%) and cases (2.9%) and was also associated with an elevated risk of ESCC (adjusted OR, 4.43; 95% CI, 1.23-16.02) compared with the 1298AA genotype, whereas the 1298AC genotype had no effect on the risk of ESCC. Thus, our findings support the hypothesis that genetic polymorphisms in the MTHFR gene may contribute to susceptibility to carcinogenesis of the esophagus in the at-risk Chinese population. PMID:11309278

  10. A foreign dihydrofolate reductase gene in transgenic mice acts as a dominant mutation.

    PubMed Central

    Gordon, J W

    1986-01-01

    We have produced 17 lines of transgenic mice by microinjecting a full-length cDNA clone of an altered dihydrofolate reductase (dhfr) gene. The protein specified by this gene carries a point mutation which triples its Km for dihydrofolate and reduces substrate turnover 20-fold relative to the wild-type enzyme. Transgenic mice from different pedigrees, several of which carry a single copy of this gene in different integration sites, manifest an array of similar developmental abnormalities including growth stunting, reduced fertility, pigmentation changes, and skeletal defects. These defects appear in animals heterozygous for the foreign gene. RNA analyses demonstrate significant expression of the cDNA in newborn mice and adult tissues. These findings show that the additional dhfr gene exerts its mutational effects in a dominant fashion, and therefore the data indicate that transgenic mice can serve as models for elucidating mechanisms of dominant mutagenesis. Images PMID:3785192

  11. C677T methylenetetrahydrofolate reductase and plasma homocysteine levels among Thai vegans and omnivores.

    PubMed

    Kajanachumpol, Saowanee; Atamasirikul, Kalayanee; Tantibhedhyangkul, Phieuvit

    2013-01-01

    Hyperhomocysteinemia among vegetarians and vegans is caused mostly by vitamin B12 deficiency. A C-to-T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene results in a thermolabile MTHFR, which may affect homocysteine (Hcy) levels. The importance of this gene mutation among populations depends on the T allele frequency. Blood Hcy, vitamin B12, folate, vitamin B6, and MTHFR C677T mutation status were determined in 109 vegans and 86 omnivores aged 30 - 50 years. The vegans had significantly higher Hcy levels than the omnivores, geometric means (95 % CI) 19.2 (17.0 - 21.7) µmol/L vs. 8.53 (8.12 - 8.95) µmol/L, p < 0.001. A C-to-T mutation in the vegans increased plasma Hcy, albeit insignificantly; geometric means 18.2 µmol/L, 20.4 µmol/L, and 30.0 µmol/L respectively in CC, CT, and TT MTHFR genotypes. There was also a significant decrease in serum folate; geometric means 12.1 ng/mL, 9.33 ng/mL, and 7.20 ng/mL respectively, in the CC, CT, and TT mutants, p = 0.006, and particularly, in the TT mutant compared with the CC wild type, 7.20 ng/mL vs. 12.1 ng/mL, p = 0.023. These findings were not seen in the omnivores. It was concluded that hyperhomocysteinemia is prevalent among Thai vegans due to vitamin B12 deficiency. C-to-T MTHFR mutation contributes only modestly to the hyperhomocysteinemia. PMID:24491881

  12. Polymorphism of MTHFR C677T, serum vitamin levels and cognition in subjects with hyperhomocysteinemia in China.

    PubMed

    Cheng, Dao-Mei; Jiang, Yu-Gang; Huang, Cheng-Yu; Kong, Hai-Yan; Pang, Wei; Yang, Hong-Peng

    2010-08-01

    Relationships between hyperhomocysteinemia (HHE) and neurodegenerative diseases have been widely studied. However, the impact of serum total homocysteine (tHcy) levels on cognitive function has not been confirmed. C677T polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene have impacts on tHcy level; it is suspected to influence cognitive function, but only few investigations have assessed its effects on non-dementia adults and the results have been controversial. Moreover, there is no report about Chinese subjects. In the present study, we determined C677T/MTHFR genotype, serum tHcy concentration and cognition in 182 nondemented subjects aged 55-88 years to probe the associations between MTHFRC677T mutation, increased tHcy levels and decreased cognitive function in a northern city in China. A serum tHcy level > or = 16 micromol/l was deemed HHE. Cognitive function was assessed by the Mini Mental State Examination (MMSE) and Basic Cognitive Aptitude Tests (BCAT). Results showed that: (i) subjects with the T allele had higher serum tHcy levels than those without, especially in lower folate status; (ii) T allele and CT/TT genotype frequencies in subjects with HHE were higher than in non-HHE subjects (P < 0.05); and (iii) serum tHcy level was inversely related to total BCAT score (P < 0.05) but MTHFR677 C to T polymorphism had no association with it. Our results confirmed that the MTHFR 677 C to T mutation, especially in lower serum folate concentration status, results in the increase of serum tHcy levels which is bad for cognitive function and indicates that higher serum folate level is of benefit in keeping lower serum tHcy level and better cognitive function. The results provide some valuable clues for individualized nutrition intervention of HHE and cognition decline in the middle-aged and the elderly. PMID:20670473

  13. Allelic variations in 5, 10-methylenetetrahydrofolate reductase gene and susceptibility to cervical cancer in Indian women.

    PubMed

    Nandan, Naveen Kumar; Wajid, Saima; Biswas, Shilpie; Juneja, Sominder Singh; Rizvi, Moshahid; Prakash, Raminder; Naqvi, Samar Husain

    2008-01-01

    Methylenetetrahydrofolate reductase (MTHFR) gene located on chromosome 1p36.3 catalyses the conversion of 5,10-methylenetetrahydrofolate to 5,methyltetrahydrofolate, the major methyl donor for the conversion of homocysteine to methionine. Two common polymorphisms in the MTHFR gene have been identified, 677C>T in exon 4, leading to substitution of alanine by valine and 1298A>C in exon 7 which leads to the replacement of glutamic acid by alanine resulting into reduced enzyme activity. The potential influence of MTHFR activity on DNA methylation and on the availability of uridylates and thymidylates for DNA synthesis and repair makes MTHFR an attractive candidate for cancer predisposing gene. In order to elucidate the role of MTHFR polymorphism in cervical cancer, both the exons for 677C>T and 1298A>C mutations were analyzed among 219 females, including 77 females with normal cervical cytology, 80 with cervical dysplasia and 62 with squamous cell carcinoma of uterine cervix. Females with mutant allele at 677 position (CT/TT genotypes) were found to be almost three times the risk of cervical dysplasia than females with CC genotype [OR, 2.9; (CI, 1.5-5.7)], but were less likely to develop squamous cell carcinoma [OR, 1.5 (CI, 0.7-3.2)]. Similar findings were observed for mutation at 1298 position, females with AC/CC genotypes were almost four times the risk of cervical dysplasia [OR, 4.3 (CI, 2.1-9.0)], as compared to AA genotype. Our study lends further support to the hypothesis that the MTHFR polymorphism (677C>T or 1298A>C) is involved in susceptibility to cervical dysplasia. PMID:19356065

  14. Insights into severe 5,10-methylenetetrahydrofolate reductase deficiency: molecular genetic and enzymatic characterization of 76 patients.

    PubMed

    Burda, Patricie; Schäfer, Alexandra; Suormala, Terttu; Rummel, Till; Bürer, Céline; Heuberger, Dorothea; Frapolli, Michele; Giunta, Cecilia; Sokolová, Jitka; Vlášková, Hana; Kožich, Viktor; Koch, Hans Georg; Fowler, Brian; Froese, D Sean; Baumgartner, Matthias R

    2015-06-01

    5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency is the most common inherited disorder of folate metabolism and causes severe hyperhomocysteinaemia. To better understand the relationship between mutation and function, we performed molecular genetic analysis of 76 MTHFR deficient patients, followed by extensive enzymatic characterization of fibroblasts from 72 of these. A deleterious mutation was detected on each of the 152 patient alleles, with one allele harboring two mutations. Sixty five different mutations (42 novel) were detected, including a common splicing mutation (c.1542G>A) found in 21 alleles. Using an enzyme assay in the physiological direction, we found residual activity (1.7%-42% of control) in 42 cell lines, of which 28 showed reduced affinity for nicotinamide adenine dinucleotide phosphate (NADPH), one reduced affinity for methylenetetrahydrofolate, five flavin adenine dinucleotide-responsiveness, and 24 abnormal kinetics of S-adenosylmethionine inhibition. Missense mutations causing virtually absent activity were found exclusively in the N-terminal catalytic domain, whereas missense mutations in the C-terminal regulatory domain caused decreased NADPH binding and disturbed inhibition by S-adenosylmethionine. Characterization of patients in this way provides a basis for improved diagnosis using expanded enzymatic criteria, increases understanding of the molecular basis of MTHFR dysfunction, and points to the possible role of cofactor or substrate in the treatment of patients with specific mutations. PMID:25736335

  15. MTHFR C677T polymorphism as a risk factor of neural tube defects in Malay: a case control study.

    PubMed

    Hayati, A R; Zainal, A I; Tan, G C; Ong, L C; Khoo, T B

    2008-12-01

    Major congenital malformations occur in about 3% of newborn. Several studies have suggested that homozygosity for the C677T methylenetetrahydrofolate reductase (MTHFR) variant is a potential risk factor for neural tube defects (NTDs). It has been hypothesized that the maternal folic acid supplementation prevents NTDs by partially correcting reduced MTHFR activity associated with the variant form of the enzyme. This association has not been found in some ethnic groups. In this study, we attempted to assess the association between NTDs and MTHFR C677T in Malaysian Malay population. Results show that MTHFR 677TT genotype was absent in both patient and control groups. PMID:19803295

  16. Thioredoxin Reductase 2 (TXNRD2) Mutation Associated With Familial Glucocorticoid Deficiency (FGD)

    PubMed Central

    Prasad, Rathi; Chan, Li F.; Hughes, Claire R.; Kaski, Juan P.; Kowalczyk, Julia C.; Savage, Martin O.; Peters, Catherine J.; Nathwani, Nisha; Clark, Adrian J. L.; Metherell, Louise A.

    2014-01-01

    Context: Classic ACTH resistance, due to disruption of ACTH signaling, accounts for the majority of cases of familial glucocorticoid deficiency (FGD). Recently FGD cases caused by mutations in the mitochondrial antioxidant, nicotinamide nucleotide transhydrogenase, have highlighted the importance of redox regulation in steroidogenesis. Objective: We hypothesized that other components of mitochondrial antioxidant systems would be good candidates in the etiology of FGD. Design: Whole-exome sequencing was performed on three related patients, and segregation of putative causal variants confirmed by Sanger sequencing of all family members. A TXNRD2-knockdown H295R cell line was created to investigate redox homeostasis. Setting: The study was conducted on patients from three pediatric centers in the United Kingdom. Patients: Seven individuals from a consanguineous Kashmiri kindred, six of whom presented with FGD between 0.1 and 10.8 years, participated in the study. Interventions: There were no interventions. Main Outcome Measure: Identification and functional interrogation of a novel homozygous mutation segregating with the disease trait were measured. Results: A stop gain mutation, p.Y447X in TXNRD2, encoding the mitochondrial selenoprotein thioredoxin reductase 2 (TXNRD2) was identified and segregated with disease in this extended kindred. RT-PCR and Western blotting revealed complete absence of TXNRD2 in patients homozygous for the mutation. TXNRD2 deficiency leads to impaired redox homeostasis in a human adrenocortical cell line. Conclusion: In contrast to the Txnrd2-knockout mouse model, in which embryonic lethality as a consequence of hematopoietic and cardiac defects is described, absence of TXNRD2 in humans leads to glucocorticoid deficiency. This is the first report of a homozygous mutation in any component of the thioredoxin antioxidant system leading to inherited disease in humans. PMID:24601690

  17. A transgenic Neospora caninum strain based on mutations of the dihydrofolate reductase-thymidylate synthase gene.

    PubMed

    Pereira, Luiz Miguel; Baroni, Luciana; Yatsuda, Ana Patrícia

    2014-03-01

    Neospora caninum is an Apicomplexa parasite related to abortion and losses of fertility in cattle. The amenability of Toxoplasma gondii and Plasmodium to genetic manipulation offers several tools to determine the invasion and replication processes, which support posterior strategies related to the combat of these diseases. For Plasmodium the use of pyrimethamine as an auxiliary drug on malaria treatment has been affected by the rise of resistant strains and the analyses on Dihydrofolate reductase-thymidylate synthase (DHFR-TS) gene indicated several point mutations. In this work we developed a method for stable insertion of genes based on resistance to pyrimethamine. For that, the coding sequence of NcDHFR-TS (Dihydrofolate reductase-thymidylate synthase) was point mutated in two amino acids, generating DHFRM2M3. The DHFRM2M3 flanked by the promoter and 3'UTR of Ncdhfr-ts (Ncdhfr-DHFRM2M3) conferred resistance to pyrimethamine after transfection. For illustration of stability and expression, the cassette Ncdhfr-DHFRM2M3 was ligated to the reporter gene Lac-Z (β-galactosidase enzyme) controlled by the N. caninum tubulin promoter and was transfected and selected in N. caninum. The cassette was integrated into the genome and the selected tachyzoites expressed Lac-Z, allowing the detection of tachyzoites by the CPRG reaction and X-gal precipitation. The obtainment of transgenic N. caninum resistant to pyrimethamine confirms the effects on DHFR-TS among the Apicomplexa members and will support future approaches on pholate inhibitors for N. caninum prophylaxis. The construction of stable tachyzoites based on vectors with N. caninum promoters initiates the molecular manipulation of this parasite independently of T. gondii. PMID:24440296

  18. Impact of thrombophilic genes mutations on thrombosis risk in Egyptian nonmetastatic cancer patients.

    PubMed

    Wahba, Mona Ahmed; Ismail, Mona Ahmed; Saad, Abeer Attia; Habashy, Deena Mohamed; Hafeez, Zeinab Mohamed Abdel; Boshnak, Noha Hussein

    2015-04-01

    Venous thromboembolism (VTE) is a common complication in cancer patients. Several genetic risk factors related to thrombophilia are known; however, their contributions to thrombotic tendency in cancer patients have conflicting results. We aimed to determine the prevalence of factor V Leiden (FVL), prothrombin (PTH) G20210A and methylene tetrahydrofolate reductase (MTHFR) C677T gene polymorphisms in Egyptian nonmetastatic cancer patients and their influence on thrombosis risk in those patients. Factor V Leiden, PTH G20210A and MTHFR C677T polymorphisms were detected in 40 cancer patients with VTE (group 1) and 40 cancer patients with no evidence of VTE (group 2) by PCR-based DNA analysis. Factor V and MTHFR mutations were higher in group 1 than in group 2 (factor V heterozygous mutation: 20 vs. 7.5%, homozygous mutation: 10 vs. 2.5%; MTHFR heterozygous mutation: 40 vs. 25%, homozygous mutation 5 vs. 0%, respectively) (P = 0.03). Mortality rate was higher in group 1 (75%) than in group 2 (25%; P < 0.001). No difference was found between those groups regarding PTH mutation (P = 1). Mortality rate was higher in the presence of homozygous and heterozygous factor V mutation (100 and 82%, respectively) compared to the wild type (41%) (P = 0.0006). Having any of the three studied gene mutations worsened the overall survival (P = 0.0003). Cox regression proved that both thrombosis and presence of factor V mutation are independent factors affecting survival in cancer patients (P < 0.001 and P = 0.01, respectively). In conclusion, there is an association between factor V and MTHFR mutations and risk of VTE in Egyptian cancer patients. Thrombosis and presence of factor V mutation are independent factors that influence survival in those patients. PMID:25565385

  19. Association of MTHFR genetic polymorphisms with venous thromboembolism in Uyghur population in Xinjiang, China

    PubMed Central

    Li, Zhao; Yadav, Umesh; Mahemuti, Ailiman; Tang, Bao-Peng; Upur, Halmurat

    2015-01-01

    Background: The aim of this study was to reveal the association between Methylene tetrahydrofolate reductase (MTHFR) gene mutations (C677T, A1298C and C1317T) and risk of venous thromboembolism (VTE) in Han and Uyghur population in Xinjiang. Material and method: We conducted a case control study composed of 246 cases, including 86 Uyghur and 160 Han ethnic diagnosed VTE were admitted in the First Affiliated Hospital of Xinjiang Medical University between January 2008 to December 2012, and 292 population including 122 Uyghur ethnic and 170 Han ethnic were studied as controls. To detect the polymorphism of MTHFR gene C677T, A1298T, and C1317T, Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was applied. Fluorescence polarization immunoassay was adopted to determine the plasma levels Homocysteine (Hcy), folic acid and vitaminB12 (VitB12). The association of the polymorphism of MTHFR and levels Hcy, folic acid and VitB12 with VTE was analyzed. Results: The MTHFR gene C677T genotypes distribution in Uyghur VTE patients and control groups were: TT (27.91% vs. 12.29%), CT (41.86% vs. 52.46%) and CC (30.23% vs. 35.25%), respectively; and in Han VTE patients and control groups were: TT (27.49% vs. 14.71%), CT (44.38% vs. 53.53%) and CC (28.13% vs. 31.76%), respectively, and there were significant differences in TT genotype of MTHFRC677T between VTE patients and controls in both Uyghur and Han ethnic (Uyghur: x2=8.070, P=0.005; Han: x2=8.159, P=0.004). However, there were no significant differences in the MTHFR gene A1298T and C1317T genotyping distribution frequency in Uygur and Han ethnic between VTE patients and controls (P>0.05). Plasma levels of Hcy in MTHFR gene TT genotype were statistically higher than CT and CC genotype (P<0.05). After adjusting for age, gender, smoking, hypertension, hyperlipidemia, diabetes and MTHFR genotype for plasma Hcy levels, multifactor logistic regression analysis showed (OR=1.025, 95% CI 1.003-1.046, P=0

  20. [Resistance to acenocoumarol revealing a missense mutation of the vitamin K epoxyde reductase VKORC1: a case report].

    PubMed

    Mboup, M C; Dia, K; Ba, D M; Fall, P D

    2015-02-01

    A significant proportion of the interindividual variability of the response to vitamin K antagonist (VKA) treatment has been associated with genetic factors. Genetic variations affecting the vitamin K epoxide reductase complex subunit 1 (VKORC1) are associated with hypersensitivity or rarely with resistance to VKA. We report the case of a black women patient who presents a resistance to acenocoumarol. Despite the use of high doses of acenocoumarol (114 mg/week) for the treatment of recurrent pulmonary embolism, the International Normalized Ratio was below the therapeutic target. This resistance to acenocoumarol was confirmed by the identification of a missense mutation Val66Met of the vitamin K epoxide reductase. PMID:24095214

  1. Hydride transfer catalysed by Escherichia coli and Bacillus subtilis dihydrofolate reductase: coupled motions and distal mutations.

    PubMed

    Hammes-Schiffer, Sharon; Watney, James B

    2006-08-29

    This paper reviews the results from hybrid quantum/classical molecular dynamics simulations of the hydride transfer reaction catalysed by wild-type (WT) and mutant Escherichia coli and WT Bacillus subtilis dihydrofolate reductase (DHFR). Nuclear quantum effects such as zero point energy and hydrogen tunnelling are significant in these reactions and substantially decrease the free energy barrier. The donor-acceptor distance decreases to ca 2.7 A at transition-state configurations to enable the hydride transfer. A network of coupled motions representing conformational changes along the collective reaction coordinate facilitates the hydride transfer reaction by decreasing the donor-acceptor distance and providing a favourable geometric and electrostatic environment. Recent single-molecule experiments confirm that at least some of these thermally averaged equilibrium conformational changes occur on the millisecond time-scale of the hydride transfer. Distal mutations can lead to non-local structural changes and significantly impact the probability of sampling configurations conducive to the hydride transfer, thereby altering the free-energy barrier and the rate of hydride transfer. E. coli and B. subtilis DHFR enzymes, which have similar tertiary structures and hydride transfer rates with 44% sequence identity, exhibit both similarities and differences in the equilibrium motions and conformational changes correlated to hydride transfer, suggesting a balance of conservation and flexibility across species. PMID:16873124

  2. Association between the thrombophilic polymorphisms MTHFR C677T, Factor V Leiden, and prothrombin G20210A and recurrent miscarriage in Brazilian women.

    PubMed

    Gonçalves, R O; Fraga, L R; Santos, W V B; Carvalho, A F L; Veloso Cerqueira, B A V; Sarno, M; Toralles, M B P; Vieira, M J; Dutra, C G; Schüler-Faccini, L; Sanseverino, M T V; Gonçalves, M S; Vianna, F S L; Costa, O L N

    2016-01-01

    Some cases of recurrent first trimester miscarriage have a thrombotic etiology. The aim of this study was to investigate the prevalence of the most common thrombophilic mutations - factor V (FV) Leiden G1691A (FVL), prothrombin (FII) G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T - in women with recurrent miscarriages. In this case-control study, we included 137 women with two or more consecutive first-trimester miscarriages (£12 weeks of gestation) and 100 healthy women with no history of pregnancy loss, and with at least one living child. DNA was extracted from the patient samples, and the relevant genes (FVL, FII, and MTHFR) were amplified by PCR, followed by restriction fragment length polymorphism, to assess the polymorphisms in these genes. The allelic frequencies of polymorphisms were not significantly different between the case and control groups. Polymorphisms in the MTHFR, FVL, and FII genes were not associated with recurrent miscarriage during the first trimester of pregnancy in Brazilian women (P = 0.479; P = 0.491 and P = 0.107, respectively). However, the etiologic identification of genetic factors is important for genetic counseling. PMID:27525841

  3. Altered heme catabolism by heme oxygenase-1 caused by mutations in human NADPH cytochrome P450 reductase

    SciTech Connect

    Pandey, Amit V.; Flueck, Christa E.; Mullis, Primus E.

    2010-09-24

    Research highlights: {yields} Mutations in POR identified from patients lead to reduced HO-1 activities. {yields} POR mutation Y181D affecting FMN binding results in total loss of HO-1 activity. {yields} POR mutations A287P, C569Y and V608F, lost 50-70% activity. {yields} Mutations in FAD binding domain, R457H, Y459H and V492E lost all HO-1 activity. {yields} POR polymorphisms P228L, R316W, G413S, A503V and G504R have normal activity. -- Abstract: Human heme oxygenase-1 (HO-1) carries out heme catabolism supported by electrons supplied from the NADPH through NADPH P450 reductase (POR, CPR). Previously we have shown that mutations in human POR cause a rare form of congenital adrenal hyperplasia. In this study, we have evaluated the effects of mutations in POR on HO-1 activity. We used purified preparations of wild type and mutant human POR and in vitro reconstitution with purified HO-1 to measure heme degradation in a coupled assay using biliverdin reductase. Here we show that mutations in POR found in patients may reduce HO-1 activity, potentially influencing heme catabolism in individuals carrying mutant POR alleles. POR mutants Y181D, A457H, Y459H, V492E and R616X had total loss of HO-1 activity, while POR mutations A287P, C569Y and V608F lost 50-70% activity. The POR variants P228L, R316W and G413S, A503V and G504R identified as polymorphs had close to WT activity. Loss of HO-1 activity may result in increased oxidative neurotoxicity, anemia, growth retardation and iron deposition. Further examination of patients affected with POR deficiency will be required to assess the metabolic effects of reduced HO-1 activity in affected individuals.

  4. Genetic and epigenetic variants in the MTHFR gene are not associated with non-Hodgkin lymphoma

    PubMed Central

    Bradshaw, Gabrielle; Sutherland, Heidi G.; Camilleri, Emily T.; Lea, Rodney A.; Haupt, Larisa M.; Griffiths, Lyn R.

    2015-01-01

    The methylenetetrahydrofolate reductase (MTHFR) gene codes for the MTHFR enzyme which plays a key role in the pathway of folate and methionine metabolism. Polymorphisms of genes in this pathway affect its regulation and have been linked to lymphoma. In this study we examined whether we could detect an association between two common non-synonymous MTHFR polymorphisms, 677C > T (rs1801133) and 1298A > C (rs1801131), and susceptibility to non-Hodgkin lymphoma (NHL) in an Australian case–control cohort. We found no significant differences between genotype or allele frequencies for either polymorphisms between lymphoma cases and controls. We also explored whether epigenetic modification of MTHFR, specifically DNA methylation of a CpG island in the MTHFR promoter region, is associated with NHL using blood samples from patients. No difference in methylation levels was detected between the case and control samples suggesting that although hypermethylation of MTHFR has been reported in tumour tissues, particularly in the diffuse large B-cell lymphoma subtype of NHL, methylation of this MTHFR promoter CpG island is not a suitable epigenetic biomarker for NHL diagnosis or prognosis in peripheral blood samples. Further studies into epigenetic variants could focus on genes that are robustly associated with NHL susceptibility. PMID:26629414

  5. Dihydrofolate reductase mutations and chromosomal changes associated with pyrimethamine resistance of Plasmodium falciparum.

    PubMed

    Tanaka, M; Gu, H M; Bzik, D J; Li, W B; Inselburg, J W

    1990-02-01

    The nucleotide sequence of the dihydrofolate reductase-thymidylate synthase (DHFR-TS) gene in pyrimethamine-resistant (PyrR) mutants of Plasmodium falciparum selected in vitro was examined to determine if specific mutations in DHFR were associated with drug resistance. We analysed the sequence of genomic DNA from strain FCR3, from eight previously isolated PyrR parasites derived from FCR3, and from strain Honduras-1. We found that: (1) five PyrR FCR3 mutants, FCR3-D4-D8, had an identical nucleotide change and a novel single amino acid change (Phe to Ser) at amino acid 223 of DHFR; (2) our originally reported nucleotide sequence of the DHFR-TS gene was of the PyrR strain Honduras-1, and was not of FCR3; (3) three PyrR mutants, FCR3-D1, D2, and D3, thought to have been derived from the FCR3 strain, were in fact isolates of Honduras-1. We also examined the chromosomal DNA of PyrR mutants by pulsed-field gradient gel (PFG) electrophoresis. The PyrR mutants FCR3-D1, D2, and D3 had several chromosome size polymorphisms compared to FCR3. In two of the PyrR FCR3 mutants, FCR3-D7 and D8, the chromosome 4-size DNA of FCR3 that the DHFR-TS probe normally hybridised to was not observed. Instead, in FCR3-D7, a chromosome larger than the chromosome 4-size DNA was observed to hybridise to the DHFR-TS probe. In FCR3-D8, two chromosomes that hybridised to the DHFR-TS probe were found. One of them was larger than FCR-3 chromosome 4-size DNA, and the other was smaller than FCR3 chromosome 1-size DNA.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2406591

  6. [Posterior-predominant leukoencephalopathy which was caused by methylenetetrahydrofolate reductase deficiency and successfully treated with folic acid].

    PubMed

    Tamura, Asako; Sasaki, Ryogen; Kagawa, Ken; Nakatani, Kaname; Osaka, Hitoshi; Tomimoto, Hidekazu

    2014-01-01

    A 35-year-old woman was admitted with subacute intellectual deterioration. Laboratory studies showed elevated total homocysteine and decreased folic acid. MRI revealed leukoencephalopathy with a posterior predominance, and hyperintensity in the pyramidal tracts on T2-weighted and FLAIR images. The enzyme assay showed a deficiency of methylenetetrahydrofolate reductase (MTHFR) activity with low residual activity of 4.2% of the mean control value in cultured fibroblasts. Sequence analysis of the MTHFR gene demonstrated two homozygous missense mutations, c.677C>T (p.Ala222Val) and c.685A>C (p.Ile225Leu). c.677C>T (p.Ala222Val) is known as a common polymorphism and c.685A>C (p.Ile225Leu) is considered to be a novel polymorphism. A diagnosis of MTHFR deficiency was made. Treatment with folic acid, vitamin B12 and B6 made significant improvement of intellectual deterioration and reduction in the total homocysteine level. They also made marked resolution of leukoencephalopathy. Posterior-predominant leukoencephalopathy was found to be an excellent marker of MTHFR deficiency, and may help to establish the diagnosis. PMID:24705833

  7. Congenital Recessive Methemoglobinemia Revealed in Adulthood: Description of a New Mutation in Cytochrome b5 Reductase Gene.

    PubMed

    Forestier, Alexandra; Pissard, Serge; Cretet, Justine; Mambie, Adeline; Pascal, Laurent; Cliquennois, Manuel; Cambier, Nathalie; Rose, Christian

    2015-01-01

    Methemoglobinemia can be acquired (oxidizing drugs or chemicals products) or inherited either by mutations affecting globin chains [M hemoglobins (M Hbs)] or by defects in the enzymatic system involved in the reduction of spontaneous Hb oxidation: nicotinamide adenine dinucleotide (NADH)-cytochrome b5 reductase. It is encoded by the CYB5R3 gene: there are two phenotypes of autosomal recessive congenital methemoglobinemia, in type II CYB5R deficiency is generalized and affects all cells, leading to an early onset, whereas in type I, the enzyme deficiency is restricted to erythrocytes, usually discovered in infancy but not exclusively. We report a new case of methemoglobinemia discovered in a patient from Bahrain who exhibited an unknown dyspnea at the age of 37 years without trigger events or oxidizing products. We discovered a new mutation in the CYB5R3 gene: exon 9, codon 266 (delGAG) (GLU) (CYB5R3: c.726_729delGAG) in the homozygous state. Appearance of methemoglobinemia in an adult usually suggests an acquired cause but our case illustrated that it could also reveal a type I mutation of cytochrome b5 reductase. PMID:26291966

  8. Factor V Leiden, factor V Cambridge, factor II GA20210, and methylenetetrahydrofolate reductase in cerebral venous and sinus thrombosis: A case-control study

    PubMed Central

    Saadatnia, Mohammad; Salehi, Mansour; Movahedian, Ahmad; Shariat, Seyed Ziaeddin Samsam; Salari, Mehri; Tajmirriahi, Marzieh; Asadimobarakeh, Elham; Salehi, Rasoul; Amini, Gilda; Ebrahimi, Homa; Kheradmand, Ehsan

    2015-01-01

    Background: Factor V G1691A (FV Leiden), FII GA20210, and methylenetetrahydrofolate reductase (MTHFR) C677T mutations are the most common genetic risk factors for thromboembolism in the Western countries. However, there is rare data in Iran about cerebral venous and sinus thrombosis (CVST) patients. The aim of this study was to evaluate the frequency of common genetic thrombophilic factors in CVST patients. Materials and Methods: Forty consequently CVST patients from two University Hospital in Isfahan University of Medical Sciences aged more than 15 years from January 2009 to January 2011 were recruited. In parallel, 51 healthy subjects with the same age and race from similar population selected as controls. FV Leiden, FII GA20210, MTHFR C677T, and FV Cambridge gene mutations by polymerase chain reaction technique were evaluated in case and control groups. Results: FV Leiden, FII GA20210, and FV Cambridge gene mutations had very low prevalence in both case (5%, 2%, 0%) and control (2.5%, 0%, 0%) and were not found any significant difference between groups. MTHFR C677T mutations was in 22 (55%) of patients in case group and 18 (35.5%) of control group (P = 0.09). Conclusion: This study showed that the prevalence of FV Leiden, FII GA20210, and FV Cambridge were low. Laboratory investigations of these mutations as a routine test for all patients with CVST may not be cost benefit. PMID:26600830

  9. Population- and Family-Based Studies Associate the "MTHFR" Gene with Idiopathic Autism in Simplex Families

    ERIC Educational Resources Information Center

    Liu, Xudong; Solehdin, Fatima; Cohen, Ira L.; Gonzalez, Maripaz G.; Jenkins, Edmund C.; Lewis, M. E. Suzanne; Holden, Jeanette J. A.

    2011-01-01

    Two methylenetetrahydrofolate reductase gene ("MTHFR") functional polymorphisms were studied in 205 North American simplex (SPX) and 307 multiplex (MPX) families having one or more children with an autism spectrum disorder. Case-control comparisons revealed a significantly higher frequency of the low-activity 677T allele, higher prevalence of the…

  10. Staying green postharvest: how three mutations in the Arabidopsis chlorophyll b reductase gene NYC1 delay degreening by distinct mechanisms.

    PubMed

    Jibran, Rubina; Sullivan, Kerry L; Crowhurst, Ross; Erridge, Zoe A; Chagné, David; McLachlan, Andrew R G; Brummell, David A; Dijkwel, Paul P; Hunter, Donald A

    2015-11-01

    Stresses such as energy deprivation, wounding and water-supply disruption often contribute to rapid deterioration of harvested tissues. To uncover the genetic regulation behind such stresses, a simple assessment system was used to detect senescence mutants in conjunction with two rapid mapping techniques to identify the causal mutations. To demonstrate the power of this approach, immature inflorescences of Arabidopsis plants that contained ethyl methanesulfonate-induced lesions were detached and screened for altered timing of dark-induced senescence. Numerous mutant lines displaying accelerated or delayed timing of senescence relative to wild type were discovered. The underlying mutations in three of these were identified using High Resolution Melting analysis to map to a chromosomal arm followed by a whole-genome sequencing-based mapping method, termed 'Needle in the K-Stack', to identify the causal lesions. All three mutations were single base pair changes and occurred in the same gene, NON-YELLOW COLORING1 (NYC1), a chlorophyll b reductase of the short-chain dehydrogenase/reductase (SDR) superfamily. This was consistent with the mutants preferentially retaining chlorophyll b, although substantial amounts of chlorophyll b were still lost. The single base pair mutations disrupted NYC1 function by three distinct mechanisms, one by producing a termination codon, the second by interfering with correct intron splicing and the third by replacing a highly conserved proline with a non-equivalent serine residue. This non-synonymous amino acid change, which occurred in the NADPH binding domain of NYC1, is the first example of such a mutation in an SDR protein inhibiting a physiological response in plants. PMID:26261268

  11. Influence of 5,10-methylenetetrahydrofolate reductase gene polymorphism on plasma homocysteine concentration in patients with end-stage renal disease.

    PubMed

    Lee, H A; Choi, J S; Ha, K S; Yang, D H; Chang, S K; Hong, S Y

    1999-08-01

    The purpose of this study is to observe the influence of the methylenetetrahydrofolate reductase (MTHFR) gene (677C-->T substitution) on plasma homocysteine levels in end-stage renal disease (ESRD) patients who received a relatively large amount of folate (2 mg/d) and are undergoing hemodialysis. A cross-sectional study of plasma homocysteine, vitamin B(12), and folate was performed in patients with ESRD. The study population for the MTHFR gene study included 312 healthy subjects and 106 patients with ESRD undergoing hemodialysis. The C677T transition in the MTHFR gene was detected by HinF 1 restriction enzyme analysis and subsequent electrophoresis in a 3% agarose gel. The genotype of the MTHFR gene in 106 patients with ESRD was homozygous C677T mutation (VV) in 17 patients (16.1%) and heterozygous (AV) in 63 patients (58.4%); 26 patients (24.5%) did not carry this mutation (AA). The mean levels of homocysteine, vitamin B(12), and folate in the patients with ESRD were 23.3 +/- 14.0 mmol/L, 620.2 +/- 98.5 pmol/L, and 138.6 +/- 55.6 nmol/L, respectively. There was no significant difference in homocysteine levels among the three genotypes: 28.2 +/- 19.4 mmol/L for VV, 22.7 +/- 14.9 mmol/L for AV, and 23.4 +/- 11.1 mmol/L for AA genotype (P > 0.05). There was no difference in genotype distribution between the patient groups of less than 25th and greater than 75th percentiles, classified according to plasma homocysteine levels (P = 0.47). In conclusion, with high-dose folate supplementation, the hyperhomocysteinemia in patients with ESRD does not seem to be caused by the 677C-->T mutation in the MTHFR gene. PMID:10430972

  12. Hyperhomocysteinemia-induced upper extremity deep vein thrombosis and pulmonary embolism in a patient with methyltetrahydrofolate reductase mutation: a case report and literature review.

    PubMed

    Gao, Lin; Kolanuvada, Bangaruraju; Naik, Geetha; Zhang, Yingzhong; Zhao, Min; Sun, Lili; Alaie, Dariush; Petrillo, Richard L

    2016-09-01

    The study highlights pulmonary embolism and deep vein thrombosis by methylene tetrahydrofolate reductase (MTHFR) deficiency-related hyperhomocysteinemia occurring in rare locations of left veins superior to the heart extensively. A 59-year-old white man with history of leg pain, smoking, weight loss, benign prostatic hyperplasia, lipoma and panic attack presented with shortness of breath and chest pain for 2 days precipitated by not feeling well for months. The diagnostic workup revealed pulmonary embolism and deep vein thrombosis in the left subclavian vein which extended throughout the left brachiocephalic vein to the superior vena cava and left jugular vein. Further workup showed moderate hyperhomocysteinemia with normal levels of vitamin B6, B12 and folic acid. Methylene tetrahydrofolate reductase genetic study found the patient to be homozygous for G677T variant. He was started on low-molecular-weight heparin and was discharged on oral anticoagulant. No recurrent thrombotic episodes were witnessed after 4 months of follow-up after discharge. PMID:26650456

  13. Association of the MTHFR A1298C Variant with Unexplained Severe Male Infertility

    PubMed Central

    Eloualid, Abdelmajid; Abidi, Omar; Charif, Majida; El houate, Brahim; Benrahma, Houda; Louanjli, Noureddine; Chadli, Elbakkay; Ajjemami, Maria; Barakat, Abdelhamid; Bashamboo, Anu; McElreavey, Ken; Rhaissi, Houria; Rouba, Hassan

    2012-01-01

    The methylenetetrahydrofolate reductase (MTHFR) gene is one of the main regulatory enzymes involved in folate metabolism, DNA synthesis and remethylation reactions. The influence of MTHFR variants on male infertility is not completely understood. The objective of this study was to analyze the distribution of the MTHFR C677T and A1298C variants using PCR-Restriction Fragment Length Polymorphism (RFLP) in a case group consisting of 344 men with unexplained reduced sperm counts compared to 617 ancestry-matched fertile or normozoospermic controls. The Chi square test was used to analyze the genotype distributions of MTHFR polymorphisms. Our data indicated a lack of association of the C677T variant with infertility. However, the homozygous (C/C) A1298C polymorphism of the MTHFR gene was present at a statistically high significance in severe oligozoospermia group compared with controls (OR = 3.372, 95% confidence interval CI = 1.27–8.238; p = 0.01431). The genotype distribution of the A1298C variants showed significant deviation from the expected Hardy-Weinberg equilibrium, suggesting that purifying selection may be acting on the 1298CC genotype. Further studies are necessary to determine the influence of the environment, especially the consumption of diet folate on sperm counts of men with different MTHFR variants. PMID:22457816

  14. Genetic variations in MTHFR and gastric cardia adenocarcinoma susceptibility in the Chinese Han population

    PubMed Central

    Wang, Yafeng; Chen, Shuchen; Kang, Mingqiang; Tang, Weifeng; Gu, Haiyong; Yin, Jun; Huang, Ziyang

    2015-01-01

    Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms are associated with many types of cancers. The purpose of our study was to evaluate the effect of MTHFR single nucleotide polymorphisms (SNPs) on gastric cardia adenocarcinoma (GCA). We conducted a hospital-based case-control study. Three hundred and thirty cases with GCA and 608 controls were recruited. The ligation detection reaction (LDR) method was used to determine genotypes. The genotype MTHFR rs1801133 TT was significantly more frequent in cases than in controls (adjusted odds ratio (OR) = 1.46, 95% confidence interval (CI) = 1.04-2.05, P = 0.029) in a recessive model, after adjusting for age, sex and smoking and alcohol use. The haplotype MTHFR Grs4845882Ars4846048Trs1801133Crs9651118Ars3753584 was more frequent in cases than in controls (crude OR = 5.32, 95% CI = 2.34-12.10, P < 0.001). No association between other genotypes and haplotypes was observed. Our results suggest that the genotype MTHFR rs1801133 TT and the MTHFR Grs4845882Ars4846048Trs1801133Crs9651118Ars3753584 haplotype may be associated with susceptibility to GCA. Further studies are needed to confirm these findings. PMID:26770518

  15. Ramifications of four concurrent thrombophilic mutations and one hypofibrinolytic mutation.

    PubMed

    Glueck, Charles J; Goldenberg, Naila; Wang, Ping; Aregawi, Dawit

    2004-10-01

    A kindred was examined in which the 48-year-old white female proband with three deep venous thrombosis-pulmonary emboli events had four thrombophilic and one hypofibrinolytic mutations, and in which her 14-year-old asymptomatic daughter had four thrombophilic mutations. The proband was heterozygous for the G1691A factor V Leiden, G20210A prothrombin, and platelet glycoprotein IIIa PL A1/A2 mutations, had high factor VIII (221%), and was homozygous for the 4G4G plasminogen activator inhibitor-1 gene mutation, with high plasminogen activator inhibitor activity (23.7 U/mL). Her 14-year-old daughter was homozygous for the G1691A factor V Leiden and platelet glycoprotein IIb-IIIa PL A2/A2 mutations, compound heterozygous for the C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) mutations, and heterozygous for the G20210A prothrombin mutation, a combination with an estimated likelihood of 1.6 x 10(-7). In 247 white healthy controls, there was no V Leiden homozygosity and no V Leiden-prothrombin gene compound heterozygosity. Heterozygosity for the V Leiden and prothrombin gene mutations was 3.2% and 4.1%, respectively. Homozygosity for the platelet glycoprotein IIb-IIIa PL A2A2, PAI-1 gene 4G4G, and C677T MTHFR mutations was 3.2%, 22.7%, and 12%, respectively. The proband will receive anticoagulation therapy for life. Beyond aspirin, avoidance of exogenous estrogens, and enoxaparin prophylaxis during pregnancy, it is not known whether the proband's daughter should have lifelong anticoagulation therapy, or only after her first thrombotic event. PMID:15497023

  16. 5,10 Methylenetetrahydrofolate reductase genetic polymorphism as a risk factor for neural tube defects

    SciTech Connect

    Ou, C.Y.; Brown, V.K.; Khoury, M.J.

    1996-06-28

    Persons with a thermolabile form of the enzyme 5,10 methylenetetrahydrofolate reductase (MTHFR) have reduced enzyme activity and increased plasma homocysteine which can be lowered by supplemental folic acid. Thermolability of the enzyme has recently been shown to be caused by a common mutation (677C{sup {r_arrow}}T) in the MTHFR gene. We studied 41 fibroblast cultures from NTD-affected fetuses and compared their genotypes with those of 109 blood specimens from individuals in the general population. 677C{sup {r_arrow}}T homozygosity was associated with a 7.2 fold increased risk for NTDs (95% confidence interval: 1.8-30.3; p value: 0.001). These preliminary data suggest that the 677C{sup {r_arrow}}T polymorphism of the MTHFR gene is a risk factor for spina bifida and anencephaly that may provide a partial biologic explanation for why folic acid prevents these types of NTD. 13 refs., 1 fig., 1 tab.

  17. The C677T mutation in the methylenetetrahydrofolate reductase gene predisposes to hyperhomocysteinemia in children with familial hypercholesterolemia treated with cholestyramine.

    PubMed

    Tonstad, S; Refsum, H; Ose, L; Ueland, P M

    1998-02-01

    In children with familial hypercholesterolemia, heterozygosity and homozygosity for the C677T mutation in the methylenetetrahydrofolate reductase gene was associated with low serum folate and increased susceptibility to elevation of plasma total homocysteine during cholestyramine treatment. Because of the independent relationship between elevated plasma total homocysteine and cardiovascular disease, folate supplementation may be prudent in these children. PMID:9506661

  18. Identification by mutational analysis of four critical residues in the molybdenum cofactor domain of eukaryotic nitrate reductase.

    PubMed

    Meyer, C; Gonneau, M; Caboche, M; Rouzé, P

    1995-08-21

    The nucleotide sequence of the nitrate reductase (NR) molybdenum cofactor (MoCo) domain was determined in four Nicotiana plumbaginifolia mutants affected in the NR apoenzyme gene. In each case, missense mutations were found in the MoCo domain which affected amino acids that were conserved not only among eukaryotic NRs but also in animal sulfite oxidase sequences. Moreover an abnormal NR molecular mass was observed in three mutants, suggesting that the integrity of the MoCo domain is essential for a proper assembly of holo-NR. These data allowed to pinpoint critical residues in the NR MoCo domain necessary for the enzyme activity but also important for its quaternary structure. PMID:7656976

  19. Geographical and Ethnic Distributions of the MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in Chinese Populations: A Meta-Analysis

    PubMed Central

    Zeng, Dingyuan

    2016-01-01

    Background The geographical and ethnic distributions of the polymorphic methylenetetrahydrofolate reductase (MTHFR) mutations (C677T and A1298C) and methionine synthase reductase (MTRR) mutation (A66G) remain heterogeneous in China. The goal of this study was to estimate the pooled frequencies of the alleles and associated genotypes of these gene polymorphisms among healthy populations in Mainland China. Objective and Methods We systematically reviewed published epidemiological studies on the distributions of 3 genetic variants in Chinese healthy populations living in Mainland China through a meta-analysis. The relevant electronic databases were searched. All of the raw data of the eligible citations were extracted. The frequency estimates were stratified by geography, ethnicity and sex. Results Sixty-six studies were identified with a total of 92277 study participants. The meta-analysis revealed that the frequencies of the MTHFR C677T, A1298C, and MTRR A66G gene polymorphisms varied significantly between different ethnic groups and along geographical gradients. The frequencies of the 677T allele and 677TT genotype increased along the southern-central-northern direction across Mainland China (all Pvalues≤0.001). The frequencies of the 1298C, 1298CC, 66G and 66GG genotypes decreased along the south-central-north direction across the country (all Pvalues≤0.001). Conclusions Our meta-analysis strongly indicates significant geographical and ethnic variations in the frequencies of the C677T, A1298C, and A66G gene polymorphisms in the folate metabolism pathway among Chinese populations. PMID:27089387

  20. Variants in maternal COMT and MTHFR genes and risk of neural tube defects in offspring.

    PubMed

    Liu, Jufen; Zhang, Yali; Jin, Lei; Li, Guoxing; Wang, Linlin; Bao, Yanping; Fu, Yunting; Li, Zhiwen; Zhang, Le; Ye, Rongwei; Ren, Aiguo

    2015-04-01

    Methylenetetrahydrofolate reductase (MTHFR) C677T and catechol-O-Methyltransferase (COMT) G158A are associated with a risk of neural tube defects (NTDs) in offspring. This study examined the effect of a MTHFR × COMT interaction on the risk of NTDs in a Chinese population with a high prevalence of NTDs. A total of 576 fetuses or newborns with NTDs and 594 controls were genotyped for MTHFRrs1801133, MTHFRrs1801131, and COMTrs4680 and COMTrs737865. Information on maternal sociodemographic characteristics, reproductive history, and related behavior was collected through face-to-face interviews. Possible interactions between genetic variants of MTHFR and COMT were examined. MTHFR C677T homozygous TT was associated with an elevated risk of total NTDs (odds ratio [OR] = 1.37, 95 % confidence interval [CI] = 0.93-2.03) and of anencephaly (OR = 1.67, 95 % CI = 0.98-2.84) compared with the CC genotype. There was a COMT rs737865 CC × MTHFR rs1801133 TT interaction for total NTDs (OR = 3.02, 95 % CI = 1.00-9.14) and for anencephaly (OR = 3.39, 95 % CI = 0.94-12.18). No interaction was found between COMT rs4680 AA/AG and MTHFR CT/TT genotypes for total NTDs or any subtype of NTD. The interaction of COMT rs737865 and MTHFR C677T was associated with an increased risk of NTDs, especially anencephaly, in a Chinese population with a high prevalence of NTDs. PMID:24990354

  1. MTHFR genetic polymorphism as a risk factor in Egyptian mothers with Down syndrome children.

    PubMed

    Meguid, Nagwa A; Dardir, Ahmed A; Khass, Mohamed; Hossieny, Lamia El; Ezzat, Afaf; El Awady, Mostafa K

    2008-01-01

    Recent reports linking Down syndrome (DS) to maternal polymorphisms at the methylenetetrahydrofolate reductase (MTHFR) gene locus have generated great interest among investigators in the field. The present study aimed at evaluation of MTHFR 677C/T and 1298A/C polymorphisms in the MTHFR gene as maternal risk factors for DS. Forty two mothers of proven DS outcomes and forty eight control mothers with normal offspring were included. Complete medical and nutritional histories for all mothers were taken with special emphasis on folate intake. Folic acid intake from food or vitamin supplements was significantly low (below the Recommended Daily Allowance) in the group of case mothers compared to control mothers. Frequencies of MTHFR 677T and MTHFR 1298C alleles were significantly higher among case mothers (32.1% and 57.1%, respectively) compared to control mothers (18.7% and 32.3%, respectively). Heterozygous and homozygous genotype frequencies of MTHFR at position 677 (CT and TT) were higher among case mothers than controls (40.5% versus 25% and 11.9% versus 6.2%, respectively) with an odds ratio of 2.34 (95% confidence interval [CI] 0.93-5.89) and 2.75 (95% CI 0.95-12.77), respectively. Interestingly, the homozygous genotype frequency (CC) at position 1298 was significantly higher in case mothers than in controls (33.3% versus 2.1% respectively) with an odds ratio of 31.5 (95% CI 3.51 to 282.33) indicating that this polymorphism may have more genetic impact than 677 polymorphism. Heterozygous genotype (AC) did not show significant difference between the two groups. We here report on the first pilot study of the possible genetic association between DS and MTHFR 1298A/C genotypes among Egyptians. Further extended studies are recommended to confirm the present work. PMID:18057532

  2. Association of the MTHFR rs1801131 and rs1801133 variants in sporadic Parkinson's disease patients.

    PubMed

    Yuan, Lamei; Song, Zhi; Deng, Xiong; Xiong, Wei; Yang, Zhijian; Deng, Hao

    2016-03-11

    Parkinson's disease (PD) is a common age-dependent neurodegenerative movement disorder related to multiple factors, and genetic factors play an important role in the pathogenesis of PD. Variants in the methylenetetrahydrofolate reductase gene (MTHFR), a gene encoding a folate-dependent enzyme that is involved in homocysteine metabolism, have been reported to be associated with PD. To explore the role of the MTHFR gene in the development of PD in Chinese Han population, we analyzed two MTHFR variants (rs1801131 and rs1801133) in a patient cohort consisting of 512 patients with PD from mainland China and a control cohort consisting of 512 age, gender and ethnicity matched normal subjects. Statistically significant differences in genotypic and allelic frequencies were detected in the MTHFR variant rs1801133 (P=0.022 and 0.007, respectively; odds ratio=0.780, 95% confidence interval=0.651-0.934). In addition, the A-T haplotype of rs1801131-rs1801133 showed a protective role against PD development (P=0.007, odds ratio=0.779, 95% confidence interval=0.650-0.933). Our results suggested that the T allele of rs1801133 variant and A-T haplotype of rs1801131-rs1801133 in the MTHFR gene may decrease the risk of developing PD in Chinese Han population from mainland China. PMID:26806866

  3. C677T (RS1801133 ) MTHFR gene polymorphism frequency in a colombian population

    PubMed Central

    Gómez-Gutierrez, Alberto; Gómez, Piedad Elena; Casas-Gomez, Maria Consuelo; Briceño, Ignacio

    2015-01-01

    Introduction: Abnormal levels of the enzyme methylenetetrahydrofolate reductase (MTHFR) are associated with an increased risk of both cardiovascular and cerebrovascular disease and higher concentrations of homocysteine. Abnormal levels are also related to birth defects, pregnancy complications, cancer and toxicity to methotrexate (MTX). Polymorphisms of MTHFR affect the activity of the enzyme. Genetic associations have been related to treatment efficacy. Objective: To establish the frequency of the C> T polymorphism at nucleotide 677 of the MTHFR gene in a group of Colombian individuals. Methods: Data from pharmacogenetic microarrays that include MTX sensibility-associated polymorphisms were retrospectively collected (Pathway Genomics®). The frequency of the C> T MTHFR rs1801133 marker polymorphism was analyzed. Results: Microarray data from 68 men and 84 women were analyzed. Comparisons of genotype C/C vs. C/T and T/T were statistically significantly different (p= 0.00, p= 0.026, respectively), as were C/T and T / T (p= 0.0001). Conclusions: Results for the C/C and C/T genotypes in a Colombian population are similar to other previously studied groups of healthy subjects. Subjects from our population might be at risk of developing diseases associated with MTHFR polymorphisms and might present toxicity and adverse effects if treated with MTX, which suggests the need to evaluate therapeutic alternatives based on individual pharmacogenetic studies. PMID:26309343

  4. Prevalence of MTHFR C677T Polymorphism in North Indian Mothers Having Babies with Trisomy 21 Down Syndrome

    ERIC Educational Resources Information Center

    Kohli, Utkarsh; Arora, Sadhna; Kabra, Madhulika; Ramakrishnan, Lakshmy; Gulati, Sheffali; Pandey, Ravindra

    2008-01-01

    Recent studies have evaluated possible links between polymorphisms in maternal folate metabolism genes and Down syndrome. Some of these studies show a significantly increased prevalence of the C677T polymorphism of the 5,10-methylene tetrahydrofolate reductase (NADPH) gene (MTHFR) among mothers who have had babies with Down syndrome. This study…

  5. Association of Polymorphisms in BDNF, MTHFR, and Genes Involved in the Dopaminergic Pathway with Memory in a Healthy Chinese Population

    ERIC Educational Resources Information Center

    Yeh, Ting-Kuang; Hu, Chung-Yi; Yeh, Ting-Chi; Lin, Pei-Jung; Wu, Chung-Hsin; Lee, Po-Lei; Chang, Chun-Yen

    2012-01-01

    The contribution of genetic factors to the memory is widely acknowledged. Research suggests that these factors include genes involved in the dopaminergic pathway, as well as the genes for brain-derived neurotrophic factor (BDNF) and methylenetetrahydrofolate reductase (MTHFR). The activity of the products of these genes is affected by single…

  6. Methylenetetrahydrofolate reductase homozygosis and low-density lipoproteins in patients with genotype 1 chronic hepatitis C.

    PubMed

    Petta, S; Bellia, C; Mazzola, A; Cabibi, D; Cammà, C; Caruso, A; Di Marco, V; Craxì, A; Ciaccio, M

    2012-07-01

    Methylenetetrahydrofolate reductase status, homocysteine and lipoproteins levels have been associated with severity of disease and both rapid and sustained virological response (SVR) in patients with genotype 1 chronic hepatitis C (CHC). We aimed to assess the association of homocysteine and MTHFR status with serum cholesterol levels and their potential links to both histological findings and virological response, in patients with genotype 1 hepatitis C virus (HCV). A total of 119 consecutive patients were evaluated by biopsy and metabolic measurements. A total of 103 healthy blood donors were used as controls. Serum homocysteine and MTHFR C677T mutation were also evaluated. All patients underwent antiviral therapy with PEG-IFN alfa-2a plus ribavirin. HCV-RNA was assessed at baseline, week 4, week 12, at the end of therapy and after 6 months of follow-up. Mean serum values of homocysteine were higher in patients than in controls (15.8 ± 5.8 μg/L vs 12.5 ± 5.8 μg/L; P < 0.001), with a similar CC, CT and TT MTHFR distribution (23.6%, 48.7% and 27.7% in G1-CHC vs 34%, 48.5% and 17.5% in controls; P = 0.14). In genotype 1, HCV MTHFR TT homozygosis was independently linked to higher LDL (OR 1.016; CI 1.002-1.031; P = 0.03), but not to homocysteine. No association were found between homocysteine, MTHFR and histological features or both rapid virological response (RVR) and SVR. Low cholesterol (OR 0.988, 95%CI 0.975-0.999, P = 0.04) was independently linked to severe fibrosis, and high LDL was the only independent positive predictors of both RVR and SVR (OR 1.036; 95%CI 1.017-1.055; P < 0.001; and OR 1.016; 95%CI 1.001-1.031; P = 0.04 respectively). In patients with genotype 1 hepatitis C, showing higher homocysteine serum levels than controls, MTHFR C677T homozygosis, via modulating cholesterol levels, could interfere with liver fibrosis and response to antiviral therapy. PMID:22676358

  7. 5,10-methylene tetrahydrofolate reductase C677T gene polymorphism, homocysteine concentration and the extent of premature coronary artery disease in southern Iran.

    PubMed

    Senemar, Sara; Saffari, Babak; Sharifkazemi, Mohammad Bagher; Bahari, Marzieh; Jooyan, Najmeh; Dehaghani, Elham Davoudi; Yavarian, Majid

    2013-01-01

    Elevated level of plasma homocysteine (Hcy) has been identified as an independent risk factor for coronary artery disease (CAD). Furthermore, numerous studies have documented the influences of a common polymorphism (C677T) of methylenetetrahydrofolate reductase (MTHFR) on homocysteine levels. However the relationship between this mutation and cardiovascular diseases (CVD) has remained as a controversial issue. The present study was undertaken to investigate the relationship between C677T polymorphism of MTHFR gene, plasma total Hcy levels and the number of affected vessels as a criterion for the extent of CAD. MTHFR genotypes and plasma homocysteine (HCY) concentrations were examined in 231 patients and 300 healthy subjects who underwent diagnostic coronary angiography. A multiple linear regression analysis was performed to identify the predictors of Hcy levels whereas logistic regression model was built to determine the association of Hcy quartiles with the risk of CAD adjusted for risk factors. The prevalence of MTHFR genotypes was similar between CAD patients and non-CAD individuals while the geometric mean of Hcy values was significantly higher in patient group (14.13 ± 4.11 μmol/l) than in control group (10.19 ± 3.52 μmol/l) (P < 0.001). Moreover, unlike the MTHFR polymorphism, Hcy concentration increased with increasing number of stenosed vessels and the CAD risk increased about 2 folds in the top two Hcy quartiles (≥ 17.03 and 13.20-17.02 μmol/l) compared with the lowest quartile (≤ 9.92 μmol/l) after controlling for conventional risk factors (P<0.001 for both). Our data suggest that hyperhomocysteinaemia (HHcy) is significantly associated to CAD risk increase as well as to the extent of coronary atherosclerosis. PMID:26417236

  8. Pneumocystis jirovecii infection and the associated dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR) mutations in HIV-positive individuals from Pune, India.

    PubMed

    Mane, Arati; Gujar, Pankaj; Chandra, Jipsi; Lokhande, Rahul; Dhamgaye, Tilak; Ghorpade, Shivhari; Risbud, Arun

    2015-02-01

    The present study was undertaken to detect Pneumocystis jirovecii infection among HIV-positive patients presenting with symptoms of lower respiratory tract infection and analyze the associated dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR) mutations. P. jirovecii infection was detected in 12.6% cases. We did not find DHPS gene mutations at the commonest positions of codon 55 and 57; however, mutation at codon 171 was detected in two cases. No mutations in DHFR gene were detected. The results indicate low prevalence of DHPS and DHFR mutations in Indian P. jirovecii isolates, suggesting that the selective pressure of sulfa drugs on the local strains has probably not reached the levels found in developed nations. PMID:25266324

  9. Targeted Mutations of Bacillus anthracis Dihydrofolate Reductase Condense Complex Structure-Activity Relationships

    SciTech Connect

    J Beierlein; N Karri; A Anderson

    2011-12-31

    Several antifolates, including trimethoprim (TMP) and a series of propargyl-linked analogues, bind dihydrofolate reductase from Bacillus anthracis (BaDHFR) with lower affinity than is typical in other bacterial species. To guide lead optimization for BaDHFR, we explored a new approach to determine structure-activity relationships whereby the enzyme is altered and the analogues remain constant, essentially reversing the standard experimental design. Active site mutants of the enzyme, Ba(F96I)DHFR and Ba(Y102F)DHFR, were created and evaluated with enzyme inhibition assays and crystal structures. The affinities of the antifolates increase up to 60-fold with the Y102F mutant, suggesting that interactions with Tyr 102 are critical for affinity. Crystal structures of the enzymes bound to TMP and propargyl-linked inhibitors reveal the basis of TMP resistance and illuminate the influence of Tyr 102 on the lipophilic linker between the pyrimidine and aryl rings. Two new inhibitors test and validate these conclusions and show the value of the technique for providing new directions during lead optimization.

  10. Prospective evaluation of the thrombotic risk in children with acute lymphoblastic leukemia carrying the MTHFR TT 677 genotype, the prothrombin G20210A variant, and further prothrombotic risk factors.

    PubMed

    Nowak-Göttl, U; Wermes, C; Junker, R; Koch, H G; Schobess, R; Fleischhack, G; Schwabe, D; Ehrenforth, S

    1999-03-01

    The reported incidence of thromboembolism in children with acute lymphoblastic leukemia (ALL) treated with L-asparaginase, vincristine, and prednisone varies from 2.4% to 11.5%. The present study was designed to prospectively evaluate the role of the TT677 methylenetetrahydrofolate reductase (MTHFR) genotype, the prothrombin G20210A mutation, the factor V G1691A mutation, deficiencies of protein C, protein S, antithrombin, and increased lipoprotein (a) concentrations in leukemic children treated according to the ALL-Berlin-Frankfurt-Muenster (BFM) 90/95 study protocols with respect to the onset of vascular events. Three hundred and one consecutive leukemic children were enrolled in this study. Fifty-five of these 301 subjects investigated had one established single prothrombotic risk factor: 20 children showed the TT677 MTHFR genotype; 5 showed the heterozygous prothrombin G20210A variant; 11 were carriers of the factor V G1691A mutation (heterozygous, n = 10; homozygous, n = 1); 4 showed familial protein C, 4 protein S, and 2 antithrombin type I deficiency; 9 patients were suffering from familially increased lipoprotein (a) [Lp(a)] concentrations (>30 mg/dL). In addition, combined prothrombotic defects were found in a further 10 patients: the FV mutation was combined with the prothrombin G20210A variant (n = 1), increased Lp(a) (n = 3), protein C deficiency (n = 1), and homozygosity for the C677T MTHFR gene mutation (n = 1). Lp(a) was combined with protein C deficiency (n = 2) and the MTHFR TT 677 genotype (n = 2). Two hundred eighty-nine of the 301 patients were available for thrombosis-free survival analysis. In 32 (11%) of these 289 patients venous thromboembolism occurred. The overall thrombosis-free survival in patients with at least one prothrombotic defect was significantly reduced compared with patients without a prothrombotic defect within the hemostatic system (P <.0001). In addition, a clear-cut positive correlation (P <.0001) was found between

  11. Lack of association between MTHFR C677T polymorphism and breast cancer risk in Ahvaz, west south-Iran

    PubMed Central

    Mohammadzadeh, Ghorban; Karimi, Maryam; Bazyar, Mohammad; Hosseini, Seyed-Mohammad

    2016-01-01

    Background: Association between C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR), a key enzyme involved in folate metabolism and DNA methylation, and breast cancer risk are inconsistent. We investigated in a case-control study, possible effect of the common MTHFR C677T polymorphism on breast cancer risk in a sample of Iranian patients. Materials and Methods: The study subjects comprised of 123 breast cancer cases and 110 cancer-free control, who were matched for age and body mass index (BMI). C677T genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Lipid profile was measured in all subjects by standard method. Results: The genotypes distributions (CC, CT, and TT) were 55.3, 39, and 5.7% in breast cancer cases and 51.8, 44.5, and 3.6% in controls. Chi square analysis revealed that there was no significant association between breast cancer risk and MTHFR genotypes and alleles. Additionally, no significant association was observed between C677T genotypes and biochemistry parameters. A multinomial logistic regression model with MTHFR genotypes, lipid profiles, BMI and age as covariates revealed that there is no significant association between MTHFR genotypes and risk of breast cancer, but higher values of LDL and HDL significantly increase risk of breast cancer. Conclusions: Our findings do not support the hypothesis that genetic variation in the MTHFR C677T polymorphism is implicated in the breast cancer risk in a sample of Iranian patients. PMID:27014653

  12. MTHFR genotype and colorectal adenoma recurrence: data from a double-blind placebo-controlled clinical trial.

    PubMed

    Levine, A Joan; Wallace, Kristin; Tsang, Shirley; Haile, Robert W; Saibil, Fred; Ahnen, Dennis; Cole, Bernard F; Barry, Elizabeth L; Munroe, David J; Ali, Iqbal U; Ueland, Per; Baron, John A

    2008-09-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. We assessed the association between two common MTHFR variants, 677C>T and 1298A>C, and adenoma recurrence in the context of a randomized double- blind clinical trial of aspirin use and folate supplementation. We used generalized linear regression to estimate risk ratios and 95% confidence intervals (95% CI) for recurrence, adjusting for age, sex, clinical center, follow-up time, and treatment status. Neither MTHFR polymorphism was associated with overall or advanced adenoma recurrence. Compared with those with two wild-type alleles, the relative risk for advanced adenoma was 0.75 (95% CI, 0.36-1.55) for the MTHFR 677 TT genotype and 1.16 (95% CI, 0.58-2.33) for the MTHFR 1298 CC genotype. The effect of folate supplementation on recurrence risk did not differ by genotype. Our findings indicate that the MTHFR genotype does not change adenoma risk in a manner similar to its effect on colorectal cancer, and does not modify the effect of folate supplementation on metachronous adenoma risk. PMID:18768511

  13. Asymmetric mutations in the tetrameric R67 dihydrofolate reductase reveal high tolerance to active-site substitutions

    PubMed Central

    Ebert, Maximilian C C J C; Morley, Krista L; Volpato, Jordan P; Schmitzer, Andreea R; Pelletier, Joelle N

    2015-01-01

    Type II R67 dihydrofolate reductase (DHFR) is a bacterial plasmid-encoded enzyme that is intrinsically resistant to the widely-administered antibiotic trimethoprim. R67 DHFR is genetically and structurally unrelated to E. coli chromosomal DHFR and has an unusual architecture, in that four identical protomers form a single symmetrical active site tunnel that allows only one substrate binding/catalytic event at any given time. As a result, substitution of an active-site residue has as many as four distinct consequences on catalysis, constituting an atypical model of enzyme evolution. Although we previously demonstrated that no single residue of the native active site is indispensable for function, library selection here revealed a strong bias toward maintenance of two native protomers per mutated tetramer. A variety of such “half-native” tetramers were shown to procure native-like catalytic activity, with similar KM values but kcat values 5- to 33-fold lower, illustrating a high tolerance for active-site substitutions. The selected variants showed a reduced thermal stability (Tm ∼12°C lower), which appears to result from looser association of the protomers, but generally showed a marked increase in resilience to heat denaturation, recovering activity to a significantly greater extent than the variant with no active-site substitutions. Our results suggest that the presence of two native protomers in the R67 DHFR tetramer is sufficient to provide native-like catalytic rate and thus ensure cellular proliferation. PMID:25401264

  14. A New Strategy to Produce a Defensin: Stable Production of Mutated NP-1 in Nitrate Reductase-Deficient Chlorella ellipsoidea

    PubMed Central

    Chen, Yu-Hong; Niu, Li-Li; Sun, Yong-Ru; Zhao, Shi-Min; Yang, Fu-Quan; Wang, Richard R.-C.; Wu, Qing; Zhang, Xiang-Qi; Hu, Zan-Min

    2013-01-01

    Defensins are small cationic peptides that could be used as the potential substitute for antibiotics. However, there is no efficient method for producing defensins. In this study, we developed a new strategy to produce defensin in nitrate reductase (NR)-deficient C. ellipsoidea (nrm-4). We constructed a plant expression vector carrying mutated NP-1 gene (mNP-1), a mature α-defensin NP-1 gene from rabbit with an additional initiator codon in the 5′-terminus, in which the selection markers were NptII and NR genes. We transferred mNP-1 into nrm-4 using electroporation and obtained many transgenic lines with high efficiency under selection chemicals G418 and NaNO3. The mNP-1 was characterized using N-terminal sequencing after being isolated from transgenic lines. Excitingly, mNP-1 was produced at high levels (approximately 11.42 mg/l) even after 15 generations of continuous fermentation. In addition, mNP-1 had strong activity against Escherichia coli at 5 µg/ml. This research developed a new method for producing defensins using genetic engineering. PMID:23383016

  15. Gender-Specific Effect of Mthfr Genotype and Neonatal Vigabatrin Interaction on Synaptic Proteins in Mouse Cortex

    PubMed Central

    Blumkin, Elinor; Levav-Rabkin, Tamar; Melamed, Osnat; Galron, Dalia; Golan, Hava M

    2011-01-01

    The enzyme methylenetetrahydrofolate reductase (MTHFR) is a part of the homocysteine and folate metabolic pathways, affecting the methylations of DNA, RNA, and proteins. Mthfr deficiency was reported as a risk factor for neurodevelopmental disorders such as autism spectrum disorder and schizophrenia. Neonatal disruption of the GABAergic system is also associated with behavioral outcomes. The interaction between the epigenetic influence of Mthfr deficiency and neonatal exposure to the GABA potentiating drug vigabatrin (GVG) in mice has been shown to have gender-dependent effects on mice anxiety and to have memory impairment effects in a gender-independent manner. Here we show that Mthfr deficiency interacts with neonatal GABA potentiation to alter social behavior in female, but not male, mice. This impairment was associated with a gender-dependent enhancement of proteins implicated in excitatory synapse plasticity in the female cortex. Reelin and fragile X mental retardation 1 protein (FMRP) levels and membrane GluR1/GluR2 ratios were elevated in wild-type mice treated neonatally with GVG and in Mthfr+/− mice treated with saline, but not in Mthfr+/− mice treated with GVG, compared with control groups (wild type treated with saline). A minor influence on the levels of these proteins was observed in male mice cortices, possibly due to high basal protein levels. Interaction between gender, genotype, and treatment was also observed in the GABA pathway. In female mice, GABA Aα2/gephyrin ratios were suppressed in all test groups; in male mice, a genotype-specific enhancement of GABA Aα2/gephyrin was observed. The lack of an effect on either reln or Fmr1 transcription suggests post-transcriptional regulation of these genes. Taken together, these findings suggest that Mthfr deficiency may interact with neonatal GABA potentiation in a gender-dependent manner to interrupt synaptic function. This may illustrate a possible mechanism for the epigenetic involvement of Mthfr

  16. Association of C677T MTHFR and G20210A FII prothrombin polymorphisms with susceptibility to myocardial infarction

    PubMed Central

    Hmimech, Wiam; Idrissi, Hind Hassani; Diakite, Brehima; Baghdadi, Dalila; Korchi, Farah; Habbal, Rachida; Nadifi, Sellama

    2016-01-01

    Myocardial infarction (MI) is a common complex pathology, localized in the main leading causes of mortality worldwide. It is the result of the interaction of genetic and environmental factors. The aim of the present study was to investigate the potential association of C677T 5,10-methylenetetrahydrofolate reductase (MTHFR) (rs1801133) and G20210A factor II prothrombin (FII) (rs1799963) polymorphisms with the susceptibility of MI. Following extraction by the standard salting-out procedure, DNA samples of 100 MI patients and 182 apparently healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism using HinfI and HindIII restriction enzymes, respectively. The results show a significant association of the G20210T FII polymorphism with the MI risk. The frequencies of the heterozygote genotype GA, homozygous mutated AA and the G20210A allele was higher among patients compared to controls (GA: 59 vs. 5.5%, P<0.001; AA: 10 vs. 0%, P=0.003; and 20210A: 39.5 vs. 2.7%, P<0.003), suggesting that this polymorphism may be a potential genetic marker for MI. No significant association was observed between the C677T MTHFR and MI occurrence, and there was more heterozygote CT in the patient group compared to the controls. As a multifactorial disease, the development of MI may be the result of numerous factors that influence synergistically its occurrence. Thus, further studies are merited to try to better assess these associations (gene-gene and gene-environment interactions). PMID:27588178

  17. Methylenetetrahydrofolate reductase, diet, and risk of colon cancer.

    PubMed

    Slattery, M L; Potter, J D; Samowitz, W; Schaffer, D; Leppert, M

    1999-06-01

    Individuals with different forms of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, carriers of the C677T mutation versus wild type, show differences in enzyme levels; these differences have been hypothesized to be related to DNA methylation and, perhaps, to the nucleotide pool size. Using data from an incident case-control study, we evaluated the combined effect of dietary intake of folate, methionine, vitamin B6, vitamin B12, and alcohol and various forms of the MTHFR gene on risk of colon cancer. Individuals homozygous for the variant form of the MTHFR gene (TT) had a slightly lower risk of colon cancer than did individuals who were wild type [CC, odds ratio (OR) = 0.8, 95% confidence interval (CI) = 0.6-1.1 for men; and OR = 0.9, 95% CI = 0.6-1.2 for women]. High levels of intake of folate, vitamin B6, and vitamin B12 were associated with a 30-40% reduction in risk of colon cancer among those with the TT relative to those with low levels of intake who were CC genotype. Associations were stronger for proximal tumors, in which high levels of intake of these nutrients were associated with a halving of risk among those with the TT genotype. The inverse association with high levels of these nutrients in those with the TT genotype was stronger among those diagnosed at an older age. Although imprecise, the inverse association with the low-risk diet that was high in folate and methionine and without alcohol was observed for both the TT genotype (OR = 0.4 95% CI = 0.1-0.9) and the CC/CT genotype (OR = 0.6, 95% CI = 0.4-1.0), but this association was not seen with the high-risk diet for either the TT or CC/CT genotype. Although associations were generally weak, these findings suggest that those with differing MTHFR genotypes may have different susceptibilities to colon cancer, based on dietary consumption of folate, vitamin B6, and vitamin B12. PMID:10385141

  18. Interaction between the MTHFR C677T polymorphism and traumatic childhood events predicts depression.

    PubMed

    Lok, A; Bockting, C L H; Koeter, M W J; Snieder, H; Assies, J; Mocking, R J T; Vinkers, C H; Kahn, R S; Boks, M P; Schene, A H

    2013-01-01

    Childhood trauma is associated with the onset and recurrence of major depressive disorder (MDD). The thermolabile T variant of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) is associated with a limited (oxidative) stress defense. Therefore, C677T MTHFR could be a potential predictor for depressive symptomatology and MDD recurrence in the context of traumatic stress during early life. We investigated the interaction between the C677T MTHFR variant and exposure to traumatic childhood events (TCEs) on MDD recurrence during a 5.5-year follow-up in a discovery sample of 124 patients with recurrent MDD and, in an independent replication sample, on depressive symptomatology in 665 healthy individuals from the general population. In the discovery sample, Cox regression analysis revealed a significant interaction between MTHFR genotype and TCEs on MDD recurrence (P=0.017). Over the 5.5-year follow-up period, median time to recurrence was 191 days for T-allele carrying patients who experienced TCEs (T+ and TCE+); 461 days for T- and TCE+ patients; 773 days for T+ and TCE- patients and 866 days for T- and TCE- patients. In the replication sample, a significant interaction was present between the MTHFR genotype and TCEs on depressive symptomatology (P=0.002). Our results show that the effects of TCEs on the prospectively assessed recurrence of MDD and self-reported depressive symptoms in the general population depend on the MTHFR genotype. In conclusion, T-allele carriers may be at an increased risk for depressive symptoms or MDD recurrence after exposure to childhood trauma. PMID:23900311

  19. MTHFR polymorphisms and Opisthorchis viverrini infection: a relationship with increased susceptibility to cholangiocarcinoma in Thailand.

    PubMed

    Songserm, Nopparat; Promthet, Supannee; Sithithaworn, Paiboon; Pientong, Chamsai; Ekalaksananan, Tipaya; Chopjitt, Peechanika; Parkin, Donald Maxwell

    2011-01-01

    Opisthorchis viverrini (OV) infection is the major risk factor for cholangiocarcinoma (CCA). Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme in folate metabolism. Change in MTHFR activity may influence both DNA methylation and synthesis, crucial steps in carcinogenesis. This study aimed to investigate the association between MTHFR polymorphisms and OV infection with CCA risk in a high-incidence area of Thailand. A nested case-control study within cohort study was carried out: 219 subjects with primary CCA were matched with two non-cancer controls from the same cohort on sex, age at recruitment and presence/ absence of OV eggs in stool. At the time of recruitment information on consumption of foodstuffs potentially contaminated by OV was obtained by questionnaire. MTHFR polymorphisms were analyzed using PCR with high resolution melting analysis. Associations between variables and the risk of CCA were assessed using conditional logistic regression. Risk of CCA was related to consumption of a dish of raw freshwater fish (Koi- Pla) with clear dose-response effects, and there were joint effects on CCA risk between MTHFR polymorphisms and consumption of dishes containing raw- and/or semi-raw freshwater fish. This study provides evidence to support a relationship of increased susceptibility to CCA in individuals with MTHFR variants, especially for those individuals who have OV infection or consume semi-raw freshwater fish (acting either as a source of OV or of pre-formed nitrosamine). Folate may play an important role in OV-related cholangiocarcinogenesis by upsetting the balance between DNA methylation and synthesis in the folate pathway. PMID:21875294

  20. Methionine synthase reductase 66A->G polymorphism is associated with increased plasma homocysteine concentration when combined with the homozygous methylenetetrahydrofolate reductase 677C->T variant.

    PubMed

    Vaughn, Jaimie D; Bailey, Lynn B; Shelnutt, Karla P; Dunwoody, Kristina M von-Castel; Maneval, David R; Davis, Steven R; Quinlivan, Eoin P; Gregory, Jesse F; Theriaque, Douglas W; Kauwell, Gail P A

    2004-11-01

    Methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) are important for homocysteine remethylation. This study was designed to determine the influence of genetic variants (MTHFR 677C-->T, MTHFR 1298A-->C, and MTRR 66A-->G), folate, and vitamin B-12 status on plasma homocysteine in women (20-30 y; n = 362). Plasma homocysteine was inversely (P < 0.0001) associated with serum folate and plasma vitamin B-12 regardless of genotype. Plasma homocysteine was higher (P < 0.05) for women with the MTHFR 677 TT/1298 AA genotype combination compared with the CC/AA, CC/AC, and CT/AA genotypes. Women with the MTHFR 677 TT/MTRR 66 AG genotype had higher (P < 0.05) plasma homocysteine than all other genotype combinations except the TT/AA and TT/GG genotypes. There were 5.4-, 4.3-, and 3.8-fold increases (P < 0.001) in risk for plasma homocysteine in the top 5, 10, and 20%, respectively, of the homocysteine distribution for subjects with the MTHFR 677 TT compared with the CC and CT genotypes. Predicted plasma homocysteine was inversely associated with serum folate (P = 0.003) and plasma vitamin B-12 (P = 0.002), with the degree of correlation dependent on MTHFR 677C-->T genotype. These data suggest that coexistence of the MTHFR 677 TT genotype with the MTRR 66A-->G polymorphism may exacerbate the effect of the MTHFR variant alone. The potential negative effect of combined polymorphisms of the MTHFR and MTRR genes on plasma homocysteine in at-risk population groups with low folate and/or vitamin B-12 status, such as women of reproductive potential, deserves further investigation. PMID:15514263

  1. Polymorphism in methylenetetrahydrofolate reductase, plasminogen activator inhibitor-1, and apolipoprotein E in hemodialysis patients.

    PubMed

    Al-Muhanna, Fahad; Al-Mueilo, Samir; Al-Ali, Amein; Larbi, Emmanuel; Rubaish, Abdullah; Abdulmohsen, Mohammed Fakhry; Al-Zahrani, Alhussain; Al-Ateeq, Suad

    2008-11-01

    The methylenetetrahydrofolate reductase (MTHFR) gene polymorphism, apolipoprotein E (apo epsilon4) gene polymorphism and polymorphism of plasminogen activator inhibitor-1 (PAI-1) have been shown to be associated with end-stage renal disease (ESRD). To determine the prevalence of these mutations in Saudi patients with ESRD on hemodialysis, we studied the allelic frequency and genotype distribution in patients receiving hemodialysis and in a control group, all residing in the Eastern Province of Saudi Arabia. The genotypes were determined using allele specific hybridization procedures and were confirmed by restriction fragment length polymorphism. The T allele frequency and homozygous genotype of MTHFR in ESRD patients were 14% and 2.4%, respectively compared to 13.4% and 0%, respectively in the control group. The allele frequency and homozygous genotype of 4G/4G PAI-1 gene polymorphism were 46.4% and 4.8% respectively in ESRD patients compared to 57.1% and 32% respectively in the control group. The apo s4 allele frequency and homozygous genotype distribution in hemodialysis patients were 7% and 2.4%, respectively compared to 13% and 2% in the control group. Although allele frequency of C677T of MTHFR was statistically similar in the hemodialysis patients and in the control group, the homozygotes T allele genotype was over represented in the hemodialysis group compared to normal. The prevalence of PAI-1 4G/4G polymorphism in ESRD patients was lower when compared to the control group. The prevalence of apo s4 allele did not differ significantly between the two groups. The present results demonstrate that all three studied polymorphic mutations are present in our population and that they may contribute to the etiology of the disease in our area. PMID:18974580

  2. High folic acid consumption leads to pseudo-MTHFR deficiency, altered lipid metabolism, and liver injury in mice12345

    PubMed Central

    Christensen, Karen E; Mikael, Leonie G; Leung, Kit-Yi; Lévesque, Nancy; Deng, Liyuan; Wu, Qing; Malysheva, Olga V; Best, Ana; Caudill, Marie A; Greene, Nicholas DE

    2015-01-01

    Background: Increased consumption of folic acid is prevalent, leading to concerns about negative consequences. The effects of folic acid on the liver, the primary organ for folate metabolism, are largely unknown. Methylenetetrahydrofolate reductase (MTHFR) provides methyl donors for S-adenosylmethionine (SAM) synthesis and methylation reactions. Objective: Our goal was to investigate the impact of high folic acid intake on liver disease and methyl metabolism. Design: Folic acid–supplemented diet (FASD, 10-fold higher than recommended) and control diet were fed to male Mthfr+/+ and Mthfr+/− mice for 6 mo to assess gene-nutrient interactions. Liver pathology, folate and choline metabolites, and gene expression in folate and lipid pathways were examined. Results: Liver and spleen weights were higher and hematologic profiles were altered in FASD-fed mice. Liver histology revealed unusually large, degenerating cells in FASD Mthfr+/− mice, consistent with nonalcoholic fatty liver disease. High folic acid inhibited MTHFR activity in vitro, and MTHFR protein was reduced in FASD-fed mice. 5-Methyltetrahydrofolate, SAM, and SAM/S-adenosylhomocysteine ratios were lower in FASD and Mthfr+/− livers. Choline metabolites, including phosphatidylcholine, were reduced due to genotype and/or diet in an attempt to restore methylation capacity through choline/betaine-dependent SAM synthesis. Expression changes in genes of one-carbon and lipid metabolism were particularly significant in FASD Mthfr+/− mice. The latter changes, which included higher nuclear sterol regulatory element-binding protein 1, higher Srepb2 messenger RNA (mRNA), lower farnesoid X receptor (Nr1h4) mRNA, and lower Cyp7a1 mRNA, would lead to greater lipogenesis and reduced cholesterol catabolism into bile. Conclusions: We suggest that high folic acid consumption reduces MTHFR protein and activity levels, creating a pseudo-MTHFR deficiency. This deficiency results in hepatocyte degeneration, suggesting a 2

  3. MTHFR genetic polymorphism increases the risk of preterm delivery

    PubMed Central

    Nan, Yanrong; Li, Hongmei

    2015-01-01

    Aims: This study aimed to investigate the association between the methylene tetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms and premature delivery susceptibility. Methods: With matched age and gender, 108 premature delivery pregnant women as cases and 108 healthy pregnant women as controls were recruited in this case-control study. The cases and controls had same gestational weeks. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was adopted to analyze C677T and A1298C polymorphisms of the participants. Linkage disequilibrium (LD) and haplotype analysis were conducted by Haploview software. The differences for frequencies of gene type, allele and haplotypes in cases and controls were tested by chi-square test. The relevant risk of premature delivery was represented by odds ratios (ORs) with 95% confidence intervals (95% CIs). Results: TT gene type frequency of C677T polymorphsim was higher in cases than the controls (P=0.004, OR=3.077, 95% CI=1.469-6.447), so was allele T (P=0.002, OR=1.853, 95% CI=1.265-2.716). Whereas, CC gene type of A1298C polymorphism had a lower distribution in cases than the controls (P=0.008, OR=0.095, 95% CI=0.012-0.775), so was allele C (P=0.047, OR=0.610, 95% CI=0.384-0.970). Haplotype analysis and linkage disequilibrium test conducted on the alleles of two polymorphisms in MTHFR gene, we discovered that haplotype T-A had a higher distribution in cases, which indicated that susceptible haplotype T-A was the candidate factor for premature delivery. Conclusions: Gene type TT of MTHFR C677T polymorphism might make premature delivery risk rise while gene type CC of A1298C polymorphism might have protective influence on premature delivery. PMID:26261642

  4. Dietary consumption of B vitamins, maternal MTHFR polymorphisms and risk for spontaneous abortion

    PubMed Central

    Rodríguez-Guillén, María del Rosario; Torres-Sánchez, Luisa; Chen, Jia; Galván-Portillo, Marcia; Silva-Zolezzi, Irma; Blanco-Muñoz, Julia; Hernández-Valero, María A.; López-Carrillo, Lizbeth

    2010-01-01

    Objective To asses he association between intake of folate and B vitamins and the incidence of spontaneous abortion (SA) according to the maternal methylenetetrahydrofolate reductase (MTHFR) polymorphisms (677 C>T and 1298 A>C). Material and Methods We conducted a nested case-control study within a perinatal cohort of women recruited in the state of Morelos, Mexico. Twenty-three women with SA were compared to 74 women whose pregnancy survived beyond week 20th. Intake of folate and B vitamins respectively, was estimated using a validated food frequency questionnaire. Maternal MTHFR polymorphisms were determined by PCR-RFLP and serum homocysteine levels by HPLC. Results Carriers of MTHFR 677TT and 1298AC genotypes respectively showed an increased risk of SA (OR 677TT vs. CC/CT=5.0; 95% CI: 1.2, 20.9 and OR 1298 AC vs. AA=5.5; 95% CI: 1.1, 26.6). Conclusions Our results support the role of MTHFR polymorphisms as a risk factor for SA, regardless of dietary intake of B vitamins. PMID:19180309

  5. Association between the MTHFR C677T gene polymorphism and essential hypertension in South West Cameroon.

    PubMed

    Ghogomu, S M; Ngolle, N E; Mouliom, R N; Asa, B F

    2016-01-01

    The association of the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism and essential hypertension has been reported but with controversial results in diverse populations in Asia and Europe, thereby suggesting a dependency on ethnicity. The aim of this study was to investigate the association between the MTHFR C677T polymorphism and essential hypertension in a Cameroonian population (Bantu ethnic group) of the South West Region. Analysis of anthropometric and biochemical data in hypertensive and normotensive subjects revealed that age, systolic blood pressure, diastolic blood pressure, low-density lipoprotein cholesterol, serum total cholesterol, and triglycerides are independent risk factors for essential hypertension. Substitution of thymine for cytosine at position 667 of the MTHFR gene was determined by polymerase chain reaction-restriction fragment length polymorphism. Genotype frequencies were found to be 7.3% CC, 58.5% CT, and 34.1% TT for hypertensive subjects compared to 90.0% CC, 10.0% CT, and 0.0% TT for normotensives. Allele frequencies were obtained as 36.6% C and 63.4% T for hypertensive subjects and 95.0% C and 5.0% T for normotensive subjects. These results reveal that the T allele predisposes individuals to hypertension. Therefore, there is an association between variants of the MTHFR gene and hypertension in Cameroonian patients from the South West region. PMID:27051013

  6. Try235Phe homozygous mutation of the steroid 5-a reductase type 2 (SRD5A2) gene in a Turkish patient.

    PubMed

    Parlak, Mesut; Durmaz, Erdem; Gursoy, Semin; Bircan, Iffet; Akcurin, Sema

    2014-01-01

    Steroid 5-a reductase type 2 isoenzyme (SRD5A2) deficiency is a male-limited autosomal recessive disorder that results in decreased conversion of testosterone to dihydrotestosterone with various de.gree of incomplete virilization in affected 46, XY infants. No clear genotype-phenotype relationship has been reported till date; moreover, the same mutation can result in considerable heterogeneity in clinical manifestations. Of 6 documented cases with Try235Phe homozygous mutation of the SRD5A2 gene, 3 patients had predominantly female external genitalia whereas the other 3 had predominantly male phenotype. We report Try235Phe homozygous mutation of the SRD5A2 gene in a Turkish patient who was initially assigned as a girl because of the predominantly female appearance of the external genitalia. PMID:25266188

  7. Polymorphisms in MTHFR, MS and CBS Genes and Homocysteine Levels in a Pakistani Population

    PubMed Central

    Yakub, Mohsin; Moti, Naushad; Parveen, Siddiqa; Chaudhry, Bushra; Azam, Iqbal; Iqbal, Mohammad Perwaiz

    2012-01-01

    Background Hyperhomocysteinemia (>15 µmol/L) is highly prevalent in South Asian populations including Pakistan. In order to investigate the genetic determinants of this condition, we studied 6 polymorphisms in genes of 3 enzymes - methylenetetrahydrofolate reductase (MTHFR; C677T; A1298C), methionine synthase (MS; A2756G), cystathionine-β-synthase (CBS; T833C/844ins68, G919A) involved in homocysteine metabolism and investigated their interactions with nutritional and environmental factors in a Pakistani population. Methodology/Principal Findings In a cross-sectional survey, 872 healthy adults (355 males and 517 females; age 18–60 years) were recruited from a low-income urban population in Karachi. Fasting venous blood was obtained and assessed for plasma/serum homocysteine; folate, vitamin B12, pyridoxal phosphate and blood lead. DNA was isolated and genotyping was performed by PCR-RFLP (restriction-fragment-length- polymorphism) based assays. The average changes in homocysteine levels for MTHFR 677CT and TT genotypes were positive [β(SE β), 2.01(0.63) and 16.19(1.8) µmol/L, respectively]. Contrary to MTHFR C677T polymorphism, the average changes in plasma homocysteine levels for MS 2756AG and GG variants were negative [β(SE β), −0.56(0.58) and −0.83(0.99) µmol/L, respectively]. The average change occurring for CBS 844ins68 heterozygous genotype (ancestral/insertion) was −1.88(0.81) µmol/L. The combined effect of MTHFR C677T, MS A2756G and CBS 844ins68 genotypes for plasma homocysteine levels was additive (p value <0.001). Odds of having hyperhomocysteinemia with MTHFR 677TT genotype was 10-fold compared to MTHFR 677CC genotype [OR (95%CI); 10.17(3.6–28.67)]. Protective effect towards hyperhomocysteinemia was observed with heterozygous (ancestral/insertion) genotype of CBS 844ins68 compared to homozygous ancestral type [OR (95% CI); 0.58 (0.34–0.99)]. Individuals with MTHFR 677CT or TT genotypes were at a greater risk of hyperhomocysteinemia in

  8. Risk Factors for Colon Cancer in Northeastern Thailand: Interaction of MTHFR Codon 677 and 1298 Genotypes with Environmental Factors

    PubMed Central

    Promthet, Supannee Sriamporn; Pientong, Chamsai; Ekalaksananan, Tipaya; Wiangnon, Surapon; Poomphakwaen, Kirati; Songserm, Nopparat; Chopjitt, Peechanika; Moore, Malcolm A; Tokudome, Shinkan

    2010-01-01

    Background Polymorphisms in methylenetetrahydrofolate reductase (MTHFR), such as MTHFR C677T and A1298C, are associated with several cancers. This study aimed to evaluate the effects of MTHFR polymorphisms on colon cancer risk and possible interactions with environmental factors in a population from northeastern Thailand. Methods This hospital-based case–control study was conducted during 2002–2006; 130 colon cancer cases and 130 age- and sex-matched controls were enrolled. Information was collected and blood samples were obtained for assay of MTHFR C677T and A1298C polymorphisms by polymerase chain reaction with restriction fragment length polymorphism techniques. Associations between variables of interest and colon cancer were assessed using conditional logistic regression. Results Increased risk of colon cancer was associated with alcohol consumption and bowel habits. Alcohol drinkers who consumed ≤0.50 or >0.50 units of alcohol per day had elevated risks (ORadj = 3.5; 95% CI: 1.19–10.25 and ORadj = 1.71; 95% CI: 0.74–3.96, respectively). The risk was also higher in subjects with frequent constipation (11.69; 2.18–62.79) and occasional constipation (3.43; 1.72–6.82). An interaction was observed between the MTHFR C677T polymorphism and freshwater fish consumption on colon cancer risk (P value for interaction = 0.031). Interactions were observed between the MTHFR A1298C polymorphism and bowel habits, family history of cancer, alcohol consumption, and beef consumption on colon cancer risk (P-value for interaction = 0.0005, 0.007, 0.067, 0.003, respectively). Conclusions In a Thai population, colon cancer risk was associated with alcohol and beef consumption, bowel habits, and family history of cancer. Interactions between MTHFR polymorphisms and environmental factors were also observed. PMID:20551579

  9. Molecular basis of recessive congenital methemoglobinemia, types I and II: Exon skipping and three novel missense mutations in the NADH-cytochrome b5 reductase (diaphorase 1) gene.

    PubMed

    Kugler, W; Pekrun, A; Laspe, P; Erdlenbruch, B; Lakomek, M

    2001-04-01

    Hereditary methemoglobinemia due to reduced nicotin amide adenine dinucleotide (NADH)-cytochrome b5 reductase (b5r) deficiency is classified into an erythrocyte type (I) and a generalized type (II). We investigated the b5r gene of three unrelated patients with types I and II and found four novel mutations. The patient with type I was homozygous for a c.535 G-->A exchange in exon 6 (A179T). The patients with type II were found to be homozygous for a c.757 G-->A transition in exon 9 (V253M) and compound heterozygous for two mutations, respectively. One allele presented a c.379 A-->G transition (M127V). The second allele carried a sequence difference at the invariant 3' splice-acceptor dinucleotide of intron 4 (IVS4-2A-->G) resulting in skipping of exon 5. To characterize a possible effect of this mutation on RNA metabolism, poly(A)(+) RNA was analyzed by RT-PCR and sequencing. The results show that RNA is made from the allele harboring the 3'-splice site mutation. Furthermore, western blot analysis revealed a complete absence of immunologically detectable b5r in skin fibroblasts of this patient. The compound heterozygosity for the splice site and the missense mutations apparently caused hereditary methemoglobinemia type II in this patient. Hum Mutat 17:348, 2001. PMID:11295830

  10. A Study on MTHFR C677T Gene Polymorphism and Alcohol Dependence among Meiteis of Manipur, India

    PubMed Central

    Singh, Huidrom Suraj; Salam, Kabita; Saraswathy, Kallur Nava

    2014-01-01

    Chronic alcohol consumption is reported to be associated with increase in plasma homocysteine levels which is further influenced by the polymorphism in methylenetetrahydrofolate reductase (MTHFR) gene. The present study aims to understand the extent of the MTHFR C677T polymorphism in alcohol dependent (AD) cases of Meiteis of Manipur, a Mendelian population of India. MTHFR C677T polymorphism was screened in 313 controls and 139 alcohol dependent (AD) cases who all met DSM-IV criteria for alcohol dependence. Both AD cases and controls were unrelated up to 1st cousin. Among the control group, different drinking patterns like abstainer/nondrinkers (NDs), occasional drinkers (ODs), and moderate drinkers (MDs) are included. Both the groups were found to be in Hardy-Weinberg equilibrium (P > 0.05). Genotypic and allelic frequency distribution of MTHFR C677T polymorphism did not differ significantly between AD cases and controls (P > 0.05). However, individuals carrying mutant (T) allele show more than 1-fold increased risk for AD though not significant (OR = 1.43; 95% CI 0.41–5.01, P > 0.05). In conclusion, MTHFR C677T polymorphism is not found to be risk marker for AD in present studied population. However, higher prevalence of the mutant T allele may exacerbate deleterious health risk in future especially among alcohol drinkers. PMID:26317030

  11. Dietary intake of folate and co-factors in folate metabolism, MTHFR polymorphisms, and reduced rectal cancer.

    PubMed

    Murtaugh, Maureen A; Curtin, Karen; Sweeney, Carol; Wolff, Roger K; Holubkov, Richard; Caan, Bette J; Slattery, Martha L

    2007-03-01

    Little is known about the contribution of polymorphisms in the methylenetetrahydrofolate reductase gene (MTHFR) and the folate metabolism pathway in rectal cancer alone. Data were from participants in a case-control study conducted in Northern California and Utah (751 cases and 979 controls). We examined independent associations and interactions of folate, B vitamins, methionine, alcohol, and MTHFR polymorphisms (MTHFR C677T and A1298C) with rectal cancer. Dietary folate intake was associated with a reduction in rectal cancer OR 0.66, 95% CI 0.48-0.92 (>475 mcg day compared to < or = 322 mcg) as was a combination of nutrient intakes contributing to higher methyl donor status (OR 0.79, 95% CI 0.66-0.95). Risk was reduced among women with the 677 TT genotype (OR 0.54, 95% CI 0.30-0.9), but not men (OR 1.11, 95% CI 0.70-1.76) and with the 1298 CC genotype in combined gender analysis (OR 0.67, 95% CI 0.46-0.98). These data are consistent with a protective effect of increasing dietary folate against rectal cancer and suggest a protective role of the MTHFR 677 TT genotype in women and 1298 CC in men and women. Folate intake, low methyl donor status, and MTHFR polymorphisms may play independent roles in the etiology of rectal cancer. PMID:17245555

  12. Methotrexate-induced mucositis in acute leukemia patients is not associated with the MTHFR 677T allele in Mexico.

    PubMed

    Ruiz-Argüelles, Guillermo J; Coconi-Linares, Lucia Nancy; Garcés-Eisele, Javier; Reyes-Núñez, Virginia

    2007-10-01

    Methylenetetrahydrofolate reductase (MTHFR) has two common variants with reduced activity due to polymorphisms at nucleotides 677 and 1298. Both affect folate metabolism and thus remethylation of homocysteine, but are also thought to affect nucleotide synthesis and DNA methylation. Methotrexate (MTX), which interrupts folate metabolism, is used in the treatment of a variety of diseases including acute lymphoblastic leukemia (ALL), but exerts in some patients toxic effects on fast dividing tissues such as mucosal epithelia. The enhanced toxicity may be due to cooperative effects between MTX and MTHFR variants. Accordingly, it has been reported that carrying the 677T allele of the MTHFR is a risk factor for MTX-associated mucositis. As in the Mexican population, which is characterized by a high prevalence of the 677T MTHFR variant, several of its commonly associated defects have not been observed, we investigated the relationship between MTX toxicity and the 677T allele. Out of 28 patients with ALL (CC: 2, CT: 10, TT: 16), 16 had episodes of MTX-associated mucositis (CC: 0, CT: 6, TT: 10). Neither at the gene level nor at the genotype level was a significant association with mucositis found. It may be postulated that the risk of higher MTX toxicity in patients with decreased MTHFR activity could be neutralized by the normally folate rich diet in Mexico. PMID:17891601

  13. Prevalence of MTHFR C677T and MS A2756G polymorphisms in major depressive disorder, and their impact on response to fluoxetine treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine the prevalence of the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and the A2756G polymorphism of methionine synthase (MS), and their impact on antidepressant response. We screened 224 subjects (52% female, mean age 39 +/- 11 years) with SCID-diagnosed major...

  14. Genetics Home Reference: 5-alpha reductase deficiency

    MedlinePlus

    ... gene provides instructions for making an enzyme called steroid 5-alpha reductase 2. This enzyme is involved ... external genitalia. Mutations in the SRD5A2 gene prevent steroid 5-alpha reductase 2 from effectively converting testosterone ...

  15. Polymorphisms in the methylene tetrahydrofolate reductase and methionine synthase reductase genes and their correlation with unexplained recurrent spontaneous abortion susceptibility.

    PubMed

    Zhu, L

    2015-01-01

    We aimed to explore the correlation between unexplained recurrent spontaneous abortion and polymorphisms in the methylene tetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genes. A case control study was conducted in 118 patients with unexplained recurrent spontaneous abortion (abortion group) and 174 healthy women (control group). The genetic material was extracted from the oral mucosal epithelial cells obtained from all subjects. The samples were subjected to fluorescence quantitative PCR to detect the single nucleotide polymorphisms (SNPs) in the MTHFR (C677T and A1298C) and MTRR (A66G) gene loci. The distribution frequency (18/118, 15.3%) of the MTHFR 677TT genotype was significantly higher in the abortion group (χ2 = 11.006, P = 0.004) than in the control group (2/174, 1.1%); on the other hand, the distribution frequency of the MTHFR A1298C genotype did not significantly differ between the abortion and control groups (χ(2) = 0.441, P = 0.507). The distribution frequency of the MTRR A66G genotype was also significantly higher in the abortion group (14/118, 11.9%; χ(2) = 10.503, P = 0.005) than in the control group (8/174, 4.6%). The MTHFR C677T and MTRR A66G polymorphisms are significantly correlated with the occurrence of spontaneous abortion. PMID:26345779

  16. Status of vitamin B-12 and B-6 but not of folate, homocysteine and the methylenetetrahydrofolate reductase C677T polymorphism are associated with impaired cognition and depression in adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene differs in frequency in different ethnic groups which have differing prevalence of age-related cognitive impairments. We used a battery of neuropsychological tests to examine association of the MTHFR C677T polymorphism w...

  17. Association between MTHFR gene polymorphisms and the risk of autism spectrum disorders: a meta-analysis.

    PubMed

    Pu, Danhua; Shen, Yiping; Wu, Jie

    2013-10-01

    Methylenetetrahydrofolate reductase (MTHFR) is essential for DNA biosynthesis and the epigenetic process of DNA methylation, and its gene polymorphisms have been implicated as risk factors for birth defects, neurological disorders, and cancers. However, reports on the association of MTHFR polymorphisms with autism spectrum disorders (ASD) are inconclusive. Therefore, we investigated the relationship of the MTHFR polymorphisms (C677T and A1298C) and the risk of ASD by meta-analysis. Up to December 2012, eight case-control studies involving 1672 patients with ASD and 6760 controls were included for meta-analysis. The results showed that the C677T polymorphism was associated with significantly increased ASD risk in all the comparison models [T vs. C allele (frequency of allele): odds ratio (OR) = 1.42, 95% confidence interval (CI): 1.09-1.85; CT vs. CC (heterozygote): OR = 1.48, 95% CI: 1.09-2.00; TT vs. CC (homozygote): OR = 1.86, 95% CI: 1.08-3.20; CT+TT vs. CC (dominant model): OR = 1.56, 95% CI: 1.12-2.18; and TT vs. CC+CT (recessive model): OR = 1.51, 95% CI: 1.02-2.22], whereas the A1298C polymorphism was found to be significantly associated with reduced ASD risk but only in a recessive model (CC vs. AA+AC: OR = 0.73, 95% CI: 0.56-0.97). In addition, we stratified the patient population based on whether they were from a country with food fortification of folic acid or not. The meta-analysis showed that the C677T polymorphism was found to be associated with ASD only in children from countries without food fortification. Our study indicated that the MTHFR C677T polymorphism contributes to increased ASD risk, and periconceptional folic acid may reduce ASD risk in those with MTHFR 677C>T polymorphism. PMID:23653228

  18. Postgraduate Symposium: The MTHFR C677T polymorphism, B-vitamins and blood pressure.

    PubMed

    Wilson, C P; McNulty, H; Scott, J M; Strain, J J; Ward, M

    2010-02-01

    High blood pressure (BP) and elevated homocysteine are reported as independent risk factors for CVD and stroke in particular. The main genetic determinant of homocysteine concentrations is homozygosity (TT genotype) for the C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene, typically found in approximately 10% of Western populations. The B-vitamins folate, vitamin B12 and vitamin B6 are the main nutritional determinants of homocysteine, with riboflavin more recently identified as a potent modulator specifically in individuals with the TT genotype. Although observational studies have reported associations between homocysteine and BP, B-vitamin intervention studies have shown little or no BP response despite decreases in homocysteine. Such studies, however, have not considered the MTHFR C677T polymorphism, which has been shown to be associated with BP. It has been shown for the first time that riboflavin is an important determinant of BP specifically in individuals with the TT genotype. Research generally suggests that 24 h ambulatory BP monitoring provides a more accurate measure of BP than casual measurements and its use in future studies may also provide important insights into the relationship between the MTHFR polymorphism and BP. Further research is also required to investigate the association between specific B-vitamins and BP in individuals with different MTHFR genotypes in order to confirm whether any genetic predisposition to hypertension is correctable by B-vitamin intervention. The present review will investigate the evidence linking the MTHFR C677T polymorphism to BP and the potential modulating role of B-vitamins. PMID:19954568

  19. Meta-analysis of associations between MTHFR and GST polymorphisms and susceptibility to multiple sclerosis.

    PubMed

    Lee, Young Ho; Seo, Young Ho; Kim, Jae-Hoon; Choi, Sung Jae; Ji, Jong Dae; Song, Gwan Gyu

    2015-11-01

    We examined whether methylenetetrahydrofolate reductase (MTHFR) and glutathione S-transferase (GST) polymorphisms are associated with susceptibility to multiple sclerosis (MS). We performed a meta-analysis on the association between MS and the following genotypes: MTHFR C677T, A1298C, and GSTP1 A313G polymorphisms, and GSTM1 and GSTT1 null alleles. Fifteen comparisons involving 2,486 patients and 2,861 controls were considered. Meta-analysis of all study subjects considered together showed no association between MS and the MTHFR 677 T allele (OR = 1.014, 95 % CI 0.803-1.280, p = 0.909). Stratification by ethnicity showed no similar association in Caucasian and Arab populations. Likewise, no link was found between MS and the MTHFR 1298 C allele in the total data (OR = 2.477, 95 % CI 0.507-12.10, p = 0.263), nor when it was stratified by ethnicity. No association with MS was observed in relation to the GSTM1 null genotype in Caucasian populations (OR = 1.229, 95 % CI 0.693-2.181, p = 0.481), nor with the GSTP1 A313G polymorphism (OR for G allele = 1.133, 95 % CI 0.903-1.421, p = 0.281). However, there was an association between MS and the GSTT1 null genotype in data obtained from Caucasian populations (OR = 1.945, 95 % CI 1.452-2.605, p = 8.6 × 10(-7)). GSTT1 null genotype is associated with MS in Caucasian populations; however, no association was found between MS and polymorphisms of MTHFR, GSTM1, and GSTP1. PMID:26150166

  20. Association of MTHFR A1298C polymorphism with conotruncal heart disease.

    PubMed

    Sayin Kocakap, Beyza D; Sanli, Cihat; Cabuk, Feryal; Koc, Murat; Kutsal, Ali

    2015-10-01

    Congenital heart diseases are common congenital anomalies with 1% prevalence worldwide and are associated with significant childhood morbidity and mortality. Among a wide range of aetiologically heterogeneous conditions, conotruncal anomalies account for approximately one-third of all congenital heart defects. The aetiology of conotruncal heart diseases is complex, with both environmental and genetic causes. Hyperhomocysteinaemia, which is often accompanied by the defects of folic acid metabolism, is known to cause conotruncal heart anomalies. In this study, we have evaluated three polymorphisms in the following two hyperhomocysteinaemia-related genes: methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and nicotinamide N-methyl transferase (NNMT rs694539) in 79 children with conotruncal heart disease and 99 children without conotruncal heart disease. Genotype distribution of the MTHFR A1298C polymorphism showed a statistically significant difference between the two groups. In the case group, AC and CC genotypes were higher than the control group (p<0.05). We have found that MTHFR A1298C polymorphism is associated with conotruncal heart disease; C allele (p=0.028), AC (OR[95% CI]=2.48[1.24-4.95], p=0.010), CC (OR[95% CI]=3.01[1.16-7.83], p=0.023), and AC+CC (OR[95% CI]=2.60[1.36-4.99], p=0.004) genotypes are more frequent in the patient group. Genotype distributions of the MTHFR C677T and NNMT rs694539 polymorphisms were similar in the two groups when evaluated separately and also according to the dominant genetic model (p>0.05). Our results suggest that MTHFR 1298C allele is a risk factor for conotruncal heart disease. PMID:25547204

  1. Riboflavin status, MTHFR genotype and blood pressure: current evidence and implications for personalised nutrition.

    PubMed

    McAuley, E; McNulty, H; Hughes, C; Strain, J J; Ward, M

    2016-08-01

    Clinical deficiency of the B-vitamin riboflavin (vitamin B2) is largely confined to developing countries; however accumulating evidence indicates that suboptimal riboflavin status is a widespread problem across the developed world. Few international data are available on riboflavin status as measured by the functional biomarker, erythrocyte glutathione reductase activation coefficient, considered to be the gold standard index. One important role of riboflavin in the form of flavin dinucleotide is as a co-factor for the folate-metabolising enzyme methylenetetrahydrofolate reductase (MTHFR). Homozygosity for the common C677T polymorphism in MTHFR, affecting over 10 % of the UK and Irish populations and up to 32 % of other populations worldwide, has been associated with an increased risk of CVD, and more recently with hypertension. This review will explore available studies reporting riboflavin status worldwide, the interaction of riboflavin with the MTHFR C677T polymorphism and the potential role of riboflavin in personalised nutrition. Evidence is accumulating for a novel role of riboflavin as an important modulator of blood pressure (BP) specifically in individuals with the MTHFR 677TT genotype, with results from a number of recent randomised controlled trials demonstrating that riboflavin supplementation can significantly reduce systolic BP by 5-13 mmHg in these genetically at risk adults. Studies are however required to investigate the BP-lowering effect of riboflavin in different populations and in response to doses higher than 1·6 mg/d. Furthermore, work focusing on the translation of this research to health professionals and patients is also required. PMID:27170501

  2. Screening of polymorphisms for MTHFR and DHFR genes in spina bifida children and their mothers

    NASA Astrophysics Data System (ADS)

    Husna, M. Z.; Endom, I.; Ibrahim, S.; Selvi, N. Amaramalar; Fakhrurazi, H.; Htwe, R. Ohnmar; Kanehaswari, Y.; Halim, A. R. Abdul; Wong, S. W.; Subashini, K.; Syahira, O. Nur; Aishah, S.

    2013-11-01

    Mechanism underlying the beneficial effect of folic acid supplementation in reducing the risk of neural tube defect is still not well understood. Current evidences show the involvement of folic acid metabolic gene's polymorphism as contributing factors that regulate this pathway. Therefore, the objective of this research was to determine the presence of C677T polymorphism for methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR-19 bp deletion) genes between mother-children pairs of case and control. With the approval of UKMMC ethic committee, genomic DNA was extracted from one hundred and forty consented bloods. Polymerase chain reaction (PCR), PCR-RFLP (Restriction Fragment Length Polymorphism) and sequencing were employed to verify each nucleotide change. Our result shows that mutant MTHFR and DHFR alleles are present in all Malaysian sub-ethnic groups, case and control. Even though mutant MTHFR are found to be slightly higher in the case groups, 75% of the affected child is a non carrier for this allele and 62.5% of the mothers with an affected child are genotypically normal. For DHFR, almost all (87.5-100%) investigated samples are a carrier or having a double DHFR deletion be it a case or control pairs. However, strong maternal inheritance shown by the deleted allele might be due to a cascade effect of lacks of folate consumption or maternal uniparental disomy. In conclusion, the use of MTHFR and DHFR as markers in determining the risk of having spina bifida baby is uninformative and plays a small indirect role as the genetic causes of spina bifida. Therefore, spina bifida remains etiologically unknown polygenic and quantitative developmental trait whereby the searches for positive genetic marker need to be continued.

  3. Thermolabile methylenetetrahydrofolate reductase: an inherited risk factor for coronary artery disease.

    PubMed Central

    Kang, S S; Wong, P W; Susmano, A; Sora, J; Norusis, M; Ruggie, N

    1991-01-01

    Severe methylenetetrahydrofolate reductase (MTHFR) deficiency with less than 2% of normal enzyme activity is characterized by neurological abnormalities, atherosclerotic changes, and thromboembolism. We have discovered a "new" variant of MTHFR deficiency which is characterized by the absence of neurological abnormalities, an enzyme activity of about 50% of the normal value, and distinctive thermolability under specific conditions of heat inactivation. In this study, lymphocyte MTHFR specific activities in the thermolabile variant and control groups were 5.58 +/- 0.91 and 10.33 +/- 2.89 nmol formaldehyde formed/mg protein/h, respectively. The difference was significant (P less than .01). However, there was overlap among the individual values from the two groups. On the other hand, residual MTHFR activity after heat inactivation was 11.2 +/- 1.43% in the thermolabile variant and 36.3 +/- 5.18% in the controls. There was no overlap. Enzyme studies in 10 subjects with thermolabile MTHFR and their family members support the hypothesis that thermolabile MTHFR is inherited as an autosomal recessive trait. To elucidate the association of thermolabile MTHFR with the development of coronary artery disease, we determined the thermostability of lymphocyte MTHFR in 212 patients with proven coronary artery disease and in 202 controls without clinical evidence of atherosclerotic vascular disease. Thermolabile MTHFR was found in 36 (17.0%) cardiac patients and 10 (5.0%) controls. The difference in incidence between the two groups was statistically significant (P less than .01). The average age at onset of clinical coronary artery disease in 36 patients with thermolabile MTHFR was 57.3 +/- 7.6 years (35-72 years). The mean total plasma homocysteine concentration in patients with thermolabile MTHFR was 13.19 +/- 5.32 nmol/ml and was significantly different from the normal mean of 8.50 +/- 2.80 nmol/ml (P less than .05). There was no association between thermolabile MTHFR and other

  4. Interaction of MTHFR C677T and A1298C, and MTR A2756G gene polymorphisms in breast cancer risk in a population in Northeast Brazil.

    PubMed

    de Cássia Carvalho Barbosa, Rita; da Costa, Débora Menezes; Cordeiro, Denise Ellen Francelino; Vieira, Ana Patricia Freitas; Rabenhorst, Silvia Helena Barem

    2012-11-01

    Polymorphisms in genes encoding enzymes of folate metabolism are a focus of breast cancer risk studies due of the role of these enzymes in DNA methylation, synthesis, and repair. MTHFR, encoding for 5,10-methylenetetrahydrofolate reductase, is one of the most studied genes in this regard, but findings are controversial, and the majority of studies have analyzed polymorphisms individually. In this case control study, we examined the combination of the polymorphisms MTHFR C677T and A1298C with MTR A2756G, where MTR, methionine synthase, is an important enzyme of the folate cycle in the methylation pathway. One hundred and forty-two patients with breast cancer and controls were included and the genotypes were determined using PCR-RFLP. In the population studied, individuals carrying the polymorphic allele in the heterozygous state for both enzymes, MTHFR C677T and MTR A2756G, had an increased risk [odds ratio, OR=2.77 (95% confidence interval, CI=1.19-6.52)] for disease, compared to those with the wild genotype. In addition, individuals carrying the MTR 2756 genotype AG had an increased risk when this was combined with the MTHFR 1298 genotype CC [OR=5.13 (95% CI=0.87-38.82)]. No significant results were found from the analyses associating the MTHFR C677T and A1298C genotypes. However, when stratifying the patients by age (50 years old as the cut-off), patients over 50 years old had greater risk, with the presence of both MTHFR polymorphisms in the heterozygous state [OR=5.33 (95% CI=1.42-21.03)]. This study points out the importance of the interactions between the MTHFR C677T, MTHFR A1298C and MTR A2756G polymorphisms, and also highlights the relevance of the MTR A2756G polymorphism and age in breast cancer risk. PMID:23155246

  5. Correction of point mutations at the endogenous locus of the dihydrofolate reductase gene using repair-PolyPurine Reverse Hoogsteen hairpins in mammalian cells.

    PubMed

    Solé, Anna; Ciudad, Carlos J; Chasin, Lawrence A; Noé, Véronique

    2016-06-15

    Correction of point mutations that lead to aberrant transcripts, often with pathological consequences, has been the focus of considerable research. In this work, repair-PPRHs are shown to be a new powerful tool for gene correction. A repair-PPRH consists of a PolyPurine Reverse Hoogsteen hairpin core bearing an extension sequence at one end, homologous to the DNA strand to be repaired but containing the wild type nucleotide instead of the mutation. Previously, we had corrected a single-point mutation with repair-PPRHs using a mutated version of a dihydrofolate reductase (dhfr) minigene. To further evaluate the utility of these molecules, different repair-PPRHs were designed to correct insertions, deletions, substitutions and a double substitution present in a collection of mutants at the endogenous locus of the dhfr gene, the product of which is the target of the chemotherapeutic agent methotrexate. We also describe an approach to use when the point mutation is far away from the homopyrimidine target domain. This strategy consists in designing Long-Distance- and Short-Distance-Repair-PPRHs where the PPRH core is bound to the repair tail by a five-thymidine linker. Surviving colonies in a DHFR selective medium, lacking glycine and sources of purines and thymidine, were analyzed by DNA sequencing, and by mRNA, protein and enzymatic measurements, confirming that all the dhfr mutants had been corrected. These results show that repair-PPRHs can be effective tools to accomplish a permanent correction of point mutations in the DNA sequence of mutant mammalian cells. PMID:27063945

  6. MTHFR 677C>T Polymorphism Increases the Male Infertility Risk: A Meta-Analysis Involving 26 Studies

    PubMed Central

    Gong, Mancheng; Dong, Wenjing; He, Tingyu; Shi, Zhirong; Huang, Guiying; Ren, Rui; Huang, Sichong; Qiu, Shaopeng; Yuan, Runqiang

    2015-01-01

    Background and Objectives Methylenetetrahydrofolate reductase (MTHFR) polymorphism may be a risk factor for male infertility. However, the epidemiologic studies showed inconsistent results regarding MTHFR polymorphism and the risk of male infertility. Therefore, we performed a meta-analysis of published case-control studies to re-examine the controversy. Methods Electronic searches of PubMed, EMBASE, Google Scholar and China National Knowledge Infrastructure (CNKI) were conducted to select eligible literatures for this meta-analysis (updated to June 19, 2014). According to our inclusion criteria and the Newcastle-Ottawa Scale (NOS), only high quality studies that observed the association between MTHFR polymorphism and male infertility risk were included. Crude odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of association between the MTHFR polymorphism and male infertility risk. Results Twenty-six studies involving 5,575 cases and 5,447 controls were recruited. Overall, MTHFR 677C>T polymorphism showed significant associations with male infertility risk in both fixed effects (CT+TT vs. CC: OR = 1.34, 95% CI: 1.23–1.46) and random effects models (CT+TT vs. CC: OR = 1.39, 95% CI: 1.19–1.62). Further, when stratified by ethnicity, sperm concentration and control sources, the similar results were observed in Asians, Caucasians, Azoo or OAT subgroup and both in population-based and hospital-based controls. Nevertheless, no significant association was only observed in oligo subgroup. Conclusions Our results indicated that the MTHFR polymorphism is associated with an increased risk of male infertility. Further well-designed analytical studies are necessary to confirm our conclusions and evaluate gene-environment interactions with male infertility risk. PMID:25793386

  7. Short Communication: Lack of association between MTHFR gene polymorphisms and response to methotrexate treatment in Pakistani patients with rheumatoid arthritis.

    PubMed

    Iqbal, Mohammad Perwaiz; Ali, Azra Arif; Mehboobali, Naseema; Iqbal, Khalida

    2015-09-01

    Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms have been reported to be associated with response to methotrexate (MTX) in certain populations of patients with rheumatoid arthritis (RA). This study aims at investigating any relationship of two single nucleotide polymorphisms (SNPs) in MTHFR gene, C677T and A1298C with response to therapy with MTX in Pakistani RA patients. Allelic frequencies of the two polymorphisms (C677T and A1298C) were determined in 67 RA patients (9 males and 58 females; mean age 42.87 ± 13.5 years) who had previously participated in a prospective clinical trial. Fifty-one patients had received MTX and were followed up for response up to 6 months. Genotyping of the two MTHFR polymorphisms was carried out using PCR-RFLP, while fasting concentration of plasma homocysteine was determined using a kit method. Twenty-eight patients were found to be "good responders", while twenty-three were "poor responders". MTHFR 1298C and MTHFR 677T alleles' frequencies in "good responders" were not different from frequencies in "poor responders" (0.574 vs. 0.521; p=0.6 and 0.197 vs. 0.196; p=0.75, respectively). Plasma homocysteine levels in female RA patients were significantly higher compared to general population in Karachi (13.1 ± 6.7 µmol/l vs. 11.4 ± 5.3 µmol/l; p<0.001). MTHFR C677T and A1298C polymorphisms are not associated with response to MTX in a population of Pakistani RA patients. PMID:26408898

  8. Methylenetetrahydrofolate reductase genotypes and haplotypes associated with susceptibility to colorectal cancer in an eastern Chinese Han population.

    PubMed

    Li, H; Xu, W L; Shen, H L; Chen, Q Y; Hui, L L; Long, L L; Zhu, X L

    2011-01-01

    Methylenetetrahydrofolate reductase (MTHFR) plays an important role in folate metabolism and is involved in DNA synthesis, DNA repair and DNA methylation. The two common functional polymorphisms of MTHFR, C677T and A1298C have been associated with several diseases, including cancer. We made a case-control study to analyze a possible association of MTHFR gene polymorphisms C677T and A1298C with risk for colorectal cancer in an eastern Chinese Han population of 137 patients with a confirmed histopathological diagnosis of CRC and 145 age- and gender-matched controls with no history of cancer. DNA was isolated from peripheral blood samples and the genotypes were determined by PCR-RFLP. The concentrations of folate in plasma were measured by chemiluminescence immunoassay. The MTHFR 677TT genotype had a protective effect against colorectal cancer, with an odds ratio (OR) = 0.467 (95% confidence interval (CI) = 0.225-0.966). The 1298CC genotype was significantly correlated with a reduced risk of colorectal cancer (OR = 0.192; 95%CI = 0.040-0.916). Compared with the MTHFR 677CC and MTHFR 1298 AA genotypes, for individuals who carried both MTHFR 677CC and 1298CC genotypes, the OR of colorectal cancer was 0.103 (95%CI = 0.012-0.900); among individuals who carried both MTHFR 677TT and 1298AC genotypes, the OR for risk of colorectal cancer was 0.169 (95%CI = 0.044-0.654). MTHFR 677TT+CT genotypes had a significantly lower plasma folate concentration than those with the MTHFR 677CC genotype. MTHFR 1298AC+CC genotypes had a lower plasma folate concentration than those with the MTHFR 1298AA genotype (P < 0.05). In conclusion, subjects with the MTHFR 677TT and MTHFR 1298CC genotypes appeared to have a significantly lower risk for colorectal cancer. MTHFR haplotypes 677CC/1298CC and 677TT/1298AC were less common in cases than in controls. These haplotypes, when compared to the most common haplotype 677CC/1298AA, were associated with a decreased risk for colorectal cancer. We

  9. Associations of Polymorphisms in MTHFR Gene with the Risk of Age-Related Cataract in Chinese Han Population: A Genotype-Phenotype Analysis

    PubMed Central

    Wei, Li; Han, Ya-di; Cui, Ning-hua; Huang, Zhu-liang; Li, Zu-hua; Zheng, Fang; Yan, Ming

    2015-01-01

    Homocysteine (Hcy) is a potential risk factor for age-related cataract (ARC). Methylenetetrahydrofolate reductase (MTHFR) is the key enzyme for Hcy metabolism, and variants of MTHFR may affect MTHFR enzyme activity. This study mainly evaluated the associations between variants in MTHFR gene, plasma MTHFR enzyme activity, total Hcy (tHcy) levels and ARC risk in Chinese population. Four single nucleotide polymorphisms (SNPs) in MTHFR gene were genotyped using the high-resolution melting (HRM) method in 502 ARC patients (mean age, 70.2 [SD, 9.0], 46.0% male) and 890 healthy controls (mean age, 67.1 [SD, 11.1], 47.6% male). The plasma MTHFR activity, folic acid (FA), vitamins B12 and B6 levels were detected by enzyme-linked immunosorbent assays (ELISA). The plasma tHcy levels were measured by an automated enzymatic assay. After the Bonferroni correction, the minor allele T of SNP rs1801133 showed a significant association with an increased risk of overall ARC (OR = 1.26, P = 0.003). Consistent association was also found between SNP rs1801133 and cortical ARC risk (OR = 1.44, P = 0.003). Haplotype analyses revealed an adverse effect of the haplotype "C-A-T-C" (alleles in order of SNPs rs3737967, rs1801131, rs1801133 and rs9651118) on ARC risk (OR = 1.55, P = 0.003). Moreover, in a joint analysis of SNPs rs9651118 and rs1801133, subjects with two unfavorable genotypes had a 1.76-fold increased risk of ARC compared with the reference group, and a statistically significant dose-response trend (Ptrend = 0.001) was also observed. Further, in healthy controls and patients with cortical ARC, the allele T of SNP rs1801133 and the increasing number of unfavorable genotypes were significantly correlated with decreased MTHFR activity as well as increased tHcy levels. However, there was no significant association between FA, vitamins B12, B6 levels and MTHFR variants. Our data indicated that variants in MTHFR gene might individually and jointly influence susceptibility to ARC by

  10. Dihydrofolate-Reductase Mutations in Plasmodium knowlesi Appear Unrelated to Selective Drug Pressure from Putative Human-To-Human Transmission in Sabah, Malaysia

    PubMed Central

    Imwong, Mallika; William, Timothy; Bird, Elspeth; Piera, Kim A.; Aziz, Ammar; Boonyuen, Usa; Drakeley, Christopher J.; Cox, Jonathan; White, Nicholas J.; Cheng, Qin; Yeo, Tsin W.; Auburn, Sarah; Anstey, Nicholas M.

    2016-01-01

    Background Malaria caused by zoonotic Plasmodium knowlesi is an emerging threat in Eastern Malaysia. Despite demonstrated vector competency, it is unknown whether human-to-human (H-H) transmission is occurring naturally. We sought evidence of drug selection pressure from the antimalarial sulfadoxine-pyrimethamine (SP) as a potential marker of H-H transmission. Methods The P. knowlesi dihdyrofolate-reductase (pkdhfr) gene was sequenced from 449 P. knowlesi malaria cases from Sabah (Malaysian Borneo) and genotypes evaluated for association with clinical and epidemiological factors. Homology modelling using the pvdhfr template was used to assess the effect of pkdhfr mutations on the pyrimethamine binding pocket. Results Fourteen non-synonymous mutations were detected, with the most common being at codon T91P (10.2%) and R34L (10.0%), resulting in 21 different genotypes, including the wild-type, 14 single mutants, and six double mutants. One third of the P. knowlesi infections were with pkdhfr mutants; 145 (32%) patients had single mutants and 14 (3%) had double-mutants. In contrast, among the 47 P. falciparum isolates sequenced, three pfdhfr genotypes were found, with the double mutant 108N+59R being fixed and the triple mutants 108N+59R+51I and 108N+59R+164L occurring with frequencies of 4% and 8%, respectively. Two non-random spatio-temporal clusters were identified with pkdhfr genotypes. There was no association between pkdhfr mutations and hyperparasitaemia or malaria severity, both hypothesized to be indicators of H-H transmission. The orthologous loci associated with resistance in P. falciparum were not mutated in pkdhfr. Subsequent homology modelling of pkdhfr revealed gene loci 13, 53, 120, and 173 as being critical for pyrimethamine binding, however, there were no mutations at these sites among the 449 P. knowlesi isolates. Conclusion Although moderate diversity was observed in pkdhfr in Sabah, there was no evidence this reflected selective antifolate drug

  11. MTHFR gene polymorphism and risk of myeloid leukemia: a meta-analysis.

    PubMed

    Dong, Song; Liu, Yueling; Chen, Jieping

    2014-09-01

    An increasing body of evidence has shown that the amino acid changes at position 1298 might eliminate methylenetetrahydrofolate reductase (MTHFR) enzyme activity, leading to insufficient folic acid and subsequent human chromosome breakage. Epidemiological studies have linked MTHFR single-nucleotide polymorphism (SNP) rs1801131 to myeloid leukemia risk, with considerable discrepancy in their results. We therefore were prompted to clarify this issue by use of a meta-analysis. The search terms were used to cover the possible reports in the MEDLINE, Web of Knowledge, and China National Knowledge Infrastructure (CNKI) databases. Odds ratios were estimated to assess the association of SNP rs1801131 with myeloid leukemia risk. Statistical heterogeneity was detected using the Q-statistic and I (2) metric. Subgroup analysis was performed by ethnicity, histological subtype, and Hardy-Weinberg equilibrium (HWE). This meta-analysis of eight publications with a total of 1,114 cases and 3,227 controls revealed no global association. Nor did the subgroup analysis according to histological subtype and HWE show any significant associations. However, Asian individuals who harbored the CC genotype were found to have 1.66-fold higher risk of myeloid leukemia (odds ratio, 1.66; 95 % confidence interval, 1.10 to 2.49; P h = 0.342; I (2) = 0.114). Our meta-analysis has presented evidence supporting a possible association between the CC genotype of MTHFR SNP rs1801131 and myeloid leukemia in Asian populations. PMID:24894669

  12. High homocysteine and epistasis between MTHFR and APOE: association with cognitive performance in the elderly.

    PubMed

    Polito, Letizia; Poloni, Tino Emanuele; Vaccaro, Roberta; Abbondanza, Simona; Mangieri, Michela; Davin, Annalisa; Villani, Simona; Guaita, Antonio

    2016-04-01

    High total homocysteine (tHcy) is associated with cognitive impairment in the elderly. The impact of high tHcy on different cognitive domains deserves further investigation, as does the role of the C677T polymorphism of the 5,10 methylenetetrahydrofolate reductase (MTHFR) gene. A cross-sectional analysis of 903 subjects from the population-based "InveCe.Ab" study was performed. The participants had no psychosis or active neurological disorders. They underwent a neuropsychological assessment. Principal component analysis allowed cognitive performance to be condensed into two components: executive functions and memory. Novel components were evaluated for association with tHcy, controlling for potential confounders. Regression models showed that high serum tHcy was associated with lower executive functions, but not with memory. MTHFR C677T TT was associated with higher tHcy but did not affect cognitive performance per se. However, when combined with the apolipoprotein E (APOE)-ε4 allele, it was a risk factor for lower executive performance, independently of tHcy levels. In summary, high tHcy per se, or MTHFR C677T TT in combination with the APOE-ε4 allele, might be associated primarily with executive dysfunctions rather than memory loss. PMID:26774227

  13. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and nonsyndromic orofacial clefts susceptibility in a southern Chinese population.

    PubMed

    Han, Yue; Pan, Yongchu; Du, Yifei; Tong, Na; Wang, Meilin; Zhang, Zhengdong; Wan, Linzhong; Wang, Lin

    2011-12-01

    Nonsyndromic orofacial clefts (NSOC) are one of the most common congenital anomalies in humans. Great efforts have been taken to unravel its genetic background. Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme in folate metabolism and two of its functional polymorphisms, MTHFR C677T and MTHFR A1298C, might be associated with NSOC susceptibility. The aim of the present study was to investigate their associations with risks of NSOC in a southern Chinese population. We found that MTHFR 677 TT and 677 CT/TT were associated with increased risk of cleft lip with or without cleft palate; meanwhile, MTHFR 1298 AC and 1298 AC/CC had protective effects against cleft lip with or without cleft palate. In further stratified analysis, we found that MTHFR 677 CT contributed to elevated risk of cleft lip only, as did MTHFR 677 CT/TT. On the contrary, MTHFR 1298 AC and 1298 AC/CC appeared to be protective against cleft lip with cleft palate. These results suggested that these two polymorphisms were involved in the development of NSOC in a southern Han Chinese population. PMID:21612398

  14. [Relationship between hyperhomocysteinemia and C677T polymorphism of methylene tetrahydrofolate reductase gene in a healthy Algerian population].

    PubMed

    Hambaba, L; Abdessemed, S; Yahia, M; Laroui, S; Rouabah, F

    2008-01-01

    Plasmatic homocysteine concentration depends mostly on 5,10 methylene tetrahydrofolate reductase (MTHFR) polymorphisms, a key enzyme in folate metabolism. The most common point mutation C677T is associated to cardiovascular and neurological pathologies; its ethnic repartition is quite heterogenic. In the present study, we proposed to describe the genotypic and allelic frequencies of C677T polymorphism and its influence on plasmatic homocysteine level in a healthy Algerian population. The investigation was turned on 100 apparently healthy voluntary subjects. Homocysteine concentration was determined using an immunoassay by fluorescence polarisation on IMx. Genotypes were determined by RT-PCR (Light cycle 480). Mean homocysteine concentration value was 14,69 +/- 7,30 micromol/L. 41% of people sample show a moderate hyperhomocysteinemia (>15 micromol/L). For the MTHFR C677T, estimated frequency of the allele T in the 100 people sample was about 35,5% with genotypic frequency of 6%. Plasmatic homocysteine is significantly higher in people carrying allele T: (CC vs CT: 11,8 +/- 2,97 micromol/L vs 15,47 +/- 6,74 micromol/L, p = 0,0004); (CC vs TT: 11,8 +/- 2,97 micromol/L vs 30,05 +/- 13,35 micromol/L, p = 0,01) and (CT vs TT: 15,47 +/- 6,74 micromol/L vs 30,05 +/- 13,35 micromol/L, p = 0,021). Our study shows an intermediate allelic frequency that joins the North-South world gradient and a high hyperhomocysteinemia prevalence. C677T polymorphism of MTHFR seems playing a predominant role in the moderate hyperhomocyteinemia. These two observations should be taken into consideration in the evaluation of morbid and/or lethal pathologies predisposition in the Algerian population. PMID:19091662

  15. Methylenetetrahydrofolate reductase deficiency alters levels of glutamate and γ-aminobutyric acid in brain tissue

    PubMed Central

    Jadavji, N.M.; Wieske, F.; Dirnagl, U.; Winter, C.

    2015-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is an enzyme key regulator in folate metabolism. Deficiencies in MTHFR result in increased levels of homocysteine, which leads to reduced levels of S-adenosylmethionine (SAM). In the brain, SAM donates methyl groups to catechol-O-methyltransferase (COMT), which is involved in neurotransmitter analysis. Using the MTHFR-deficient mouse model the purpose of this study was to investigate levels of monoamine neurotransmitters and amino acid levels in brain tissue. MTHFR deficiency affected levels of both glutamate and γ-aminobutyric acid in within the cerebellum and hippocampus. Mthfr−/− mice had reduced levels of glutamate in the amygdala and γ-aminobutyric acid in the thalamus. The excitatory mechanisms of homocysteine through activation of the N-methyl-d-aspartate receptor in brain tissue might alter levels of glutamate and γ-aminobutyric acid. PMID:26937386

  16. Meta-analysis of methylenetetrahydrofolate reductase polymorphism and lung cancer risk in Chinese

    PubMed Central

    Wang, Xin; Yue, Kai; Hao, Liran

    2015-01-01

    Numerous studies have investigated association of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism with lung cancer (LC) susceptibility in Chinese; however, the findings are inconsistent. Therefore, we performed a meta-analysis. PubMed, ISI Web of Knowledge, Chinese National Knowledge Infrastructure, and Wanfang were searched. Pooled ORs and 95% CIs were used to assess the strength of the associations. Overall, 10 studies with 2487 cases and 3228 controls investigating the MTHFR C677T polymorphism and LC risk were included. We did not find a significant association between MTHFR C677T polymorphism and LC risk. However, significantly increased LC risk was found in the population from North China, which was not found in the population from South China. In conclusion, our meta-analysis suggested that MTHFR C677T polymorphism might influence the risk of LC. PMID:25785167

  17. Methylenetetrahydrofolate reductase and methionine synthase reductase gene polymorphisms and protection from microvascular complications in adolescents with type 1 diabetes.

    PubMed

    Wiltshire, Esko J; Mohsin, Fauzia; Chan, Albert; Donaghue, Kim C

    2008-08-01

    Folate status has been associated with endothelial dysfunction in adolescents with type 1 diabetes, and elevated total plasma homoocyst(e)ine (tHcy) is a risk for vascular disease in the non-diabetic population. Polymorphisms in genes involved in folate and homocysteine metabolism are implicated in vascular disease. We aimed to determine whether polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genes are risk factors for early microvascular disease in a large group of adolescents with type 1 diabetes. Four hundred and eighty adolescents were screened annually for retinopathy and microalbuminuria for a median of 4 yr. Molecular analysis for the polymorphisms 677C-->T, 1298A-->C in MTHFR, and 66A-->G in MTRR was performed. The MTRR 66GG genotype reduced the risk for elevated albumin excretion rate (AER) (OR 0.47, CI 0.25, 0.88, p = 0.018) and showed a trend to reduced risk for microalbuminuria (OR 0.27, CI 0.06-1.21, p = 0.09). Survival without elevated AER was increased with the MTRR 66GG genotype (12.4 vs. 9.7 yr, p = 0.04) and with the MTHFR 1298CC genotype (15.2 vs. 10.2 yr, p = 0.007). Conversely, survival without retinopathy was reduced with the MTHFR 677TT and MTRR 66GG combined genotype (6.2 vs. 10.2 yr, p = 0.015). The MTRR 66GG and MTHFR 1298 CC genotypes may confer protection against early nephropathy, possibly because they are associated with lower tHcy. The MTHFR 677 TT was only related to earlier onset retinopathy in combination with MTRR 66GG. PMID:18774994

  18. Significant Impact of the MTHFR Polymorphisms and Haplotypes on Male Infertility Risk

    PubMed Central

    Gupta, Nishi; Sarkar, Saumya; David, Archana; Gangwar, Pravin Kumar; Gupta, Richa; Khanna, Gita; Sankhwar, Satya Narayan; Khanna, Anil; Rajender, Singh

    2013-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) converts 5,10-methylene tetrahydrofolate to 5-methyl tetrahydrofolate and affects the activity of cellular cycles participating in nucleotide synthesis, DNA repair, genome stability, maintenance of methyl pool, and gene regulation. Genetically compromised MTHFR activity has been suggested to affect male fertility. The objective of the present study was to find the impact on infertility risk of c.203G>A, c.1298A>C, and c.1793G>A polymorphisms in the MTHFR gene. Methods PCR-RFLP and DNA sequencing were used to genotype the common SNPs in the MTHFR gene in 630 infertile and 250 fertile males. Chi-square test was applied for statistical comparison of genotype data. Linkage disequilibrium between the SNPs and the frequency of common haplotypes were assessed using Haploview software. Biochemical levels of total homocysteine (tHcy) and folic acid were measured. Meta-analysis on c.1298A>C polymorphism was performed using data from ten studies, comprising 2734 cases and 2737 controls. Results c.203G>A and c.1298A>C were found to be unrelated to infertility risk. c.1793G>A was protective against infertility (P = 0.0008). c.677C>T and c.1793G>A were in significant LD (D’ = 0.9). Folic acid and tHcy level did not correlate with male infertility. Pooled estimate on c.1298A>C data from all published studies including our data showed no association of this polymorphism with male infertility (Odds ratio = 1.035, P = 0.56), azoospermia (Odds ratio = 0.97, P = 0.74), or oligoasthenoteratozoospermia (Odds ratio = 0.92, p = 0.29). Eight haplotypes with more than 1% frequency were detected, of which CCGA was protective against infertility (p = 0.02), but the significance of the latter was not seen after applying Bonferroni correction. Conclusion Among MTHFR polymorphisms, c.203G>A and c.1298A>C do not affect infertility risk and c.1793G>A is protective against infertility. Haplotype analysis

  19. Correlation between C677T MTHFR gene polymorphism, plasma homocysteine levels and the incidence of CAD.

    PubMed

    Nakai, K; Itoh, C; Nakai, K; Habano, W; Gurwitz, D

    2001-01-01

    The lesions of coronary atherosclerosis represent the result of a complex, multicellular, inflammatory-healing response in the coronary arterial wall. In vivo and in vitro cellular and molecular studies have suggested a role for tissue homocysteine in endothelial cell injury and adverse extra-cellular matrix remodeling. Gene polymorphisms in relation with numerous risk factors might increase the incidence of coronary artery disease (CAD). In this review we have focused on the correlations between plasma homocysteine levels, the incidence of cardiovascular disease and the cytosine-to-thymidine substitution at nucleotide 677 (C677T) of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, coding for a key enzyme in methionine-homocysteine metabolism. The role of the C677T MTHFR gene polymorphism in the causation of CAD is controversial. We reviewed 12 recent case-control studies comprising 5370 genotyped patients with CAD and 4961 genotyped participants without CAD. There was no significant difference between those with and without CAD in the frequency of the C677T polymorphism (34.9 vs 33.6%). The frequency of homozygous C677T polymorphism in these groups was 10.9 versus 12.8%, respectively, although there were some ethnic differences in the C677T MTHFR polymorphism. In the analysis of the 12 studies, the odds ratio of CAD associated with the TT genotype (homozygous C677T polymorphism) was 1.18. Only slightly higher plasma homocysteine levels were observed in participants with the val/val (TT) genotype (14.4+/-2.9 micro mol/L in TT genotype vs 11.1+/-1.9 and 11.9+/-2 micro mol/L in CC and CT genotype, respectively). In addition, the relation between homocysteine increase after methionine loading and MTHFR genotypes is also controversial. However, hyperhomocysteinemia because of the C677T MTHFR allele may be corrected with oral folic acid therapy. Further investigations on the relationships between MTHFR genotypes and the incidence of CAD should be based on

  20. Contribution of GSTM1, GSTT1, and MTHFR polymorphisms to end-stage renal disease of unknown etiology in Mexicans

    PubMed Central

    Gutiérrez-Amavizca, B. E.; Orozco-Castellanos, R.; Ortíz-Orozco, R.; Padilla-Gutiérrez, J.; Valle, Y.; Gutiérrez-Gutiérrez, N.; García-García, G.; Gallegos-Arreola, M.; Figuera, L. E.

    2013-01-01

    Oxidative stress is increased in chronic kidney disease, owing to an imbalance between the oxidative and antioxidant pathways as well as a state of persistent hyperhomocysteinemia. The enzymes glutathione S-transferases (GSTs) and methylenetetrahydrofolate reductase (MTHFR) are implicated in the regulation of these pathways. This study investigates the association between polymorphisms in the Glutathione S-transferase Mu 1 (GSTM1), glutathione S-transferase theta 1 (GSTT1), and MTHFR genes and end-stage renal disease (ESRD) of unknown etiology in patients in Mexico. A Case-control study included 110 ESRD patients and 125 healthy individuals. GSTM1 and GSTT1 genotypes were determined using the multiplex polymerase chain reaction (PCR). The MTHFR C677T polymorphism was studied using a PCR/restriction fragment length polymorphism method. In ESRD patients, GSTM1 and GSTT1 null genotype frequencies were 61% and 7% respectively. GSTM1 genotype frequencies differed significantly between groups, showing that homozygous deletion of the GSTM1 gene was associated with susceptibility to ESRD of unknown etiology (P = 0.007, odds ratios = 2.05, 95% confidence interval 1.21-3.45). The MTHFR C677T polymorphism genotype and allele distributions were similar in both groups (P > 0.05), and the CT genotype was the most common genotype in both groups (45.5% and 46.6%). Our findings suggest that the GSTM1 null polymorphism appears to be associated with the ESRD of unknown etiology in patients in Mexico. PMID:24339523

  1. Spectrum of MTHFR gene SNPs C677T and A1298C: a study among 23 population groups of India.

    PubMed

    Saraswathy, Kallur Nava; Asghar, Mohammad; Samtani, Ratika; Murry, Benrithung; Mondal, Prakash Ranjan; Ghosh, Pradeep Kumar; Sachdeva, Mohinder Pal

    2012-04-01

    Elevated homocysteine is a risk factor for many complex disorders. The role of methylenetetrahydrofolate reductase (MTHFR) gene in methylation of homocysteine makes it one of the most important candidate genes for these disorders. Considering the heterogeneity in its distribution in world populations, we screened MTHFR C677T and A1298C single nucleotide polymorphisms in a total of 23 Indian caste, tribal and religious population groups from five geographical regions of India and belonging to four major linguistic groups. The frequencies of MTHFR 677T and 1298C alleles were found to be 10.08 and 20.66%, respectively. MTHFR homozygous genotype 677TT was absent in eight population groups and homozygous 1298CC was absent in two population groups. 677T allele was found to be highest among north Indian populations with Indo-European tongue and 1298C was high among Dravidian-speaking tribes of east India and south India. The less common mutant haplotype 677T-1298C was observed among seven population groups and overall the frequency of this haplotype was 0.008, which is similar to that of African populations. cis configuration of 677T and 1298C was 0.94%. However, we could not find any individual with four mutant alleles which supports the earlier observation that presence of more than two mutant alleles may decrease the viability of foetus and possibly be a selective disadvantage in the population. PMID:22147263

  2. Quantification of gene-specific methylation of DNMT3B and MTHFR using sequenom EpiTYPER®.

    PubMed

    Ho, Vikki; Ashbury, Janet E; Taylor, Sherryl; Vanner, Stephen; King, Will D

    2016-03-01

    Among 272 patients undergoing a screening colonoscopy, DNA methylation of DNMT3B and MTHFR, genes encoding enzymes critical to one-carbon metabolism, was quantified in blood leukocytes using Sequenom EpiTYPER®. DNA methylation was quantified in 66 and 28 CpG sites of DNMT3B and MTHFR respectively, and conceptualized using two approaches. First, measures representing average methylation across all CpG sites were created. Second, unsupervised principal component (PC) analysis was used as a pattern derivation and data-reduction approach, to develop two summary variables (PC1 and PC2). These two summary variables represented methylation around the transcription start site (PC1) and in the gene-coding area (PC2) for both DNMT3B and MTHFR. The data contained in this article presents the variation of methylation levels for individual CpG sites within the DNMT3B and MTHFR genes and possible correlations uncovered using PC analysis. The data are related to the research article "Gene-specific DNA methylation of DNMT3B and MTHFR and colorectal adenoma risk" in Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis. PMID:26759827

  3. The MTHFR C677T Polymorphism and Risk of Intracerebral Hemorrhage in a Chinese Han Population

    PubMed Central

    Hu, Xin; Tao, Chuanyuan; Xie, Zhiyi; Li, Yunke; Zheng, Jun; Fang, Yuan; Lin, Sen; Li, Hao; You, Chao

    2016-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism has been speculated to be and extensively investigated as a risk factor for various vascular diseases, including intracerebral hemorrhage (ICH). However, results from published studies regarding the role of C677T polymorphism in ICH risk in Chinese populations were contradictory rather than conclusive. Material/Methods In this study, a total of 180 ICH patients and 180 matched controls of Chinese Han ethnicity were enrolled. The MTHFR C677T polymorphism was genotyped by polymerase chain reaction-ligation detection reaction (PCR-LDR). A meta-analysis was conducted by combining our data with previous relevant studies in Chinese populations. Results In our case-control study, similar allele frequency (p=0.492) and genotype distribution (p=0.748) of MTHFR C677T polymorphism were detected between ICH patients and controls. Further analysis based on hematoma location did not show a significant association. When combined with previous studies, however, C677T polymorphism was found to be significantly associated with an increased risk for ICH in Chinese populations (recessive model: OR=1.57, 95%CI=1.29–1.91). When focusing on the Han ethnicity, carriers of the TT genotype had an increased risk of ICH (recessive model: OR=1.36, 95%CI=1.05–1.75). Conclusions In this case-control study we did not observe that the MTHFR C677T polymorphism was associated with ICH risk in people of Chinese Han ethnicity. However, when combined with previous published studies, a significant association of C677T polymorphism with an increased risk of ICH was detected in Chinese populations, and also in the subgroup analysis focusing on Han ethnicity. PMID:26757363

  4. Meta-analysis of the association of MTHFR polymorphisms with multiple myeloma risk.

    PubMed

    Ma, Li-Min; Ruan, Lin-Hai; Yang, Hai-Ping

    2015-01-01

    The association of methylenetetrahydrofolate reductase (MTHFR) polymorphisms with multiple myeloma (MM) risk has been explored, but the results remain controversial. Thus, a meta-analysis was performed to provide a comprehensively estimate. The case-control studies about MTHFR C677T and A1298C polymorphisms with MM risk were collected by searching PubMed, Elsevier, China National Knowledge Infrastructure and Wanfang Databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to assess the strength of association. Overall, no significant association was found between MTHFR A1298C polymorphism and MM risk under all four genetic models (AC vs. AA, OR = 0.99, 95%CI = 0.82-1.20; CC vs. AA, OR = 1.14, 95%CI = 0.77-1.68; recessive model, OR = 1.10, 95%CI = 0.76-1.59; dominant model, OR = 1.01, 95%CI = 0.84-1.22). The risk was also not significantly altered for C677T polymorphism and MM in overall comparisons (CT vs. CC, OR = 1.04, 95%CI = 0.93-1.17; TT vs. CC, OR = 1.16, 95%CI = 0.98-1.37; recessive model, OR = 1.13, 95%CI = 0.98-1.32; dominant model, OR = 1.07, 95%CI = 0.96-1.20). In subgroup analyses by ethnicity, no significant association was observed in both Caucasians and Asians. This meta-analysis suggested that MTHFR polymorphisms were not associated with MM risk. PMID:26022785

  5. Meta-analysis of the association of MTHFR polymorphisms with multiple myeloma risk

    PubMed Central

    Ma, Li-Min; Ruan, Lin-Hai; Yang, Hai-Ping

    2015-01-01

    The association of methylenetetrahydrofolate reductase (MTHFR) polymorphisms with multiple myeloma (MM) risk has been explored, but the results remain controversial. Thus, a meta-analysis was performed to provide a comprehensively estimate. The case-control studies about MTHFR C677T and A1298C polymorphisms with MM risk were collected by searching PubMed, Elsevier, China National Knowledge Infrastructure and Wanfang Databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to assess the strength of association. Overall, no significant association was found between MTHFR A1298C polymorphism and MM risk under all four genetic models (AC vs. AA, OR = 0.99, 95%CI = 0.82-1.20; CC vs. AA, OR = 1.14, 95%CI = 0.77-1.68; recessive model, OR = 1.10, 95%CI = 0.76-1.59; dominant model, OR = 1.01, 95%CI = 0.84-1.22). The risk was also not significantly altered for C677T polymorphism and MM in overall comparisons (CT vs. CC, OR = 1.04, 95%CI = 0.93-1.17; TT vs. CC, OR = 1.16, 95%CI = 0.98-1.37; recessive model, OR = 1.13, 95%CI = 0.98-1.32; dominant model, OR = 1.07, 95%CI = 0.96-1.20). In subgroup analyses by ethnicity, no significant association was observed in both Caucasians and Asians. This meta-analysis suggested that MTHFR polymorphisms were not associated with MM risk. PMID:26022785

  6. Homocysteine levels are associated with MTHFR A1298C polymorphism in Indian population.

    PubMed

    Kumar, Jitender; Das, Swapan K; Sharma, Priyanka; Karthikeyan, Ganesan; Ramakrishnan, Lakshmy; Sengupta, Shantanu

    2005-01-01

    An elevated level of homocysteine is an independent risk factor for cardiovascular diseases and is associated with other complex disorders. Homocysteine levels can be elevated due to dietary and/or genetic factors. A majority of Indian population have a low level of vitamin B12 (presumably due to vegetarian diet)--a critical nutritional factor, deficiency of which results in hyperhomocysteinemia. Hence, polymorphisms in the genes responsible for homocysteine metabolism can be perceived to have a greater impact in relation to hyperhomocysteinemia in Indian population. For this reason, the effects of diet and/or methylenetetrahydrofolate reductase (MTHFR) polymorphism were assessed in 200 individuals having varying homocysteine levels. Homocysteine levels were significantly elevated in individuals adhering to a vegetarian diet (P = 0.019) or having MTHFR A1298C polymorphism (P = 0.006). The minor allele frequency (MAF) of MTHFR C677T and A1298C was 0.15 and 0.44 respectively in this cohort. Since the MAF of these polymorphisms differed considerably from Caucasian and other Asian populations, frequencies of these polymorphisms were also determined in more than 400 individuals from different ethnic populations, selected from the entire country based on their geographical location and linguistic lineage, and was found to be similar to that of our cohort. The fact that MTHFR A1298C polymorphism is significantly associated with homocysteine levels, and that the CC genotype is present at a higher frequency in the Indian population, makes it extremely relevant in terms of its potential impact on hyperhomocysteinemia. PMID:16244782

  7. MTHFR Polymorphisms, Folate Intake, and Carcinogen DNA Adducts in the Lung

    PubMed Central

    Lee, Mi-Sun; Asomaning, Kofi; Su, Li; Wain, John C.; Mark, Eugene J.; Christiani, David C.

    2011-01-01

    The methylenetetrahydrofolate reductase (MTHFR) genes and folate in one-carbon metabolism are essential for DNA methylation and synthesis. However, their role in carcinogen DNA damage in target lung tissue, a dosimeter for cancer risk, is not known. Our study aimed to investigate the association between genetic and nutritional one-carbon metabolism factors and DNA adducts in target lung. Data on 135 lung cancer cases from the Massachusetts General Hospital were studied. Genotyping was completed for MTHFR C677T (rs1801133) and A1298C (rs1801131). Information on dietary intake for one-carbon related micronutrients, folate and other B vitamin, was derived from a validated food frequency questionnaire. DNA adducts in lung were measured by 32P-postlabeling. After adjusting for potential confounders, DNA adduct levels in lung significantly increased by 69.2% [95% confidence interval (CI), 5.5% to 171.5%] for the MTHFR 1298AC+CC genotype. The high risk group, combining the A1298C (AC+CC) plus C677T (CT+TT) genotypes, had significantly enhanced levels of lung adducts by 210.7% (95% CI, 21.4% to 695.2%) in contrast to the A1298C (AA) plus C677T (CC) genotypes. Elevation of DNA adduct was pronounced - 111.3% (95% CI, −3.0 to 360.5%) among 1298AC+CC patients who consumed the lowest level of folate intake as compared with 1298AA individuals with highest tertile of intake. These results indicate that DNA adducts levels are influenced by MTHFR polymorphisms and low folate consumption, suggesting an important role of genetic and nutritional factors in protecting DNA damage from lung carcinogen in at-risk populations. PMID:22052259

  8. The Evaluation of Serum Copeptin Levels and Some Commonly Seen Thrombophilic Mutation Prevalence in Acute Pulmonary Embolism.

    PubMed

    Ozturk, Nurinnisa; Baygutalp, Nurcan Kilic; Bayramoglu, Atif; Polat, Harun; Gul, Mehmet Ali; Bakan, Ebubekir; Aslan, Sahin; Gunes, Ozge Nur

    2016-06-01

    Acute pulmonary embolism (PE) is a common, emergent condition and may affect a large number of patients. Copeptin has been indicated to be a sensitive biomarker of arginine vasopressin release, and has diagnostic and prognostic value in various clinical conditions. Genetic mutations are considerable components of thrombophilic diseases, and factor II gene G20210A, (FII20210A), factor V Leiden (FVL, G1691A) and methylenetetrahydrofolate reductase gene C677T (MTHFR677T) single nucleotide polymorphisms are the most common mutations of thrombophilic diseases. In this study, serum copeptin levels were determined in patients with PE and healthy controls, and the results were discussed. The prevalence of some commonly seen thrombophilic mutations was also evaluated in patients with PE. The study included 32 patients (18 male, 14 female) with PE and 24 (13 male, 11 female) age- and gender-matched healthy controls. A significant difference in serum copeptin levels was determined between the patient and control groups (8.58 ± 4.42 and 4.07 ± 1.02 pmol/L, respectively). Heterozygous mutant genotype for FII20210A and heterozygous mutant genotype for FVL were observed in 3.1 and 9.4% of patients, respectively. Mutant genotype of 49% was determined for MTHFR677T mutations. It was concluded that copeptin may have diagnostic value for PE. PMID:26886096

  9. Molecular analysis of the SRD5A2 in 46,XY subjects with incomplete virilization: the P212R substitution of the steroid 5alpha-reductase 2 may constitute an ancestral founder mutation in Mexican patients.

    PubMed

    Vilchis, Felipe; Ramos, Luis; Méndez, Juan Pablo; Benavides, Socorro; Canto, Patricia; Chávez, Bertha

    2010-01-01

    Inactivating mutations of the SRD5A2 gene result in steroid 5α-reductase 2 deficiency, an autosomal recessive disorder expressed as a male-limited disorder of sex development. Herein, genomic DNA was isolated from 11 new patients with apparent steroid 5α-reductase 2 deficiency. Coding sequence abnormalities in SRD5A2 were assessed by exon-specific polymerase chain reaction, single-stranded conformation polymorphism, and direct sequencing. Likewise, enzymatic activity of the P212R gene variant of SRD5A2 was assessed. DNA analysis revealed mutations in all patients (G115D, R171S, N193S, E197D, G203S, P212R). Three individuals were compound heterozygotes, 6 were homozygotes, and 2 more were single heterozygotes for SRD5A2 mutations; remarkably, 40% of the mutant alleles (9/22) contained the gene variant P212R. The results described in this study represent, along with our previous reports, the largest number of patients with steroid 5α-reductase 2 deficiency belonging to nonrelated families. Regarding the frequency of the p.P212R mutation in our population and its presence throughout all of our country, it allows us to hypothesize that the presence of this mutation may constitute a founder gene effect. PMID:20019388

  10. MTHFR deficiency or reduced intake of folate or choline in pregnant mice results in impaired short-term memory and increased apoptosis in the hippocampus of wild-type offspring.

    PubMed

    Jadavji, N M; Deng, L; Malysheva, O; Caudill, M A; Rozen, R

    2015-08-01

    Genetic or nutritional disturbances in one-carbon metabolism, with associated hyperhomocysteinemia, can result in complex disorders including pregnancy complications and neuropsychiatric diseases. In earlier work, we showed that mice with a complete deficiency of methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in folate and homocysteine metabolism, had cognitive impairment with disturbances in choline metabolism. Maternal demands for folate and choline are increased during pregnancy and deficiencies of these nutrients result in several negative outcomes including increased resorption and delayed development. The goal of this study was to investigate the behavioral and neurobiological impact of a maternal genetic deficiency in MTHFR or maternal nutritional deficiency of folate or choline during pregnancy on 3-week-old Mthfr(+/+) offspring. Mthfr(+/+) and Mthfr(+/-) females were placed on control diets (CD); and Mthfr(+/+) females were placed on folate-deficient diets (FD) or choline-deficient diets (ChDD) throughout pregnancy and lactation until their offspring were 3weeks of age. Short-term memory was assessed in offspring, and hippocampal tissue was evaluated for morphological changes, apoptosis, proliferation and choline metabolism. Maternal MTHFR deficiency resulted in short-term memory impairment in offspring. These dams had elevated levels of plasma homocysteine when compared with wild-type dams. There were no differences in plasma homocysteine in offspring. Increased apoptosis and proliferation was observed in the hippocampus of offspring from Mthfr(+/-) mothers. In the maternal FD and ChDD study, offspring also showed short-term memory impairment with increased apoptosis in the hippocampus; increased neurogenesis was observed in ChDD offspring. Choline acetyltransferase protein was increased in the offspring hippocampus of both dietary groups and betaine was decreased in the hippocampus of FD offspring. Our results reveal short-term memory

  11. Association between MTHFR C677T and A1298C Polymorphisms and NSCL/P Risk in Asians: A Meta-Analysis

    PubMed Central

    Zhao, Mengmeng; Ren, Yangwu; Shen, Li; Zhang, Yue; Zhou, Baosen

    2014-01-01

    Objective Several studies have reported the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and nonsyndromic cleft lip with or without palate (NSCL/P) in Asian populations. However, findings have been conflicting. In order to investigate the association, a meta-analysis was performed. Methods We searched Pubmed, MedLine and EmBase database to selected eligible studies. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated using fixed effects model or random effects model to assess the association between MTHFR polymorphisms and NSCL/P in both Asian children and mothers. Results Finally, nine case-control studies were included. Overall, the MTHFR C677T polymorphism and NSCL/P showed pooled ORs (95%CI) of 1.41(1.23–1.61) in Asian children, and 1.70(1.19–2.42) in Asian mothers. Subgroup analyses by geographical locations further identified the association in Eastern Asian children, Western/Central Asian children and mothers, but not in Eastern Asian mothers. However, no significant relationship between MTHFR A1298C polymorphism and NSCL/P was found in this meta-analysis. Conclusions The MTHFR 677T allele was associated with an increased risk of NSCL/P in Asian populations. PMID:24658649

  12. A novel L218P mutation in NADH-cytochrome b5 reductase associated with type I recessive congenital methemoglobinemia.

    PubMed

    Arikoglu, Tugba; Yarali, Nese; Kara, Abdurrahman; Bay, Ali; Bozkaya, Ikbal O; Tunc, Bahattin; Percy, Melanie J

    2009-01-01

    The presence of central cyanosis that is unrelated to cardiopulmonary causes alerts clinicians to a possible diagnosis of methemoglobinemia. Congenital methemoglobinemia due to deficiency of nicotinamide-adenine dinucleotide (NADH)-cytochrome b5 reductase (cb(5)r) is an autosomal recessive disorder characterized by life long cyanosis. Here we report a six-year old boy who presented with central cyanosis and upon examination revealed a methemoglobin level of 19.0%. Sequencing the CYB5R3 gene identified a homozygous T-->C transition at base c.653, which changed codon 218 from leucine to proline (L218P) in cb(5)r protein. Treatment with ascorbic acid relieved the cyanosis and returned methemoglobin levels to normal. PMID:19579085

  13. Methyltetrahydrofolate reductase polymorphism influences onset of Huntington's disease.

    PubMed

    Brune, N; Andrich, J; Gencik, M; Saft, C; Müller, Th; Valentin, S; Przuntek, H; Epplen, J T

    2004-01-01

    Onset of Huntington's disease (HD) negatively correlates with CAG repeat length of the HD gene, which encodes the protein huntingtin. This protein interacts with the homocysteine metabolizing enzyme cystathionine betasynthase (CBS). Objective of this study was to analyze the impact of CAG repeats, polymorphisms of various homocysteine metabolizing enzymes, like CBS, Methyltetrahydrofolate Reductase (MTHTR), Methionine Synthase Reductase (MSR) and methionine synthase (MS) on HD onset in 171 patients. The significant impact of CAG repeats on HD onset (chi2= 25.54, FG = 4, p<0.0001) with a significant correlation between both (R= -0.521, p=0.01) was obvious. HD patients with the homozygous MTHFR-1298-CC significantly (p = 0.024) earlier experienced HD symptoms. There was no influence demonstrable of CBS, MSR and MS. Determination of MTHFR polymorphisms and CAG repeats enables screening for subjects with putative early HD onset in order to study neuroprotective compounds in their efficacy to delay HD symptoms. PMID:15354395

  14. Contraception-related deep venous thrombosis and pulmonary embolism in a 17-Year-old girl heterozygous for factor V leiden, prothrombin G20210A mutation, MTHFR C677T and homozygous for PAI-1 mutation: report of a family with multiple genetic risk factors and review of the literature.

    PubMed

    Lenicek Krleza, Jasna; Jakovljevic, Gordana; Bronic, Ana; Coen Herak, Désirée; Bonevski, Aleksandra; Stepan-Giljevic, Jasminka; Roic, Goran

    2010-01-01

    We present the case of a 17-year-old girl who suddenly woke up with localized pain in the left groin and the inability to twist her leg. After comprehensive physician and laboratory examinations, deep venous thrombosis with consequent pulmonary embolism was ascertained. She had not experienced any recent trauma, but she had started to take oral contraceptives 6 months prior to the onset of the symptoms. Her parents and sisters had been asymptomatic throughout their lives, but the family history revealed a few thromboembolic accidents. Using DNA analysis, heterozygosity for factor V Leiden, prothrombin gene mutation G20210A and methylenetetrahydrofolate reductase C677T, as well as the homozygous 4G/4G genotype in the plasminogen activator inhibitor 1 were identified in our patient. Subsequently, DNA analysis was performed in all living family members, and multiple factors associated with thrombophilia were discovered. Our case confirms the multifactorial cause of thromboembolic events and emphasizes the importance of oral contraceptive use in the onset of venous thrombosis, especially in teenage females. In addition, this case indicates that teenage females with a family history of thrombosis who are making choices about contraception could most likely benefit from advanced thrombophilia testing. PMID:20664190

  15. Identification of three new mutations in the NADH-cytochrome b5 reductase gene responsible for recessive congenital methemoglobinemia type II

    SciTech Connect

    Mota-Vieira, L.; Kaplan, J.C.; Kahn, A.; Leroux, A.

    1994-09-01

    Recessive congenital methemoglobinemia (RCM; McKusick N{degrees}25800) due to NADH-cytochrome b5 reductase (cytb5r) deficiency leads to two different types of diseases: in type I form, cyanosis is the only symptom and the enzyme is only defective in red blood cells; in type II form, cyanosis is associated with severe mental retardation and neurological impairment and the enzyme defect is systemic. We have identified three new molecular defects in two unrelated patients with type II RCM. A homozygous C{r_arrow}T transition in codon 218 (Arg) was detected in the cDNA of one patient, resulting in a premature stop codon (TGA) in exon 8. Restriction enzyme analysis of genomic DNA confirmed the homozygosity of the propositus and heterozygosity for an identical defect in both parents. The second patient was found to be a compound heterozygote, carrying two different mutant alleles in the cyb5r gene. One allele presented a missense mutation (T{r_arrow}C) with substitution of Cys-203 (TGC) by Arg (CGC) in exon 7. The second allele showed a 3 bp deletion of nucleotides 815-817 of the cDNA. The CTG ATG sequence at position 814-819 in exon 9 coding for Leu-271 and Met-272 was replaced by the CTG triplet, with conservation of the Leu-271 and loss of the Met-272. To our knowledge, these are the first examples of a homozygous nonsense mutation and of a compound heterozygous mutation detected in the cytb5r gene. This finding supports the diversity of genetic defects in the cytb5r gene leading to the severe form of the disease.

  16. MTHFR C677T and A1298C polymorphisms and risk of lung cancer: a comprehensive evaluation.

    PubMed

    Yang, Y; Yang, L J; Deng, M Z; Luo, Y Y; Wu, S; Xiong, L; Wang, D; Liu, Y; Liu, H

    2016-01-01

    Results from previous studies on the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms C677T and A1298C and lung cancer have been conflicting. The aim of this meta-analysis was to clarify the effect of MTHFR polymorphisms on the risk of lung cancer. An electronic search of PubMed, EMBASE, the Cochrane library, and the China Knowledge Resource Integrated Database for papers on C677T and A1298C and susceptibility to lung cancer was performed. The STATA software (Version 13.0) was used for statistical analysis. Statistical heterogeneity, tests of publication bias, and a sensitivity analysis were performed. Twenty-six studies on C677T (12,324 cases and 12,532 controls) and thirteen studies on A1298C (6773 cases and 8207 controls) were included in the meta-analysis. The MTHFR C677T polymorphism showed significant pooled ORs for the homozygote comparison (TT versus CC: OR = 1.518, 95%CI = 1.220-1.890), heterozygote comparison (CT versus CC: OR = 1.053, 95%CI = 0.940-1.179), dominant model (CT + TT versus CC: OR = 1.143, 95%CI = 1.013-1.291), recessive model (TT versus CT + CC: OR = 1.435, 95%CI = 1.190-1.730), and additive model (T versus C: OR = 1.176, 95%CI = 1.066-1.298). In summary, our meta-analysis showed that the MTHFR C677T polymorphism is associated with a significant increase in lung cancer risk in Asian and overall populations, but not in Caucasian populations. However, no significant association between the MTHFR A1298C polymorphism and lung cancer risk was found in either the Caucasian or Asian group with any genetic models. PMID:27173216

  17. MTHFR C677T Polymorphism is Associated with Tumor Response to Preoperative Chemoradiotherapy: A Result Based on Previous Reports

    PubMed Central

    Zhao, Yue; Li, Xingde; Kong, Xiangjun

    2015-01-01

    Background Preoperative chemoradiotherapy (pRCT) followed by surgery has been widely practiced in locally advanced rectal cancer, esophageal cancer, gastric cancer and other cancers. However, the therapy also exerts some severe adverse effects and some of the patients show poor or no response. It is very important to develop biomarkers (e.g., gene polymorphisms) to identify patients who have a higher likelihood of responding to pRCT. Recently, a series of reports have investigated the association of the genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and epidermal growth factor receptor (EGFR) genes with the tumor response to pRCT; however, the results were inconsistent and inconclusive. Material/Methods A systematic review and meta-analysis was performed by searching relevant studies about the association of MTHFR and EGFR polymorphisms with the tumor regression grade (TRG) in response to pRCT in databases of PubMed, EMBAS, Web of science, Chinese National Knowledge Infrastructure, and Wanfang database up to March 30, 2015. The pooled odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs) were calculated to assess the strength of the association under 5 genetic models. Results A total of 11 eligible articles were included in the present meta-analysis, of which 8 studies were performed in rectal cancer and 3 studies were performed in esophageal cancer. We finally included 8 included studies containing 839 cases for MTHFR C677T, 5 studies involving 634 cases for MTHFR A1298C, 3 studies containing 340 cases for EGFR G497A, and 4 studies containing 396 cases for EGFR CA repeat. The pooled analysis results indicated that MTHFR C677T might be correlated with the tumor response to pRCT under the recessive model (CC vs. CTTT) in overall analysis (OR=1.426(1.074–1.894), P=0.014), rectal cancer (OR=1.483(1.102–1.996), P=0.009), and TRG 1–2 vs. 3–5 group (OR=1.423(1.046–1.936), P=0.025), while other polymorphism including MTHFR

  18. Methylenetetrahydrofolate reductase gene polymorphisms in Burkina Faso: impact on plasma fasting homocysteine and after methionine loading test.

    PubMed

    Angius, Andrea; Simpore, Jacques; Persico, Ivana; Sassu, Alessandro; Prodi, Dionigio Antonio; Musumeci, Salvatore

    2007-01-01

    In Burkina Faso the levels of plasma homocysteine (Hcy) are lower and the methionine loading tests suggest a more effective Hcy metabolism. The polymorphisms of methylenetetrahydrofolate reductase (MTHFR) showed a relevant difference in the allele frequencies of T MTHFR-677 in young and in old subjects, while the allele frequency of C MTHFR-1298 was comparable in young and old subjects. The aim of this paper was to study the impact of the MTHFR polymorphisms on plasma fasting Hcy and after methionine loading in Burkina Faso. The young subjects with CC MTHFR-677 genotype had levels of Hcy significantly lower than CT and TT subjects. The level of Hcy in subjects who had AA, AC and CC MTHFR-1298 genotypes were comparable. The levels of Hcy after the methionine loading test were significantly higher in CT and TT MTHFR-677 genotype. These results suggest that the genetic situation in Burkina Faso is different from that of other Western countries and this guarantees the maintenance of lower plasma levels of Hcy in young and old Africans. The elevated levels of plasma Hcy in old subjects compared to young subjects, against the low prevalence of the T allele in elderly subjects, is discussed. PMID:17323822

  19. Association between methylenetetrahydrofolate reductase C677T polymorphism and psoriasis: A meta-analysis.

    PubMed

    Wu, Dongze; Shi, Deshun; Yang, Li; Zhu, Xiaoliang

    2016-02-01

    Several studies have evaluated the associations between methylenetetrahydrofolate reductase (MTHFR) C677T and psoriasis. However, the results remain inconclusive. The objective of the present study was to conduct a qualitative and quantitative meta-analysis investigating the associations between MTHFR C677T and psoriasis. A published work search of PubMed, Embase, Web of Science and Chinese National Knowledge Infrastructure database were conducted to identify all publications concerning MTHFR C677T polymorphism and psoriasis on 1 October 2014. The principal outcome measure for evaluating the strength of the association was crude odds ratios along with their corresponding 95% confidence intervals. Data were extracted and statistical analyses were implemented using STATA version 12.0 software. A total of 1179 psoriatic cases and 937 controls from five case-control studies concentrating on the association between MTHFR C677T polymorphism and psoriasis were included in this qualitative meta-analysis. Pooled analysis revealed that there is no association between this polymorphism and susceptibility to psoriasis in dominant, recessive, allele and additive models under a random-effect model. However, a marginal significant association was found in the overdominant model under fixed-effect model. Subgroup analysis of ethnicity demonstrated that there is no association between MTHFR C677T polymorphism and either Asian or European psoriatic patients. In conclusion, MTHFR C677T polymorphism, qualitatively, is not a genetic factor for the pathogenesis of psoriasis but could quantitatively reflect the severity of psoriasis to some extent. PMID:26212228

  20. The impact of C677T and A1298C MTHFR polymorphisms on methotrexate therapeutic response in East Bohemian region rheumatoid arthritis patients.

    PubMed

    Soukup, Tomas; Dosedel, Martin; Pavek, Petr; Nekvindova, Jana; Barvik, Ivan; Bubancova, Iva; Bradna, Petr; Kubena, Ales Antonin; Carazo, Alejandro Fernández; Veleta, Tomas; Vlcek, Jiri

    2015-07-01

    Some single-nucleotide polymorphisms (SNPs) might be predictive of methotrexate (MTX) therapeutic outcome in rheumatoid arthritis (RA). The aim of this study was to determine whether SNPs in the methylenetetrahydrofolate reductase (MTHFR) gene are predictive of MTX response. Comparison was made using EULAR response criteria and according to the change of DAS28 (∆DAS28) after a 6-month MTX treatment in RA patient cohort. The two SNPs C677T (rs1801133) and A1298C (rs1801131) have been genotyped. A total of 120 patients were enrolled in the study, and all of them fulfilled the American College of Rheumatology 1987 RA criteria and are currently or previously taking MTX oral treatment, either as a monotherapy (n = 65) or in a combination with other disease-modifying antirheumatic drugs (n = 55). Genotyping was performed using qPCR allelic discrimination. We did not found any association of C677T and A1298C genotypes with MTX treatment inefficacy in dominant model (OR 1.23, 95 % CI 0.57-2.65, P = 0.697; and OR 0.98, 95 % CI 0.47-2.14, P = 1.0, respectively), or in recessive and codominant models. However, when ∆DAS28 after a 6-month therapy was used as a measure of treatment efficacy, the 677CT and 1298AC genotypes were found to be significantly associated with less favorable response to MTX (P = 0.025 and P = 0.043, respectively). In addition, even lower ∆DAS28 was determined for double-mutated 677CT-1298AC heterozygotes. It means that a synergistic effect of 677CT and 1298AC genotypes was observed. Nevertheless, the DAS28 baseline was lower here comparing to other genotypes. Unexpectedly, quite the opposite trend-i.e., better response to MTX-was found in genotypes 677CC-1298CC and 677TT-1298AA. It is an intriguing finding, because these double-mutated homozygotes are known for their low MTHFR-specific activity. Global significance was P = 0.013, η (2) = 0.160-i.e., large-size effect. Thus, our data show greater ability of 677CC-1298CC and 677TT

  1. A mutated xylose reductase increases bioethanol production more than a glucose/xylose facilitator in simultaneous fermentation and co-fermentation of wheat straw

    PubMed Central

    2011-01-01

    Genetically engineered Saccharomyces cerevisiae strains are able to ferment xylose present in lignocellulosic biomass. However, better xylose fermenting strains are required to reach complete xylose uptake in simultaneous saccharification and co-fermentation (SSCF) of lignocellulosic hydrolyzates. In the current study, haploid Saccharomyces cerevisiae strains expressing a heterologous xylose pathway including either the native xylose reductase (XR) from P. stipitis, a mutated variant of XR (mXR) with altered co-factor preference, a glucose/xylose facilitator (Gxf1) from Candida intermedia or both mXR and Gxf1 were assessed in SSCF of acid-pretreated non-detoxified wheat straw. The xylose conversion in SSCF was doubled with the S. cerevisiae strain expressing mXR compared to the isogenic strain expressing the native XR, converting 76% and 38%, respectively. The xylitol yield was less than half using mXR in comparison with the native variant. As a result of this, the ethanol yield increased from 0.33 to 0.39 g g-1 when the native XR was replaced by mXR. In contrast, the expression of Gxf1 only slightly increased the xylose uptake, and did not increase the ethanol production. The results suggest that ethanolic xylose fermentation under SSCF conditions is controlled primarily by the XR activity and to a much lesser extent by xylose transport. PMID:21906329

  2. Enhancement of the Chaperone Activity of Alkyl Hydroperoxide Reductase C from Pseudomonas aeruginosa PAO1 Resulting from a Point-Specific Mutation Confers Heat Tolerance in Escherichia coli.

    PubMed

    Lee, Jae Taek; Lee, Seung Sik; Mondal, Suvendu; Tripathi, Bhumi Nath; Kim, Siu; Lee, Keun Woo; Hong, Sung Hyun; Bai, Hyoung-Woo; Cho, Jae-Young; Chung, Byung Yeoup

    2016-08-31

    Alkyl hydroperoxide reductase subunit C from Pseudomonas aeruginosa PAO1 (PaAhpC) is a member of the 2-Cys peroxiredoxin family. Here, we examined the peroxidase and molecular chaperone functions of PaAhpC using a site-directed mutagenesis approach by substitution of Ser and Thr residues with Cys at positions 78 and 105 located between two catalytic cysteines. Substitution of Ser with Cys at position 78 enhanced the chaperone activity of the mutant (S78C-PaAhpC) by approximately 9-fold compared with that of the wild-type protein (WT-PaAhpC). This increased activity may have been associated with the proportionate increase in the high-molecular-weight (HMW) fraction and enhanced hydrophobicity of S78C-PaAhpC. Homology modeling revealed that mutation of Ser(78) to Cys(78) resulted in a more compact decameric structure than that observed in WT-PaAhpC and decreased the atomic distance between the two neighboring sulfur atoms of Cys(78) in the dimer-dimer interface of S78C-PaAhpC, which could be responsible for the enhanced hydrophobic interaction at the dimer-dimer interface. Furthermore, complementation assays showed that S78C-PaAhpC exhibited greatly improved the heat tolerance, resulting in enhanced survival under thermal stress. Thus, addition of Cys at position 78 in PaAhpC modulated the functional shifting of this protein from a peroxidase to a chaperone. PMID:27457208

  3. Mutation of the Inducible ARABIDOPSIS THALIANA CYTOCHROME P450 REDUCTASE2 Alters Lignin Composition and Improves Saccharification1[W][OPEN

    PubMed Central

    Sundin, Lisa; Vanholme, Ruben; Geerinck, Jan; Goeminne, Geert; Höfer, René; Kim, Hoon; Ralph, John; Boerjan, Wout

    2014-01-01

    ARABIDOPSIS THALIANA CYTOCHROME P450 REDUCTASE1 (ATR1) and ATR2 provide electrons from NADPH to a large number of CYTOCHROME P450 (CYP450) enzymes in Arabidopsis (Arabidopsis thaliana). Whereas ATR1 is constitutively expressed, the expression of ATR2 appears to be induced during lignin biosynthesis and upon stresses. Therefore, ATR2 was hypothesized to be preferentially involved in providing electrons to the three CYP450s involved in lignin biosynthesis: CINNAMATE 4-HYDROXYLASE (C4H), p-COUMARATE 3-HYDROXYLASE1 (C3H1), and FERULATE 5-HYDROXYLASE1 (F5H1). Here, we show that the atr2 mutation resulted in a 6% reduction in total lignin amount in the main inflorescence stem and a compositional shift of the remaining lignin to a 10-fold higher fraction of p-hydroxyphenyl units at the expense of syringyl units. Phenolic profiling revealed shifts in lignin-related phenolic metabolites, in particular with the substrates of C4H, C3H1 and F5H1 accumulating in atr2 mutants. Glucosinolate and flavonol glycoside biosynthesis, both of which also rely on CYP450 activities, appeared less affected. The cellulose in the atr2 inflorescence stems was more susceptible to enzymatic hydrolysis after alkaline pretreatment, making ATR2 a potential target for engineering plant cell walls for biofuel production. PMID:25315601

  4. Mutation of the Light-Induced Yellow Leaf 1 Gene, Which Encodes a Geranylgeranyl Reductase, Affects Chlorophyll Biosynthesis and Light Sensitivity in Rice

    PubMed Central

    Yuan, Yuan; Zhu, Jinyan; Wang, Man; Yuan, Fuhai; Wu, Shujun; Wang, Zhiqin; Yi, Chuandeng; Xu, Tinghua; Ryom, MyongChol; Gu, Minghong; Liang, Guohua

    2013-01-01

    Chlorophylls (Chls) are crucial for capturing light energy for photosynthesis. Although several genes responsible for Chl biosynthesis were characterized in rice (Oryza sativa), the genetic properties of the hydrogenating enzyme involved in the final step of Chl synthesis remain unknown. In this study, we characterized a rice light-induced yellow leaf 1-1 (lyl1-1) mutant that is hypersensitive to high-light and defective in the Chl synthesis. Light-shading experiment suggested that the yellowing of lyl1-1 is light-induced. Map-based cloning of LYL1 revealed that it encodes a geranylgeranyl reductase. The mutation of LYL1 led to the majority of Chl molecules are conjugated with an unsaturated geranylgeraniol side chain. LYL1 is the firstly defined gene involved in the reduction step from Chl-geranylgeranylated (ChlGG) and geranylgeranyl pyrophosphate (GGPP) to Chl-phytol (ChlPhy) and phytyl pyrophosphate (PPP) in rice. LYL1 can be induced by light and suppressed by darkness which is consistent with its potential biological functions. Additionally, the lyl1-1 mutant suffered from severe photooxidative damage and displayed a drastic reduction in the levels of α-tocopherol and photosynthetic proteins. We concluded that LYL1 also plays an important role in response to high-light in rice. PMID:24058671

  5. Enhancement of the Chaperone Activity of Alkyl Hydroperoxide Reductase C from Pseudomonas aeruginosa PAO1 Resulting from a Point-Specific Mutation Confers Heat Tolerance in Escherichia coli

    PubMed Central

    Lee, Jae Taek; Lee, Seung Sik; Mondal, Suvendu; Tripathi, Bhumi Nath; Kim, Siu; Lee, Keun Woo; Hong, Sung Hyun; Bai, Hyoung-Woo; Cho, Jae-Young; Chung, Byung Yeoup

    2016-01-01

    Alkyl hydroperoxide reductase subunit C from Pseudomonas aeruginosa PAO1 (PaAhpC) is a member of the 2-Cys peroxiredoxin family. Here, we examined the peroxidase and molecular chaperone functions of PaAhpC using a site-directed mutagenesis approach by substitution of Ser and Thr residues with Cys at positions 78 and 105 located between two catalytic cysteines. Substitution of Ser with Cys at position 78 enhanced the chaperone activity of the mutant (S78C-PaAhpC) by approximately 9-fold compared with that of the wild-type protein (WT-PaAhpC). This increased activity may have been associated with the proportionate increase in the high-molecular-weight (HMW) fraction and enhanced hydrophobicity of S78C-PaAhpC. Homology modeling revealed that mutation of Ser78 to Cys78 resulted in a more compact decameric structure than that observed in WT-PaAhpC and decreased the atomic distance between the two neighboring sulfur atoms of Cys78 in the dimer-dimer interface of S78C-PaAhpC, which could be responsible for the enhanced hydrophobic interaction at the dimer-dimer interface. Furthermore, complementation assays showed that S78C-PaAhpC exhibited greatly improved the heat tolerance, resulting in enhanced survival under thermal stress. Thus, addition of Cys at position 78 in PaAhpC modulated the functional shifting of this protein from a peroxidase to a chaperone. PMID:27457208

  6. Details in the catalytic mechanism of mammalian thioredoxin reductase 1 revealed using point mutations and juglone-coupled enzyme activities.

    PubMed

    Xu, Jianqiang; Cheng, Qing; Arnér, Elias S J

    2016-05-01

    The mammalian selenoprotein thioredoxin reductase 1 (TrxR1) is a key enzyme in redox regulation, antioxidant defense, and cellular growth. TrxR1 can catalyze efficient reduction of juglone (5-hydroxy-1,4-naphthoquinone; walnut toxin) in a reaction which, in contrast to reduction of most other substrates of TrxR1, is not dependent upon an intact selenocysteine (Sec, U) residue of the enzyme. Using a number of TrxR1 mutant variants, we here found that a sole Cys residue at the C-terminal tail of TrxR1 is required for high-efficiency juglone-coupled NADPH oxidase activity of Sec-deficient enzyme, occurring with mixed one- and two-electron reactions producing superoxide. The activity also utilizes the FAD and the N-terminal redox active disulfide/dithiol motif of TrxR1. If a sole Cys residue at the C-terminal tail of TrxR1, in the absence of Sec, was moved further towards the C-terminal end of the protein compared to its natural position at residue 497, juglone reduction was, surprisingly, further increased. Ala substitutions of Trp407, Asn418 and Asn419 in a previously described "guiding bar", thought to mediate interactions of the C-terminal tail of TrxR1 with the FAD/dithiol site at the N-terminal domain of the other subunit in the dimeric enzyme, lowered turnover with juglone about 4.5-fold. Four residues of Sec-deficient TrxR1 were found to be easily arylated by juglone, including the Cys residue at position 497. Based upon our observations we suggest a model for involvement of the juglone-arylated C-terminal motif of TrxR1 to explain its high activity with juglone. This study thus provides novel insights into the catalytic mechanisms of TrxR1. One-electron juglone reduction by TrxR1 producing superoxide should furthermore contribute to the well-known prooxidant cytotoxicity of juglone. PMID:26898501

  7. The Association of Methylenetetrahydrofolate Reductase Genotypes with the Risk of Childhood Leukemia in Taiwan

    PubMed Central

    Chang, Wen-Shin; Ji, Hong-Xue; Hsiao, Chieh-Lun; Miao, Chia-En; Hsu, Yuan-Nian; Bau, Da-Tian

    2015-01-01

    Background Acute lymphoblastic leukemia (ALL) is the most prevalent type of pediatric cancer, the causes of which are likely to involve an interaction between genetic and environmental factors. To evaluate the effects of the genotypic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) on childhood ALL risk in Taiwan, two well-known polymorphic genotypes of MTHFR, C677T (rs1801133) and A1298C (rs1801131), were analyzed to examine the extent of their associations with childhood ALL susceptibility and to discuss the MTHFR genotypic contribution to childhood ALL risk among different populations. Methodology/Principal Findings In total, 266 patients with childhood ALL and an equal number of non-cancer controls recruited were genotyped utilizing PCR-RFLP methodology. The MTHFR C677T genotype, but not the A1298C, was differently distributed between childhood ALL and control groups. The CT and TT of MTHFR C677T genotypes were significantly more frequently found in controls than in childhood ALL patients (odds ratios=0.60 and 0.48, 95% confidence intervals=0.42–0.87 and 0.24–0.97, respectively). As for gender, the boys carrying the MTHFR C677T CT or TT genotype conferred a lower odds ratio of 0.51 (95% confidence interval=0.32–0.81, P=0.0113) for childhood ALL. As for age, those equal to or greater than 3.5 years of age at onset of disease carrying the MTHFR C677T CT or TT genotype were of lower risk (odds ratio= 0.43 and 95% confidence interval=0.26–0.71, P=0.0016). Conclusions Our results indicated that the MTHFR C677T T allele was a protective biomarker for childhood ALL in Taiwan, and the association was more significant in male patients and in patients 3.5 years of age or older at onset of disease. PMID:25793509

  8. Sodium arsenite alters cell cycle and MTHFR, MT1/2, and c-Myc protein levels in MCF-7 cells

    SciTech Connect

    Ruiz-Ramos, Ruben; Lopez-Carrillo, Lizbeth; Albores, Arnulfo; Hernandez-Ramirez, Raul U.; Cebrian, Mariano E.

    2009-12-15

    There is limited available information on the effects of arsenic on enzymes participating in the folate cycle. Therefore, our aim was to evaluate the effects of sodium arsenite on the protein levels of methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR) and its further relationship with the expression MT1/2 and c-myc in MCF-7 cells. Arsenite treatment (0-10 muM) for 4 h decreased MTHFR levels in a concentration-dependent fashion without significant effects on DHFR. The effects on MTHFR were observed at arsenite concentrations not significantly affecting cell viability. We also observed an increase in S-phase recruitment at all concentrations probed. Lower concentrations (< 5 muM) induced cell proliferation, showing a high proportion of BrdU-stained cells, indicating a higher DNA synthesis rate. However, higher concentrations (>= 5 muM) or longer treatment periods induced apoptosis. Arsenite also induced dose-dependent increases in MT1/2 and c-Myc protein levels. The levels of MTHFR were inversely correlated to MT1/2 and c-Myc overexpression and increased S-phase recruitment. Our findings indicate that breast epithelial cells are responsive to arsenite and suggest that exposure may pose a risk for breast cancer. The reductions in MTHFR protein levels contribute to understand the mechanisms underlying the induction of genes influencing growth regulation, such as c-myc and MT1/2. However, further research is needed to ascertain if the effects here reported following short-time and high-dose exposure are relevant for human populations chronically exposed to low arsenic concentrations.

  9. Glutamatergic synapse protein composition of wild-type mice is sensitive to in utero MTHFR genotype and the timing of neonatal vigabatrin exposure.

    PubMed

    Zuckerman, Chava; Blumkin, Elinor; Melamed, Osnat; Golan, Hava M

    2015-10-01

    The enzyme methylenetetrahydrofolate-reductase (MTHFR) is part of the homocysteine and folate metabolic pathways. In utero, Mthfr-deficient environment has been reported as a risk factor for neurodevelopmental disorders such as autism and neural tube defects. Neonatal disruption of the GABAergic system is also associated with behavioral outcomes. The interaction between Mthfr deficiency and neonatal exposure to the GABA-potentiating drug vigabatrin (GVG) in mice alters anxiety, memory, and social behavior in a gender-dependent manner. In addition, a gender-dependent enhancement of proteins implicated in excitatory synapse plasticity in the cerebral cortex was shown. Here we show that in utero MTHFR deficiency is sufficient to alter the levels of glutamate receptor subunits GluR1, GluR2, and NR2B in the cerebral cortex and hippocampus of adult offspring with a WT genotype. In addition, FMRP1, CAMKII α and γ, and NLG1 levels in WT offspring were vulnerable to the in utero genotype. These effects depend on brain region and the cellular compartment tested. The effect of in utero MTHFR deficiency varies with the age of neonatal GVG exposure to modify GluR1, NR2A, reelin, CAMKII α, and NLG1 levels. These changes in molecular composition of the glutamatergic synapse were associated with increased anxiety-like behavior. Complex, multifactorial disorders of the nervous system show significant association with several genetic and environmental factors. Our data exemplify the contribution of an in utero MTHFR-deficient environment and early exposure to an antiepileptic drug to the basal composition of the glutamatergic synapses. The robust effect is expected to alter synapse function and plasticity and the cortico-hippocampal circuitry. PMID:26235956

  10. MTHFR gene A1298C polymorphisms are associated with breast cancer risk among Chinese population: evidence based on an updated cumulative meta-analysis

    PubMed Central

    Wang, Yadong; Yang, Haiyan; Duan, Guangcai

    2015-01-01

    Objectives: Published studies on the association between methylenetetrahydrofolate reductase (MTHFR) gene A1298C polymorphisms and breast cancer risk among Chinese population have yielded conflicting results. The purpose of this study was to clarify the association between MTHFR gene A1298C polymorphisms and breast cancer risk among Chinese population. Methods: Systematic searches were performed through the database of Medline/PubMed, Science Direct, Elsevier, CNKI and Wanfang Medical Online. Results: Overall, a significantly increased risk of breast cancer was observed among the subjects carrying MTHFR gene A1298C AC+CC genotype (odds ratio [OR]=1.05 with 95% confidence interval [CI]: 1.01-1.10) as compared to those carrying AA genotype among total Chinese population. We did not observe any significant association between MTHFR gene A1298C polymorphisms and the risk of breast cancer under the additional genetic models of AC vs. AA, CC vs. AA and C-allele vs. A-allele (OR=1.00 with 95% CI: 0.97-1.02, OR=1.01 with 95% CI: 1.00-1.02 and OR=1.00 with 95% CI: 0.99-1.02, respectively). The cumulative meta-analysis showed similar results. In subgroup analysis, we observed subjects carrying AC+CC genotype had an increased breast cancer risk compared with those carrying AA genotype among the studies of sample size less than 1000. We did not observe any significant association between MTHFR gene A1298C polymorphisms and breast cancer risk in additional subgroup analyses. Conclusions: Our results suggest that MTHFR gene A1298C AC+CC genotype may be a risk factor for the development of breast cancer among Chinese population. Well-designed studies with a large sample size are needed to further confirm our findings. PMID:26884927

  11. Mutation for Nonsyndromic Mental Retardation in the trans-2-Enoyl-CoA Reductase TER Gene Involved in Fatty Acid Elongation Impairs the Enzyme Activity and Stability, Leading to Change in Sphingolipid Profile*

    PubMed Central

    Abe, Kensuke; Ohno, Yusuke; Sassa, Takayuki; Taguchi, Ryo; Çalışkan, Minal; Ober, Carole; Kihara, Akio

    2013-01-01

    Very long-chain fatty acids (VLCFAs, chain length >C20) exist in tissues throughout the body and are synthesized by repetition of the fatty acid (FA) elongation cycle composed of four successive enzymatic reactions. In mammals, the TER gene is the only gene encoding trans-2-enoyl-CoA reductase, which catalyzes the fourth reaction in the FA elongation cycle. The TER P182L mutation is the pathogenic mutation for nonsyndromic mental retardation. This mutation substitutes a leucine for a proline residue at amino acid 182 in the TER enzyme. Currently, the mechanism by which the TER P182L mutation causes nonsyndromic mental retardation is unknown. To understand the effect of this mutation on the TER enzyme and VLCFA synthesis, we have biochemically characterized the TER P182L mutant enzyme using yeast and mammalian cells transfected with the TER P182L mutant gene and analyzed the FA elongation cycle in the B-lymphoblastoid cell line with the homozygous TER P182L mutation (TERP182L/P182L B-lymphoblastoid cell line). We have found that TER P182L mutant enzyme exhibits reduced trans-2-enoyl-CoA reductase activity and protein stability, thereby impairing VLCFA synthesis and, in turn, altering the sphingolipid profile (i.e. decreased level of C24 sphingomyelin and C24 ceramide) in the TERP182L/P182L B-lymphoblastoid cell line. We have also found that in addition to the TER enzyme-catalyzed fourth reaction, the third reaction in the FA elongation cycle is affected by the TER P182L mutation. These findings provide new insight into the biochemical defects associated with this genetic mutation. PMID:24220030

  12. A case of vascular parkinsonism associated with hyperhomocysteinemia and methylenetetrahydrofolate reductase gene variant (C677T).

    PubMed

    Hara, Kenju; Onda, Keigo; Ouchi, Haruka; Shibano, Ken; Ishiguro, Hideaki

    2016-03-01

    A 56-year-old man, who presented with 6 years history of difficulty in walking, was diagnosed as having vascular parkinsonism on the basis of the clinical findings of parkinsonism, pyramidal sign and the brain MRI findings of multiple lacunar infarction. Although he did not have hypertension, he had hyperhomocysteinemia and homozygous methylenetetrahydrofolate reductase (MTHFR) gene variant (C677T) as risk factors for ischemic stroke. Recent studies have shown that hyperhomocysteinemia and MTHFR gene variant are associated with small-vessel disease, suggesting that these risk factors may underlie vascular parkinsonism, particularly in patients lacking hypertension and in those with a relatively younger age at onset of this disease. PMID:26797478

  13. Renal failure after high-dose methotrexate in a child homozygous for MTHFR C677T polymorphism.

    PubMed

    Turello, Rita; Rentsch, Katharina; Di Paolo, Ermindo; Popovic, Maja Beck

    2008-01-01

    We report the case of an 11-year-old female treated for mediastinal T-cell lymphoma who presented renal failure following the second cycle of high-dose methotrexate (HDMTX). Because of life threatening plasma methotrexate (MTX) levels, carboxypeptidase G2 (CPDG2) was administered resulting in a dramatic decrease within 1 hr. The patient recovered from renal failure and no other side effects were observed. Homozygosity for the methylentetrahydrofolate reductase (MTHFR) C677T polymorphism diagnosed by molecular genetic analysis was the only explanation for this toxicity. PMID:17387702

  14. Maternal polymorphisms 677C-T and 1298A-C of MTHFR, and 66A-G MTRR genes: is there any relationship between polymorphisms of the folate pathway, maternal homocysteine levels, and the risk for having a child with Down syndrome?

    PubMed

    Martínez-Frías, María-Luisa; Pérez, Belén; Desviat, Lourdes R; Castro, Margarita; Leal, Fátima; Rodríguez, Laura; Mansilla, Elena; Martínez-Fernández, María-Luisa; Bermejo, Eva; Rodríguez-Pinilla, Elvira; Prieto, David; Ugarte, Magdalena

    2006-05-01

    This study was aimed at analyzing the effect of mutations in three non-synonymous SNP genes (677C > T and 1298A > C of the methylenetetrahydrofolate reductase (MTHFR) gene, and 66A > G in the MTRR gene) on total plasmatic homocysteine (Hcy), in 91 mothers of Down syndrome (DS) infants and 90 control mothers. The comparison of both groups of mothers is a new way to determine if those mutations and their interactions increase the risk for DS. Material came from the case-control network of the Spanish Collaborative Study of Congenital Malformations (ECEMC). Using a general lineal model in a backwards step, we performed the analyses including the different mutations, maternal age, the fact that each mother had a DS or a control infant, and all possible interactions of these variables, in the models, being maternal Hcy the continuous dependent variable. In another model, maternal folic acid intake during the third trimester of pregnancy was added. The results from both models were essentially the same: Hcy levels variability differs from case mothers to control ones, the presence of the MTHFR1298A > C polymorphism also affects significantly the Hcy variance, as it does the statistical interaction between the mutations MTRR66A > G and MTHFR1298A > C in the mother. In this sense, the interaction between different polymorphisms may totally modify their individual effects, and some of those effects are different in mothers of DS children and in controls' mothers. For instance, only two mutations in MTRR66 (GGAA) in mothers of control infants increase the reference maternal Hcy level in 4.66 units, and the individual effect of the genotype with only two mutations in the MTHFR1298 gene (AACC) increases the reference Hcy level in 12.74 units. However, the presence of the four mutations (GGCC) interacts giving a statistically significant decrease in 6.00 units in the level of Hcy in control mothers. On the contrary, in mothers of DS infants, the sole presence of two mutations

  15. The binding sites on human heme oxygenase-1 for cytochrome p450 reductase and biliverdin reductase.

    PubMed

    Wang, Jinling; de Montellano, Paul R Ortiz

    2003-05-30

    Human heme oxygenase-1 (hHO-1) catalyzes the NADPH-cytochrome P450 reductase-dependent oxidation of heme to biliverdin, CO, and free iron. The biliverdin is subsequently reduced to bilirubin by biliverdin reductase. Earlier kinetic studies suggested that biliverdin reductase facilitates the release of biliverdin from hHO-1 (Liu, Y., and Ortiz de Montellano, P. R. (2000) J. Biol. Chem. 275, 5297-5307). We have investigated the binding of P450 reductase and biliverdin reductase to truncated, soluble hHO-1 by fluorescence resonance energy transfer and site-specific mutagenesis. P450 reductase and biliverdin reductase bind to truncated hHO-1 with Kd = 0.4 +/- 0.1 and 0.2 +/- 0.1 microm, respectively. FRET experiments indicate that biliverdin reductase and P450 reductase compete for binding to truncated hHO-1. Mutation of surface ionic residues shows that hHO-1 residues Lys18, Lys22, Lys179, Arg183, Arg198, Glu19, Glu127, and Glu190 contribute to the binding of cytochrome P450 reductase. The mutagenesis results and a computational analysis of the protein surfaces partially define the binding site for P450 reductase. An overlapping binding site including Lys18, Lys22, Lys179, Arg183, and Arg185 is similarly defined for biliverdin reductase. These results confirm the binding of biliverdin reductase to hHO-1 and define binding sites of the two reductases. PMID:12626517

  16. Polymorphisms of glutathione S-transferase and methylenetetrahydrofolate reductase genes in Moldavian patients with ulcerative colitis: Genotype-phenotype correlation

    PubMed Central

    Varzari, Alexander; Deyneko, Igor V.; Tudor, Elena; Turcan, Svetlana

    2015-01-01

    Background Glutathione S-transferases (GSTM1, GSTT1, and GSTP1) and methylenetetrahydrofolate reductase (MTHFR) are important enzymes for protection against oxidative stress. In addition, MTHFR has an essential role in DNA synthesis, repair, and methylation. Their polymorphisms have been implicated in the pathogenesis of ulcerative colitis (UC). The aim of the present study was to investigate the role of selected polymorphisms in these genes in the development of UC in the Moldavian population. Methods In a case-control study including 128 UC patients and 136 healthy individuals, GSTM1 and GSTT1 genotypes (polymorphic deletions) were determined using multiplex polymerase chain reaction (PCR). The GSTP1 rs1695 (Ile105Val), MTHFR rs1801133 (C677T), and MTHFR rs1801131 (A1298C) polymorphisms were studied with restriction fragment length polymorphism (RFLP) analysis. Genotype–phenotype correlations were examined using logistic regression analysis. Results None of the genotypes, either alone or in combination, showed a strong association with UC. The case-only sub-phenotypic association analysis showed an association of the MTHFR rs1801133 polymorphism with the extent of UC under co-dominant (p corrected = 0.040) and recessive (p corrected = 0.020; OR = 0.15; CI = 0.04–0.63) genetic models. Also, an association between the MTHFR rs1801131 polymorphism and the severity of UC was reported for the over-dominant model (p corrected = 0.023; coefficient = 0.32; 95% CI = 0.10–0.54). Conclusion The GST and MTHFR genotypes do not seem to be a relevant risk factor for UC in our sample. There was, however, evidence that variants in MTHFR may influence the clinical features in UC patients. Additional larger studies investigating the relationship between GST and MTHFR polymorphisms and UC are required. PMID:26862484

  17. MTHFR polymorphisms, dietary folate intake, and breast cancer risk: results from the Shanghai Breast Cancer Study.

    PubMed

    Shrubsole, Martha J; Gao, Yu-Tang; Cai, Qiuyin; Shu, Xiao Ou; Dai, Qi; Hébert, James R; Jin, Fan; Zheng, Wei

    2004-02-01

    Folate plays an important role in DNA methylation, synthesis, and repair; intake has been associated with breast cancer. The folate-metabolizing enzyme, methylenetetrahydrofolate reductase (MTHFR) is polymorphic at nucleotides 677 (C-->T) and 1298 (A-->C), resulting in allozymes with decreased activity. We evaluated these two common polymorphisms and their effects on the folate intake and breast cancer risk association in a population-based case-control study of 1144 breast cancer cases and 1236 controls using a PCR-RFLP-based assay. All subjects completed in-person interviews, which included a food frequency questionnaire. Unconditional logistic regression models were used to calculate odds ratios and their 95% confidence intervals, after adjusting for potential confounding factors. Cases and controls were similar in the distribution of MTHFR polymorphisms at codons 677 (41.4% cases and 41.8% controls carried the T allele) and 1298 (17.6% cases and 17.5% controls carried the C allele). An inverse association of breast cancer risk with folate intake was observed in all genotype groups, particularly among subjects with the 677TT genotype. Compared with those with the 677CC genotype and high folate, the adjusted odds ratios (95% confidence intervals) associated with low folate intake were 1.94 (1.15-3.26), 2.17 (1.34-3.51), and 2.51 (1.37-4.60) for subjects who had CC, CT, and TT genotypes (p for interaction, 0.05). No modifying effect of A1298C genotypes on the association of folate intake with breast cancer risk was observed. Results of this study suggest that the MTHFR C677T polymorphisms may modify the association between dietary folate intake and breast cancer risk. PMID:14973091

  18. Association of MTHFR C677T and A1298C gene polymorphisms with hypertension

    PubMed Central

    Alghasham, Abdullah; Settin, Ahmad A; Ali, Ahmad; Dowaidar, Moataz; Ismail, Hisham

    2012-01-01

    Objectives To check for the association of genetic polymorphisms related to the methylenetetrahydrofolate reductase (MTHFR) gene namely C677T and A1298C with hypertension in Saudi affected subjects from Qassim region. Subjects and methods Participants included 123 Saudi hypertensive cases (83 males and 40 females) in addition to 250 (142 males and 108 females) unrelated healthy controls from the same locality. Their age mean ±SD was 50.93 ± 15.43 years. For all subjects, DNA was extracted followed by real-time PCR amplifications for characterization of genotypes and alleles related to MTHFR C677T and A1298C gene polymorphisms Results Total cases showed significantly higher carriage rate for the mutant allele 677T compared to controls (40.7% vs. 26%, OR=1.9, 95% CI= 1.2–3.1) with a lower frequency of the wild type 677CC genotype (59.3% vs. 74%, p=0.004). The same was observed among cases-subgroups of hypertension associated with obesity with a notably higher odds ratio (OR=2.6, 95% CI=1.3–5.01, p=0.004). Total cases showed also significantly higher frequency of mutant 1298 C allele carriage rate compared to controls (59.3% vs. 42.4%, OR=1.98, 95% CI= 1.3–3.1) with a lower frequency of the normal AA genotype (40.7% vs. 57.6%, p=0.003). The same was observed among cases-subgroups of hypertension associated with both diabetes and obesity and among cases of hypertension with obesity, also with higher odds ratio (OR=2.6 and 2.2 respectively). Conclusion This work showed that genetic polymorphisms related to the MTHFR gene are associated with the risk of hypertension particularly when accompanied with obesity and diabetes among Saudi subjects. PMID:23267299

  19. The association between methylenetetrahydrofolate reductase gene C677T polymorphisms and breast cancer risk in Chinese population.

    PubMed

    Wang, Yadong; Yang, Haiyan; Gao, Huiyan; Wang, Haiyu

    2015-12-01

    With great interest, we read the recent article entitled "Methylenetetrahydrofolate reductase polymorphisms and breast cancer risk in Chinese population: a meta-analysis of 22 case-control studies" published online in Tumor Biology, 2014, 35: 1695-1701. This article suggests that methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism was significantly associated with breast cancer risk in Chinese population. The result is encouraging. Nevertheless, three key issues in this meta-analysis are worth noticing. PMID:26537580

  20. Alteration of the alkaloid profile in genetically modified tobacco reveals a role of methylenetetrahydrofolate reductase in nicotine N-demethylation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of the tetrahydrofolate (THF)-mediated one-carbon (C1) metabolic network. This enzyme catalyzes reduction of 5,10-methylene-THF to 5-methyl-THF. The latter donates its methyl group to homocysteine forming Met, which is then used for the syn...

  1. Role of MTHFR C677T and MTR A2756G polymorphisms in thyroid and breast cancer development.

    PubMed

    Zara-Lopes, T; Gimenez-Martins, A P A; Nascimento-Filho, C H V; Castanhole-Nunes, M M U; Galbiatti-Dias, A L S; Padovani-Júnior, J A; Maniglia, J V; Francisco, J L E; Pavarino, E C; Goloni-Bertollo, E M

    2016-01-01

    Folate metabolism is essential for DNA synthesis and repair. Alterations in genes that participate in folate metabolism can be associated with several types of malignant neoplasms, including thyroid and breast cancer. In the present case-control study, we examined the association between methylenetetrahydrofolate reductase (MTHFR C677T, rs1801133) and methionine synthase (MTR A2756G, rs1805087) polymorphisms and risk for thyroid and breast cancer. Polymerase chain reaction-restriction fragment length technique was used to determine the specific genotypes in the genes of interest. Statistical analysis was performed by multiple logistic regression test. We found an association between MTHFR C677T polymorphism and risks to both thyroid (OR = 2.50; 95%CI = 1.15-5.46; P = 0.02) and breast cancer (OR = 2.53; 95%CI = 1.08-5.93; P = 0.03). Tobacco consumption and high body mass index were also associated with thyroid cancer. In addition, increased age (≥50 years) and alcohol consumption were found to be associated with breast cancer. Our results indicated that MTHFR C677T is significantly associated with thyroid and breast cancer risks. Thus, these factors may be used as potential prognostic markers for thyroid and breast cancers. PMID:27173331

  2. Pulmonary Embolism in a Sarcoidosis Patient Double Heterozygous for Methylenetetrahydrofolate Reductase Gene Polymorphisms and Factor V Leiden and Homozygous for the D-Allele of Angiotensin Converting Enzyme Gene

    PubMed Central

    El-Majzoub, Nadim; Mahfouz, Rami; Kanj, Nadim

    2015-01-01

    Sarcoidosis is a multisystem granulomatous disease of unknown etiology and pathogenesis. It presents in patients younger than 40 years of age. The lungs are the most commonly affected organ. Till the present day, there is no single specific test that will accurately diagnose sarcoidosis; as a result, the diagnosis of sarcoidosis relies on a combination of clinical, radiologic, and histologic findings. Patients with sarcoidosis have been found to have an increased risk of pulmonary embolism compared to the normal population. MTHFR and factor V Leiden mutations have been reported to increase the risk of thrombosis in patients. We hereby present a case of a middle aged man with sarcoidosis who developed a right main pulmonary embolism and was found to be double heterozygous for methylenetetrahydrofolate reductase gene polymorphisms and factor V Leiden and homozygous for the D-allele of the angiotensin converting enzyme gene. PMID:26347783

  3. Association of neural tube defects in children of mothers with MTHFR 677TT genotype and abnormal carbohydrate metabolism risk: a case-control study.

    PubMed

    Cadenas-Benitez, N M; Yanes-Sosa, F; Gonzalez-Meneses, A; Cerrillos, L; Acosta, D; Praena-Fernandez, J M; Neth, O; Gomez de Terreros, I; Ybot-González, P

    2014-01-01

    Abnormalities in maternal folate and carbohydrate metabolism have both been shown to induce neural tube defects (NTD) in humans and animal models. However, the relationship between these two factors in the development of NTDs remains unclear. Data from mothers of children with spina bifida seen at the Unidad de Espina Bífida del Hospital Infantil Virgen del Rocío (case group) were compared to mothers of healthy children with no NTD (control group) who were randomly selected from patients seen at the outpatient ward in the same hospital. There were 25 individuals in the case group and 41 in the control group. Analysis of genotypes for the methylenetetrahydrofolate reductase (MTHFR) 677CT polymorphism in women with or without risk factors for abnormal carbohydrate metabolism revealed that mothers who were homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism were more likely to have offspring with spina bifida and high levels of homocysteine, compared to the control group. The increased incidence of NTDs in mothers homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism stresses the need for careful metabolic screening in pregnant women, and, if necessary, determination of the MTHFR 677CT genotype in those mothers at risk of developing abnormal carbohydrate metabolism. PMID:24737468

  4. Association between MTHFR C677T Polymorphism and Risk of Acute Lymphoblastic Leukemia: A Meta-Analysis Based on 51 Case-Control Studies

    PubMed Central

    Li, Su-yi; Ye, Jie-yu; Liang, En-yu; Zhou, Li-xia; Yang, Mo

    2015-01-01

    Background Studies and systematic reviews have reached inconsistent conclusions on the role of 5, 10-methylenetetrahydrofolate reductase (MTHFR) polymorphism C677T in acute lymphoblastic leukemia (ALL) risk. Material/Methods The present meta-analysis comprising of 51 case-control studies, including 7892 cases and 14 280 controls was performed to reevaluate the association between MTHFR C677T polymorphism and ALL risk. Results Statistical differences were found in the dominant model (TT+CT vs. CC, odd ratio (OR)=0.89, 95% CI, 0.79–1.00, P=0.04) and the CT vs. CC (OR=0.89, 95% CI, 0.80–1.00, P=0.05), but not in the allele contrast model (T vs. C, OR=0.92, 95% CI, 0.84–1.01, P=0.08), additive model (TT vs. CC, OR=0.87, 95% CI, 0.73–1.05, P=0.15), or recessive model (TT vs. CT+CC, OR=0.94, 95% CI, 0.81–1.10, P=0.44) in overall populations. In the subgroup analyses stratified by age (children and adults) and ethnicity (Asian and Caucasian), no significant associations between MTHFR C677T polymorphism and ALL risk were observed. Conclusions The current study found no sufficient evidence of a protective role of MTHFR C677T polymorphism in ALL susceptibility. PMID:25761797

  5. Association between MTHFR polymorphisms and congenital heart disease: a meta-analysis based on 9,329 cases and 15,076 controls.

    PubMed

    Xuan, Chao; Li, Hui; Zhao, Jin-Xia; Wang, Hong-Wei; Wang, Yi; Ning, Chun-Ping; Liu, Zhen; Zhang, Bei-Bei; He, Guo-Wei; Lun, Li-Min

    2014-01-01

    The aim of our study was to evaluate the association between polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and the risk for congenital heart disease (CHD). Electronic literature databases were searched to identify eligible studies published before Jun, 2014. The association was assessed by the odds ratio (OR) with a 95% confidence interval (CI). The publication bias was explored using Begg's test. Sensitivity analysis was performed to evaluate the stability of the crude results. A total of 35 studies were included in this meta-analysis. For the MTHFR C677T polymorphism, we detected significant association in all genetic models for Asian children and the maternal population. Significant association was also detected in T vs. C for a Caucasian paediatric population (OR = 1.163, 95% CI: 1.008-1.342) and in both T vs. C (OR = 1.125, 95% CI: 1.043-1.214) and the dominant model (OR = 1.216, 95% CI:b1.096-1.348) for a Caucasian maternal population. For the MTHFR A1298C polymorphism, the association was detected in CC vs. AC for the Caucasian paediatric population (OR = 1.484, 95% CI: 1.035-2.128). Our results support the MTHFR -677T allele as a susceptibility factor for CHD in the Asian maternal population and the -1298 C allele as a risk factor in the Caucasian paediatric population. PMID:25472587

  6. MTHFR polymorphisms' influence on outcome and toxicity in acute lymphoblastic leukemia patients.

    PubMed

    Chiusolo, Patrizia; Reddiconto, Giovanni; Farina, Giuliana; Mannocci, Alice; Fiorini, Alessia; Palladino, Mariangela; La Torre, Giuseppe; Fianchi, Luana; Sorà, Federica; Laurenti, Luca; Leone, Giuseppe; Sica, Simona

    2007-12-01

    Recently the influence of polymorphisms of different genes involved in metabolism of chemoterapic agents have been studied especially in childhood acute lymphoblastic leukemia (ALL). We evaluated the influence of C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) polymorphisms on time to relapse and survival and on methotrexate (MTX) toxicity in 82 ALL adult patients. Relapse free survival and event free survival between homozygous wild-type and variant patients in both polymorphisms were not significantly different. However, we observed an association between 677TT variant and survival in a subset of ALL patients homogenously treated with MTX-based maintenance (p=0.02). In the same subgroup we confirmed the role of 677TT variant on toxicity during MTX treatment (p=0.003). PMID:17512587

  7. MTHFR A1298C and C677T gene polymorphisms and susceptibility to chronic myeloid leukemia in Egypt.

    PubMed

    Aly, Rabab M; Taalab, Mona M; Ghazy, Hayam F

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme regulating the intracellular folate metabolism which plays an important role in carcinogenesis through DNA methylation. We aimed to evaluate the association between MTHFR A1298C and C677T polymorphisms and the risks of chronic myeloid leukemia (CML). Eighty-five patients with CML and a control group containing 100 healthy, age and sex matched individuals were examined for MTHFR C677T and A1298C polymorphisms using polymerase chain reaction-restriction fragment-length (PCR-RFLP) method. The frequency of 677TT genotype in patients with CML was significantly higher compared to controls (OR=2.513, 95% CI: 0.722-4.086, P=0.025). No such association was shown for heterozygous 677CT (OR=1.010, 95% CI: 0.460-2.218, P=0.981). Moreover, for A1298C genotype, a statistically significant higher frequency of 1298CC was also detected in CML patients compared to control group (OR=1.1816, 95% CI: 0.952-3.573, P=0.036), 0.036). No such statistical significance was demonstrable for heterozygote 1298AC (OR=1.046, 95% CI: 0.740-1.759, P=0.092). In addition, patients with joint 677CT/1298AC or 677TT/1298CC genotypes showed an association with increased risk of CML (OR=1.849, 95% CI: 0.935-2.540, P=0.024; OR=1.915, 95% CI: 1.202-3.845, P=0.020 respectively). .A statistically significant increased risk of resistant to therapy was observed with 677CT and 1298AC genotypes (P=0.001, P=0.002 respectively). We conclude that both MTHFR 677TT and 1298CC polymorphisms have been associated with risk of CML and both 677CT and 1298AC genotypes are associated with higher risk of resistant to therapy. PMID:24966971

  8. Folate intake and the MTHFR C677T genotype influence choline status in young Mexican American women☆

    PubMed Central

    Abratte, Christian M.; Wang, Wei; Li, Rui; Moriarty, David J.; Caudill, Marie A.

    2009-01-01

    Numerous studies have reported a relationship between folate status, the methylenetetrahydrofolate reductase (MTHFR) 677C→T variant and disease risk. Although folate and choline metabolism are inter-related, only limited data are available on the relationship between choline and folate status in humans. This study sought to examine the influences of folate intake and the MTHFR 677C→T variant on choline status. Mexican-American women (n =43; 14 CC, 12 CT and 17 TT) consumed 135 μg/day as dietary folate equivalents (DFE) for 7 weeks followed by randomization to 400 or 800 μg DFE/day for 7 weeks. Throughout the study, total choline intake remained unchanged at ∼350 mg/day. Plasma concentrations of betaine, choline, glycerophosphocholine, phosphatidylcholine and sphingomyelin were measured via LC-MS/MS for Weeks 0, 7 and 14. Phosphatidylcholine and sphingomyelin declined ( P=.001, P=.009, respectively) in response to folate restriction and increased ( P=.08, P=.029, respectively) in response to folate treatment. The increase in phosphatidylcholine occurred in response to 800 ( P=.03) not 400 ( P=.85) μg DFE/day (week×folate interaction, P=.017). The response of phosphatidylcholine to folate intake appeared to be influenced by MTHFR C677T genotype. The decline in phosphatidylcholine during folate restriction occurred primarily in women with the CC or CT genotype and not in the TT genotype (week×genotype interaction, P=.089). Moreover, when examined independent of folate status, phosphatidylcholine was higher ( P <.05) in the TT genotype relative to the CT genotype. These data suggest that folate intake and the MTHFR C677T genotype influence choline status in humans. PMID:17588738

  9. MTHFR genotypes and breast cancer survival after surgery and chemotherapy: a report from the Shanghai Breast Cancer Study.

    PubMed

    Shrubsole, Martha J; Shu, Xiao Ou; Ruan, Zhi Xian; Cai, Qiuyin; Cai, Hui; Niu, Qi; Gao, Yu-Tang; Zheng, Wei

    2005-05-01

    Methylenetetrahydrofolate reductase (MTHFR) regulates the intracellular folates pool for DNA synthesis and methylation. Sequence variations in MTHFR (nucleotides 677 (C-->T) and 1298 (A-->C)) result in allozymes with decreased activity. The 677TT genotype is associated with increased toxicity of methotrexate and increased clinical response to 5-fluorouracil in treatment of cancers including breast cancer. We evaluated MTHFR genotypes and breast cancer survival in a cohort of 1067 Chinese women diagnosed with breast cancer between 1996 and 1998 who received surgery and chemotherapy. Life table method was used to calculate 5-year survival rates. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) after adjusting for potential confounding factors. Median follow-up time was 5.2 years; 5-year survival was 84.6%. Sixty-six percent carried a 677T allele and 31% carried a 1298 C allele. We found that overall 5-year breast cancer survival did not differ significantly across all genotypes (85.3% for 677 CC and 83.8% for 677TT; 83.8% for 1298 AA and 79.1% for 1298 CC). However, carrying the 677T allele was associated with non-significant increased risk of death for subjects with late stage disease (stages III-IV) (HR=1.80, 95% CI: 0.79-4.14 for TT vs. CC, p for trend=0.15), particularly among those who had survived past the second year (HR=2.97, 95% CI: 1.10-7.98, p for trend=0.04). The A1298C genotypes were not significantly associated with risk of death. This study suggests that the MTHFR C677T polymorphisms may affect long-term survival from advanced breast cancer. PMID:15868433

  10. C677T and A1298C Polymorphisms of MTHFR Gene and Their Relation to Homocysteine Levels in Turner Syndrome

    PubMed Central

    Oliveira, Kelly C.; Verreschi, Ieda T.N.; Sugawara, Eduardo K.; Silva, Vanessa C.; Galera, Bianca B.; Galera, Marcial Francis; Bianco, Bianca

    2012-01-01

    Aims: To determine the frequency of C677T and A1298C polymorphisms of the MTHFR gene and correlate them with homocysteine serum levels in patients with Turner syndrome (TS) and controls. Methods: This case–control study included 78 women with TS and a control group of 372 healthy individuals without personal or family history of cardiovascular disease and cancer. C677T (rs1801133) and A1298C (rs1801131) polymorphisms were detected by polymerase chain reaction–restriction fragment-length polymorphism and the TaqMan system, respectively. Homocysteine serum levels were determined by high-performance liquid chromatography. The results were analyzed statistically, and p<0.05 was considered to represent a significant difference. Results: The homocysteine levels change was 13.9+3.3 nM in patients with TS and 8.8+3.2 nM in the control group. No significant difference between groups was found (p=0.348). Single-marker analysis revealed no association between MTHFR C677T polymorphism and TS when genotype (p=0.063) or allelic (p=0.277) distribution was considered. Regarding MTHFR A1298C polymorphism, a statistical difference was found between the TS group and the control group, for both genotype (p<0.0001) and allele (p<0.0001) distribution. Haplotype analysis of 2 MTHFR polymorphisms identified 2 haplotypes—CC and TC—associated with TS (p<0.001 and p=0.0165, respectively). However, homocysteine levels were not higher in patients with haplotype risk. Conclusion: The results suggest that the C677T and A1298C polymorphisms of the MTHFR gene are not related to homocysteine levels in Brazilian patients with TS, despite the differential distribution of the mutated allele C (A1298C) in these patients. Further studies are needed to investigate the possible genetic interaction with homocysteine levels in TS. PMID:22283972

  11. The Association between MTHFR Gene Polymorphisms and Hepatocellular Carcinoma Risk: A Meta-Analysis

    PubMed Central

    Deng, Yan; Huang, Shan; Xu, Juanjuan; Li, Haiwei; Li, Shan; Zhao, Jinmin

    2013-01-01

    Background The association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and hepatocellular carcinoma (HCC) risk was inconsistent and underpowered. To clarify the effects of MTHFR gene polymorphisms on the risk of HCC, a meta-analysis of all available studies relating C677T and/or A1298C polymorphisms of MTHFR gene to the risk of HCC was conducted. Methods The authors searched PubMed, EMBASE, Cochrane Library, Web of Science, and Chinese Biomedical Literature database (CBM) for the period up to July 2012. Data were extracted by two independent authors and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. Metaregression and subgroup analyses were performed to identify the source of heterogeneity. Results Finally, 12 studies with 2,351 cases and 4,091 controls were included for C677T polymorphism and 6 studies with 1,333 cases and 1,878 controls were included for A1298C polymorphism. With respect to A1298C polymorphism, significantly decreased HCC risk was found in the overall population (CC vs. AA: OR = 0.660, 95%CI 0.460–0.946, P = 0.024; recessive model: OR = 0.667, 95%CI = 0.470–0.948, P = 0.024). In subgroup analyses, significantly decreased HCC risk was found in Asian population (CC vs. AA: OR = 0.647, 95%CI = 0.435–0.963; P = 0.032) and population-based studies (CC vs. AA: OR = 0.519, 95%CI = 0.327–0.823; P = 0.005). With respect to C677T polymorphism, no significant association with HCC risk was demonstrated in overall and stratified analyses. Conclusions We concluded that MTHFR A1298C polymorphism may play a protective role in the carcinogenesis of HCC. Further large and well-designed studies are needed to confirm this association. PMID:23457501

  12. Alteration of the Alkaloid Profile in Genetically Modified Tobacco Reveals a Role of Methylenetetrahydrofolate Reductase in Nicotine N-Demethylation1[C][W][OA

    PubMed Central

    Hung, Chiu-Yueh; Fan, Longjiang; Kittur, Farooqahmed S.; Sun, Kehan; Qiu, Jie; Tang, She; Holliday, Bronwyn M.; Xiao, Bingguang; Burkey, Kent O.; Bush, Lowell P.; Conkling, Mark A.; Roje, Sanja; Xie, Jiahua

    2013-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of the tetrahydrofolate (THF)-mediated one-carbon (C1) metabolic network. This enzyme catalyzes the reduction of 5,10-methylene-THF to 5-methyl-THF. The latter donates its methyl group to homocysteine, forming methionine, which is then used for the synthesis of S-adenosyl-methionine, a universal methyl donor for numerous methylation reactions, to produce primary and secondary metabolites. Here, we demonstrate that manipulating tobacco (Nicotiana tabacum) MTHFR gene (NtMTHFR1) expression dramatically alters the alkaloid profile in transgenic tobacco plants by negatively regulating the expression of a secondary metabolic pathway nicotine N-demethylase gene, CYP82E4. Quantitative real-time polymerase chain reaction and alkaloid analyses revealed that reducing NtMTHFR expression by RNA interference dramatically induced CYP82E4 expression, resulting in higher nicotine-to-nornicotine conversion rates. Conversely, overexpressing NtMTHFR1 suppressed CYP82E4 expression, leading to lower nicotine-to-nornicotine conversion rates. However, the reduced expression of NtMTHFR did not affect the methionine and S-adenosyl-methionine levels in the knockdown lines. Our finding reveals a new regulatory role of NtMTHFR1 in nicotine N-demethylation and suggests that the negative regulation of CYP82E4 expression may serve to recruit methyl groups from nicotine into the C1 pool under C1-deficient conditions. PMID:23221678

  13. Functional Inference of Methylenetetrahydrofolate Reductase Gene Polymorphisms on Enzyme Stability as a Potential Risk Factor for Down Syndrome in Croatia

    PubMed Central

    Vraneković, Jadranka; Babić Božović, Ivana; Starčević Čizmarević, Nada; Buretić-Tomljanović, Alena; Ristić, Smiljana; Petrović, Oleg; Kapović, Miljenko; Brajenović-Milić, Bojana

    2010-01-01

    Understanding the biochemical structure and function of the methylenetetrahydrofolate reductase gene (MTHFR) provides new evidence in elucidating the risk of having a child with Down syndrome (DS) in association with two common MTHFR polymorphisms, C677T and A1298C. The aim of this study was to evaluate the risk for DS according to the presence of MTHFR C677T and A1298C polymorphisms as well as the stability of the enzyme configuration. This study included mothers from Croatia with a liveborn DS child (n = 102) or DS pregnancy (n = 9) and mothers with a healthy child (n = 141). MTHFR C677T and A1298C polymorphisms were assessed by PCR-RFLP. Allele/genotype frequencies differences were determined using χ2 test. Odds ratio and the 95% confidence intervals were calculated to evaluate the effects of different alleles/genotypes. No statistically significant differences were found between the frequencies of allele/genotype or genotype combinations of the MTHFR C677T and A1298C polymorphisms in the case and the control groups. Additionally, the observed frequencies of the stable (677CC/1298AA, 677CC/1298AC, 677CC/1298CC) and unstable (677CT/1298AA, 677CT/1298AC, 677TT/1298AA) enzyme configurations were not significantly different. We found no evidence to support the possibility that MTHFR polymorphisms and the stability of the enzyme configurations were associated with risk of having a child with DS in Croatian population. PMID:20592453

  14. Bladder exstrophy-epispadias complex and the role of methylenetetrahydrofolate reductase C677T polymorphism: A case control study

    PubMed Central

    Raman, Venkat Shankar; Bajpai, Minu; Ali, Abid

    2016-01-01

    Purpose: The Bladder Exstrophy-Epispadias Complex (BEEC) is the most serious form of midline abdominal malformation. The etiology of BEEC is unknown and is thought to be multifactorial. Methylenetetrahydrofolate reductase (MTHFR) polymorphism C677T is strongly associated with other midline abnormalities such as neural tube defects. No proper case-control study existed comparing MTHFR polymorphism with BEEC. We sought to find an association with MTHFR polymorphism and patients with bladder exstrophy (BE). Materials and Methods: The design of the study was a case-control study, involving 50 children with BEEC and 50 normal healthy school children. Genetic analysis for MTHFR 677 polymorphism was carried out after DNA extraction and polymerase chain reaction amplification. Epidemiological analysis was done by using the birth defect questionnaire on parents of BEEC. Results: Forty-two classical BE, two cloacal exstrophies (CE), four epispadias, and two exstrophy variant patients were a part of this study. Severe variety of BE had a significant association with C667T MTHFR polymorphism as compared to the normal control population (P = 0.01). Conclusion: C677T MTHFR polymorphism has a strong association with severe variety (CE) of BEEC occurrence. PMID:26862292

  15. Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphisms in Male Partners of Recurrent Miscarriage Couples

    PubMed Central

    Tara, Somayeh-Sadat; Ghaemimanesh, Fatemeh; Zarei, Saeed; Reihani-Sabet, Fakhreddin; Pahlevanzadeh, Zhamak; Modarresi, Mohammad Hosein; Jeddi-Tehrani, Mahmood

    2015-01-01

    Background: Methylenetetrahydrofolate reductase (MTHFR) single-nucleotide polymorphisms (SNPs) C677T and A1298C have been described as strong risk factors for idiopathic recurrent miscarriage (RM). However, very few studies have investigated the association of paternal MTHFR SNPs with RM. The aim of the present study was to evaluate the prevalence of paternal C677T and A1298C SNPs among Iranian RM couples. Methods: The study subjects comprised 225 couples with more than three consecutive pregnancy losses, and 100 control couples with no history of pregnancy complications. All females in the case group had MTHFR polymorphisms; and genotype SNPs were analyzed by PCR-RFLP. Groups were statistically compared using Mann Whitney U-test and Chi-square statistical tests. The p<0.05 were considered significant. Results: Statistically significant difference was detected in the frequency of MTHFR SNPs in male partners of the two groups (p=0.019). Combined heterozygosity of MTHFR polymorphisms was a common phenomenon in the males; 52 (23.1%) and 14 (14%) of males in RM and control groups, respectively. Absence of combined homozygosity for both SNPs in all studied groups/genders was observed. Conclusion: The MTHFR gene composition of male partners of RM couples may contribute to increased risk of miscarriage. PMID:27110516

  16. Folate Intake, MTHFR Polymorphisms, and the Risk of Colorectal Cancer: A Systematic Review and Meta-Analysis

    PubMed Central

    Kennedy, Deborah A.; Stern, Seth J.; Matok, Ilan; Moretti, Myla E.; Sarkar, Moumita; Adams-Webber, Thomasin; Koren, Gideon

    2012-01-01

    Background. The objective was to determine whether relationships exist between the methylene-tetrahydrofolate reductase (MTHFR) polymorphisms and risk of colorectal cancer (CRC) and examine whether the risk is modified by level of folate intake. Methods. MEDLINE, Embase, and SCOPUS were searched to May 2012 using the terms “folic acid,” “folate,” “colorectal cancer,” “methylenetetrahydrofolate reductase,” “MTHFR.” Observational studies were included which (1) assessed the risk of CRC for each polymorphism and/or (2) had defined levels of folate intake for each polymorphism and assessed the risk of CRC. Results. From 910 references, 67 studies met our criteria; hand searching yielded 10 studies. The summary risk estimate comparing the 677CT versus CC genotype was 1.02 (95% CI 0.95–1.10) and for 677TT versus CC was 0.88 (95% CI 0.80–0.96) both with heterogeneity. The summary risk estimates for A1298C polymorphisms suggested no reduced risk. The summary risk estimate for high versus low total folate for the 677CC genotype was 0.70 (95% CI 0.56–0.89) and the 677TT genotype 0.63 (95% CI 0.41–0.97). Conclusion. These results suggest that the 677TT genotype is associated with a reduced risk of developing CRC, under conditions of high total folate intake, and this associated risk remains reduced for both MTHFR 677 CC and TT genotypes. PMID:23125859

  17. Severe methylenetetrahydrofolate reductase deficiency in mice results in behavioral anomalies with morphological and biochemical changes in hippocampus.

    PubMed

    Jadavji, Nafisa M; Deng, Liyuan; Leclerc, Daniel; Malysheva, Olga; Bedell, Barry J; Caudill, Marie A; Rozen, Rima

    2012-06-01

    The brain is particularly sensitive to folate metabolic disturbances, since methyl groups are critical for its functions. Methylenetetrahydrofolate reductase (MTHFR) generates the primary circulatory form of folate required for homocysteine remethylation to methionine. Neurological disturbances have been described in homocystinuria caused by severe MTHFR deficiency. The goal of this study was to determine if behavioral anomalies are present in severe Mthfr-deficient (Mthfr(-/-)) mice and to identify neurobiological changes that could contribute to these anomalies. Adult male mice of 3 Mthfr genotypes (+/+, +/-, -/-) were tested on motor, anxiety, exploratory and cognitive tasks. Volumes (whole brain and hippocampus) and morphology, global DNA methylation, apoptosis, expression of choline acetyltransferase (ChAT) and glucocorticoid receptor (GR), and concentrations of choline metabolites were assessed in hippocampus. Mthfr(-/-) mice had impairments in motor function and in short- and long-term memory, increased exploratory behavior and decreased anxiety. They showed decreased whole brain and hippocampal volumes, reduced thickness of the pyramidal cell layer of CA1 and CA3, and increased apoptosis in hippocampus. There was a disturbance in choline metabolism as manifested by differences in acetylcholine, betaine or glycerophosphocholine concentrations, and by increased ChAT levels. Mthfr(-/-) mice also had increased GR mRNA and protein. Our study has revealed significant anomalies in affective behavior and impairments in memory of Mthfr(-/-) mice. We identified structural changes, increased apoptosis, altered choline metabolism and GR dysregulation in hippocampus. These findings, as well as some similar observations in cerebellum, could contribute to the behavioral changes and suggest that choline is a critical metabolite in homocystinuria. PMID:22521626

  18. MTHFR C677T polymorphism, folic acid and hyperhomocysteinemia in levodopa treated patients with Parkinson's disease.

    PubMed

    Woitalla, D; Kuhn, W; Müller, T

    2004-01-01

    Certain mutations (TT homozygous; CT heterozygous; CC wild-type) of the methylenetetrahydrofolate (MTHFR) gene and long-term levodopa application in patients with Parkinson's disease (PD) support onset of hyperhomocysteinemia. Total plasma homocysteine (t-hcys) depends on B6, B12, folic acid, all of which support remyelination from t-hcys to methionine. Objective of this trial were to compare B6, B12, folic acid and t-hcys levels in plasma of 83 levodopa treated PD patients and 44 controls. PD patients with the CT or TT genotype had significant higher t-hcys levels than controls or PD patients with the CC allele. Concentrations of B6 or B12 did not differ, but folic acid was significant higher in PD patients with the CT mutation. We recommend MTHFR genotyping, t-hcys monitoring and early vitamin supplementation in PD patients. The folic acid increase in PD patients with the CT allele is hypothetically due to an endogenous upregulation of folic acid absorption to decrease t-hcys. PMID:15354385

  19. Might erectile dysfunction be due to the thermolabile variant of methylenetetrahydrofolate reductase?

    PubMed

    Lombardo, F; Sgrò, P; Gandini, L; Dondero, F; Jannini, E A; Lenzi, A

    2004-10-01

    Hyperhomocysteinemia is considered one of the most important cardiovascular risk factors increasing considerably the risk of stroke and myocardial infarction. With respect to endothelial function, direct effects of hyperhomocysteinemia on vascular endothelial cells have been demonstrated through the reduction of endothelial nitric oxide production. In this paper, we report the case of a young man with homozygote genotype mutated with 5-methylenetetrahydrofolate reductase (MTHFR) thermolabile variant who, in the absence of relational stress, developed an erectile dysfunction (ED) refractory to the vasoactive type-V phosphodiesterase (PDE5) inhibitor therapy. After one month of treatment with 5 mg/day folic acid and 1000 microg/day cyanocobalamin, the patient restarted the assumption of 50 mg sildenafil, obtaining satisfying erections during sexual intercourse. We suggest that hyperhomocysteinemia may interfere with penile blood supply and, thus, be responsible for ED. If this relationship is confirmed, plasma levels and urinary homocysteine (HCy) should be evaluated in selected young patients with vascular ED. Furthermore, careful attention should be given to the risk of ED when dealing with this metabolic disturbance. PMID:15648556

  20. Relationship between MTHFR C677T and A1298C gene polymorphisms and complications of type 2 diabetes mellitus in an Emirati population

    PubMed Central

    El Hajj Chehadeh, Sarah W.; Jelinek, Herbert F.; Al Mahmeed, Wael A.; Tay, Guan K.; Odama, Unini O.; Elghazali, Gehad E.B.; Al Safar, Habiba S.

    2016-01-01

    Purpose Type 2 diabetes mellitus (T2DM) is the most common form of diabetes with clinical consequences giving rise to chronic multiple organ complications. Methylenetetrahydrofolate reductase (MTHFR) polymorphisms are genetic variations that have been linked to T2DM, and micro/macrovascular complications. The link between MTHFR and T2DM however is strongly dependent on the ethnic group studied. The objective of this study was to investigate the possible association between two MTHFR polymorphisms (C677T and A1298C) and T2DM and specifically examine if there are any associations with clinical and demographic characteristics among patients in the United Arab Emirates (UAE). Methods The study included 169 T2DM patients and 209 healthy controls. Genomic DNA was isolated and genotyped using TaqMan real-Time PCR assays for the MTHFR C677T and A1298C polymorphisms. Results There were no significant differences in genotype and haplotype distributions observed between groups. A significant association was observed between the C677T polymorphism and history of cerebrovascular accident (CVA) (p = 0.0330), history of nephropathy (p = 0.0280) and levels of LDL cholesterol (p = 0.0409). Also, the A1298C polymorphism was associated with hypertriglyceridemia (p = 0.0305) in T2DM patients. Conclusion These findings demonstrate that the MTHFR gene polymorphisms are not related to T2DM in the Emirati population. However, these polymorphisms can be used as risk markers for CVA, nephropathy, high LDL cholesterol and triglycerides in T2DM patients and allow timely treatment. PMID:27222819

  1. MTHFR C677T genotype influences the isotopic enrichment of one-carbon metabolites in folate-compromised men consuming d9-choline123

    PubMed Central

    Yan, Jian; Wang, Wei; Gregory, Jesse F; Malysheva, Olga; Brenna, J Thomas; Stabler, Sally P; Allen, Robert H; Caudill, Marie A

    2011-01-01

    Background: Homozygosity for the variant 677T allele in the methylenetetrahydrofolate reductase (MTHFR) gene increases the requirement for folate and may alter the metabolic use of choline. The choline adequate intake is 550 mg/d for men, although the metabolic consequences of consuming extra choline are unclear. Objective: Deuterium-labeled choline (d9-choline) as tracer was used to determine the differential effects of the MTHFR C677T genotype and the effect of various choline intakes on the isotopic enrichment of choline derivatives in folate-compromised men. Design: Mexican American men with the MTHFR 677CC or 677TT genotype consumed a diet providing 300 mg choline/d plus supplemental choline chloride for total choline intakes of 550 (n = 11; 4 with 677CC and 7 with 677TT) or 1100 (n = 12; 4 with 677CC and 8 with 677TT) mg/d for 12 wk. During the last 3 wk, 15% of the total choline intake was provided as d9-choline. Results: Low but measurable enrichments of the choline metabolites were achieved, including that of d3-phosphatidylcholine (d3-PtdCho)—a metabolite produced in the de novo pathway via choline-derived methyl groups. Men with the MTHFR 677TT genotype had a higher urinary enrichment ratio of betaine to choline (P = 0.041), a higher urinary enrichment of sarcosine (P = 0.041), and a greater plasma enrichment ratio of d9-betaine to d9-PtdCho with the 1100 mg choline/d intake (P = 0.033). Conclusion: These data show for the first time in humans that choline itself is a source of methyl groups for de novo PtdCho biosynthesis and indicate that the MTHFR 677TT genotype favors the use of choline as a methyl donor. PMID:21123458

  2. Association between MTHFR gene polymorphisms (C677T, A1298C) and genetic susceptibility to prostate cancer: a meta-analysis.

    PubMed

    Chen, P L; Li, W T; Wang, J; Jiang, Y D; Wu, P; Chen, T; Zheng, S B

    2015-01-01

    Genetic polymorphisms (C677T and A1298C) in methylenetetrahydrofolate reductase (MTHFR) were shown to be related to prostate cancer risk in previous studies; however, the results are controversial. We performed a meta-analysis of previous studies and quantitatively estimated these associations. Pubmed, Embase, and Cochrane Library Database were searched for published case-control studies evaluating the association between C677T (or A1298C) and prostate cancer risk. Pooled associations were presented as odds ratios (ORs) along with their 95% confidence intervals. Twenty-one case control studies were identified for meta-analysis that included 21,581 participants. No significant associations were found between the MTHFR polymorphisms C677T or A1298C and prostate cancer risk in our meta-analysis. However, in subgroup analyses, the C677T CT polymorphism was associated with increased prostate cancer risk in East Asians (CT vs CC+TT: OR = 1.324, P = 0.03). The A1298C CC polymorphism in MTHFR was also linked to slightly reduced prostate cancer risk in European residents (CC vs AC+AA: OR = 0.751, P = 0.004; CC vs AA: OR = 0.768, P = 0.011), whereas it was associated with a significantly increased prostate cancer risk in Asian residents (CC vs AA: OR = 1.862, P = 0.006). The C677T CT polymorphism of MTHFR may be a risk factor for prostate cancer in East Asians. The association between the MTHFR A1298C CC genotype and prostate cancer risk may vary within different populations. Large-scale well-designed studies are required to confirm these associations. PMID:26782572

  3. Thioredoxin reductase.

    PubMed

    Mustacich, D; Powis, G

    2000-02-15

    The mammalian thioredoxin reductases (TrxRs) are a family of selenium-containing pyridine nucleotide-disulphide oxidoreductases with mechanistic and sequence identity, including a conserved -Cys-Val-Asn-Val-Gly-Cys- redox catalytic site, to glutathione reductases. TrxRs catalyse the NADPH-dependent reduction of the redox protein thioredoxin (Trx), as well as of other endogenous and exogenous compounds. The broad substrate specificity of mammalian TrxRs is due to a second redox-active site, a C-terminal -Cys-SeCys- (where SeCys is selenocysteine), that is not found in glutathione reductase or Escherichia coli TrxR. There are currently two confirmed forms of mammalian TrxRs, TrxR1 and TrxR2, and it is possible that other forms will be identified. The availability of Se is a key factor determining TrxR activity both in cell culture and in vivo, and the mechanism(s) for the incorporation of Se into TrxRs, as well as the regulation of TrxR activity, have only recently begun to be investigated. The importance of Trx to many aspects of cell function make it likely that TrxRs also play a role in protection against oxidant injury, cell growth and transformation, and the recycling of ascorbate from its oxidized form. Since TrxRs are able to reduce a number of substrates other than Trx, it is likely that additional biological effects will be discovered for TrxR. Furthermore, inhibiting TrxR with drugs may lead to new treatments for human diseases such as cancer, AIDS and autoimmune diseases. PMID:10657232

  4. Homocysteinemia is inversely correlated with platelet count and directly correlated with sE- and sP-selectin levels in females homozygous for C677T methylenetetrahydrofolate reductase.

    PubMed

    Rongioletti, Mauro; Baldassini, Mauro; Papa, Fabrizio; Capoluongo, Ettore; Rocca, Bianca; Cristofaro, Raimondo De; Salvati, Giuseppina; Larciprete, Giovanni; Stroppolo, Annalisa; Angelucci, Piero Antonio; Cirese, Elio; Ameglio, Franco

    2005-01-01

    Plasma homocysteine levels depend in part on the molecular nature of the methylenetetrahydrofolate reductase (MTHFR) and on blood folate intake. Little has been reported on platelet counts in the presence of hyperhomocysteinemia and MTHFR polymorphisms, with the exception of delayed platelet recovery in homozygous MTHFR C677T subjects after treatment with methotrexate for ovarian cancer. The aim of this investigation was to evaluate the possibility of a link between the platelet count and plasma homocysteine levels in different MTHFR variants in 165 female patients. Determinations of plasma homocysteine levels were by ELISA and of MTHFR polymorphisms (A1298C and C677T) were by inverse hybridization. Serum P- and E-selectin concentrations were obtained by ELISA. An inverse correlation (R=-0.88, P<0.001) was observed between blood platelet counts and plasma homocysteine levels in the women homozygous for MTHFR C677T. This correlation did not depend on pregnancy or other variables reported. Serum concentrations of sE- and sP-selectin, markers of endothelial and platelet activation, were significantly and positively correlated with homocysteine levels. These findings suggest that homocysteine affects platelet numbers in women with MTHFR C677T possibly consequent to endothelial and platelet activation. PMID:16011963

  5. A common variant in MTHFR influences response to chemoradiotherapy and recurrence of rectal cancer

    PubMed Central

    Nikas, Jason B; Lee, Janet T; Maring, Elizabeth D; Washechek-Aletto, Jill; Felmlee-Devine, Donna; Johnson, Ruth A; Smyrk, Thomas C; Tawadros, Patrick S; Boardman, Lisa A; Steer, Clifford J

    2015-01-01

    An important determinant of the pathogenesis and prognosis of various diseases is inherited genetic variation. Single-nucleotide polymorphisms (SNPs), variations at a single base position, have been identified in both protein-coding and noncoding DNA sequences, but the vast majority of millions of those variants are far from being functionally understood. Here we show that a common variant in the gene MTHFR [rs1801133 (C>T)] not only influences response to neoadjuvant chemoradiotherapy in patients with rectal cancer, but it also influences recurrence of the disease itself. More specifically, patients with the homozygous ancestral (wild type) genotype (C/C) were 2.91 times more likely (291% increased benefit) to respond to neoadjuvant chemoradiotherapy {95% CI: [1.23, 6.89]; P=0.0150} and 3.25 times more likely (325% increased benefit) not to experience recurrence of the disease {95% CI: [1.37, 7.72]; P=0.0079} than patients with either the heterozygous (C/T) or the homozygous mutation (T/T) genotype. These results identify MTHFR as an important genetic marker and open up new, pharmacogenomic strategies in the treatment and management of rectal cancer. PMID:26693073

  6. Role of Hyperhomocysteinemia and Methylene Tetrahydrofolate Reductase C677T Polymorphism in Idiopathic Portal Vein Thrombosis

    PubMed Central

    Ghaznavi, Habib; Soheili, Zahra; Samiei, Shahram; Soltanpour, Mohammad Soleiman

    2016-01-01

    Purpose: Portal vein thrombosis (PVT) is a rare and life-threatening vascular disorder characterized by obstruction or narrowing of the portal vein. Hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism has been studied in PVT patients with conflicting results. In the present study the association of hyperhomocysteinemia and MTHFR C677T polymorphism with PVT risk was investigated in Iranians. Materials and Methods: Our study population consisted of 10 idiopathic PVT patients and 80 healthy control subjects matched for age and sex. MTHFR C677T polymorphism was genotyped by the polymerase chain reaction technique combined with restriction enzyme fragment length polymorphism (PCR-RFLP) technique and plasma total homocysteine (tHcy) levels were determined by enzyme immunoassay method. Results: Mean plasma tHcy levels were significantly higher in PVT patients (20.2±6.8) than control subjects (10.9±4.7) (P=0.001). Moreover, plasma tHcy levels were significantly higher in 677T allele carriers relative to 677C allele carriers in both PVT patients (P=0.01) and control subjects (P=0.03). Neither homozygote nor heterozygote genotypes of MTHFR C677T polymorphism correlated significantly with PVT risk (P>0.05). Moreover, MTHFR C677T polymorphism didn’t increase the risk of PVT under dominant (CT+TT vs. CC) or recessive (TT vs. CC+CT) genetic models analyzed (P>0.05). The difference in frequency of minor 677T allele between PVT patients and control subjects was not statistically significant (P>0.05). Conclusion: Based on the current study, we suggest that hyperhomocysteinemia constitutes a significant and common risk factor for PVT. Also, MTHFR C677T polymorphism is not a risk factor for PVT but is a contributing factor for elevated plasma tHcy levels. PMID:27051654

  7. The C677T variant in MTHFR modulates associations between blood-based and cerebrospinal fluid biomarkers of neurodegeneration

    PubMed Central

    Roussotte, Florence F.; Narr, Katherine L.; Small, Gary W.

    2016-01-01

    The C677T functional variant in the methylene-tetrahydrofolate reductase (MTHFR) gene results in reduced enzymatic activity and elevated blood levels of homocysteine. Plasma levels of apolipoprotein E (ApoE) are negatively correlated with cerebral amyloid burden, but plasma homocysteine concentrations are associated with increased amyloid-β (Aβ) deposition in the brain. Here, we sought to determine whether associations between low plasma ApoE levels and elevated in-vivo amyloid burden were modulated by carrying the C677T variant. We tested this hypothesis in a large sample of elderly participants from the Alzheimer’s Disease Neuroimaging Initiative. We used general linear models to examine associations between plasma homocysteine concentrations, circulating ApoE levels, cerebrospinal fluid concentrations of Aβ, and their modulation by MTHFR and ApoE genotype. Age, sex, and dementia status were included as covariates in all analyses. Higher circulating levels of ApoE predicted increased cerebrospinal fluid concentrations of Aβ, indicating lower in-vivo burden, in C-allele carriers, but not in homozygotes at the C677T variant, who showed significant elevations in plasma homocysteine levels. This modulation by the MTHFR genotype did not remain significant after controlling for ApoE genotype. In T-homozygotes who do not carry the ApoE-ε4 allele, the relationship between low plasma ApoE levels and an increased risk of dementia is likely obscured by the presence of elevated plasma homocysteine. This report suggests the value of genotyping patients at the C677T functional variant when using plasma ApoE levels as a preclinical biomarker for Alzheimer’s disease. PMID:27380243

  8. The C677T variant in MTHFR modulates associations between blood-based and cerebrospinal fluid biomarkers of neurodegeneration.

    PubMed

    Roussotte, Florence F; Narr, Katherine L; Small, Gary W; Thompson, Paul M

    2016-08-17

    The C677T functional variant in the methylene-tetrahydrofolate reductase (MTHFR) gene results in reduced enzymatic activity and elevated blood levels of homocysteine. Plasma levels of apolipoprotein E (ApoE) are negatively correlated with cerebral amyloid burden, but plasma homocysteine concentrations are associated with increased amyloid-β (Aβ) deposition in the brain. Here, we sought to determine whether associations between low plasma ApoE levels and elevated in-vivo amyloid burden were modulated by carrying the C677T variant. We tested this hypothesis in a large sample of elderly participants from the Alzheimer's Disease Neuroimaging Initiative. We used general linear models to examine associations between plasma homocysteine concentrations, circulating ApoE levels, cerebrospinal fluid concentrations of Aβ, and their modulation by MTHFR and ApoE genotype. Age, sex, and dementia status were included as covariates in all analyses. Higher circulating levels of ApoE predicted increased cerebrospinal fluid concentrations of Aβ, indicating lower in-vivo burden, in C-allele carriers, but not in homozygotes at the C677T variant, who showed significant elevations in plasma homocysteine levels. This modulation by the MTHFR genotype did not remain significant after controlling for ApoE genotype. In T-homozygotes who do not carry the ApoE-ε4 allele, the relationship between low plasma ApoE levels and an increased risk of dementia is likely obscured by the presence of elevated plasma homocysteine. This report suggests the value of genotyping patients at the C677T functional variant when using plasma ApoE levels as a preclinical biomarker for Alzheimer's disease. PMID:27380243

  9. Role of MTHFR C677T gene polymorphism in the susceptibility of schizophrenia: An updated meta-analysis.

    PubMed

    Yadav, Upendra; Kumar, Pradeep; Gupta, Sanjay; Rai, Vandana

    2016-04-01

    Methylenetetrahydrofolate reductase (MTHFR) is the key enzyme of folate/homocysteine metabolic pathway. C677T polymorphism of MTHFR gene was reported as risk factor for congenital defects, metabolic and neuropsychiatric disorders. Numerous case-control studies investigated C677T polymorphism as risk factor for schizophrenia but results of these studies were contradictory. To draw a conclusion, a meta-analysis of all available case-control studies was performed. PubMed, Google Scholar, Springer Link and Elsevier databases were searched for eligible case-control studies. Pooled odds ratio with 95%CI was used as an association measure and all statistical analyses were performed by Open Meta-Analyst and MIX software. Total 38 studies with 10,069 cases and 13,372 controls were included in the present meta-analysis. Results of meta-analysis showed significant associated between C677T polymorphism and risk of schizophrenia (ORTvsC=1.18, 95%CI=1.10-1.27, p=<0.001; ORCTvsCC=1.10, 95%CI=1.04-1.17, p=<0.001; ORTTvsCC=1.40, 95%CI=1.20-1.64, p=<0.001; ORTT+CTvsCC=1.19, 95%CI=1.09-1.30, p=<0.001). We also performed subgroup and sensitivity analyses. Subgroup analysis was done according to ethnicity and significant association was found between C677T polymorphism and risk of schizophrenia in all three ethnic populations-African (OR=2.51; 95%CI=1.86-3.40; p=<0.001), Asian (OR=1.21; 95%CI=1.10-1.33; p=<0.001) and Caucasian (OR=1.07; 95%CI=1.01-1.14; p=0.01). In conclusion the results of the present meta-analysis suggested that the MTHFR C677T polymorphism is a risk factor for schizophrenia. PMID:27025471

  10. A 31 year old woman with essential hypertension grade III and branch retinal vein occlusion with homozygous C677T MTHFR hyperhomocysteinemia and high Lp(a) levels.

    PubMed

    Katsi, Vasiliki; Tousoulis, Dimitris; Chatzistamatiou, Evangelos; Androulakis, Emmanouil; Moustakas, Georgios; Skiadas, Ioannis; Tsioufis, Constantinos; Antoniades, Charalambos; Stefanadis, Christodoulos I; Kallikazaros, Ioannis E

    2010-09-01

    We report a 31-year old woman with essential hypertension grade III and history of branch retinal vein occlusion in the setting of hyperhomocysteinemia due to homozygous MTHFR gene mutation and elevated Lp(a). The patient was treated successfully with antihypertensive treatment, acetylsalicylic acid and multivitamin complex supplementation. PMID:19135738

  11. Association of Methylenetetrahydrofolate Reductase C677T Polymorphism with Hyperhomocysteinemia and Deep Vein Thrombosis in the Iranian Population

    PubMed Central

    Ghaznavi, Habib; Soheili, Zahra; Samiei, Shahram; Soltanpour, Mohammad Soleiman

    2015-01-01

    Purpose: Deep venous thrombosis (DVT) is a common but elusive condition characterized by a high morbidity and mortality rate. The aim of the present study was to investigate the correlation between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism with plasma total homocysteine (tHcy) levels and DVT risk in an Iranian population. Materials and Methods: Our study population consisted of 67 patients with a diagnosis of DVT and 67 healthy subjects as controls. Genotyping of MTHFR C677T polymorphism was performed by the polymerase chain reaction technique combined with restriction enzyme fragment length polymorphism (PCR-RFLP) and measurement of tHcy levels was done by enzyme immunoassay method. Results: Plasma tHcy levels were significantly higher in DVT patients than controls (18.09±7.6 vs. 10.5±4.3, P=0.001). Also, plasma tHcy levels were significantly higher in MTHFR 677TT genotypes compared to 677CC genotypes in both DVT patients (P=0.016) and controls (P=0.03). Neither heterozygote nor homozygote genotypes of MTHFR C677T polymorphism was significantly correlated with DVT (P>0.05). The distribution of MTHFR C677T genotypes was similar between men and women in both DVT patients and controls (P>0.05). Moreover, the frequency of mutant 677T allele did not differ significantly between the two groups (28.3% vs. 21.6%, P=0.15). Conclusion: Based on this study, we propose that hyperhomocysteinemia but not homozygosity for MTHFR C677T polymorphism is a significant risk factor for DVT in the Iranian population. Also, MTHFR 677TT genotype is a determinant of elevated plasma tHcy levels. PMID:26719836

  12. Polymorphisms of 5,10-methylenetetrahydrofolate reductase and thymidylate synthase, dietary folate intake, and the risk of leukemia in adults.

    PubMed

    Liu, Ping; Zhang, Min; Xie, Xing; Jin, Jie; Holman, C D'Arcy J

    2016-03-01

    The 5,10-methylenetetrahydrofolate reductase (MTHFR) and thymidylate synthase (TS) are critical enzymes in folate metabolism. Previous studies have reported conflicting results on the associations between MTHFR/TS polymorphisms and adult leukemia risk, which may due to the lack of information on folate intake. We investigated the risks of adult leukemia with genetic polymorphisms of folate metabolic enzymes (MTHFR C677T, A1298C, and TS) and evaluated if the associations varied by dietary folate intake from a multicenter case-control study conducted in Chinese. This study comprised 442 incident adult leukemia cases and 442 outpatient controls, individually matched to cases by gender, birth quinquennium, and study site. Genotypes were determined by a polymerase chain reaction (PCR) or PCR-based restriction fragment length polymorphism assay. Dietary folate intake was assessed by face-to-face interviews using a validated food-frequency questionnaire. The MTHFR 677TT genotype conferred a significant higher risk of leukemia in males than in females and exhibited an increased risk of acute myeloid leukemia (AML) but a decreased risk of acute lymphoblastic leukemia (ALL). The MTHFR 1298AC genotype appeared to decrease the risks of leukemia in both genders, in AML and ALL. Stratified analysis by dietary folate intake showed the increased risks of leukemia with the MTHFR 677TT and TS 2R3R/2R2R genotypes were only significant in individuals with low folate intake. A significant interaction between TS polymorphism and dietary folate intake was observed (P = 0.03). This study suggests that dietary folate intake and gender may modify the associations between MTHFR/TS polymorphisms and adult leukemia risk. PMID:26438060

  13. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and fluorouracil-based treatment in Taiwan colorectal cancer.

    PubMed

    Wu, Nai-Chun; Su, Shih-Ming; Lin, Tai-Jung; Chin, Jen; Hou, Chun-Fang; Yang, Jhong-Ying; Liu, Wen-Sheng; Chang, Li-Ching

    2015-09-01

    This study aimed to investigate the association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and the prognosis of colorectal cancer (CRC) patients undergoing 5-fluorouracil (5-FU)-based chemotherapy in Taiwan. We investigated 126 CRC cases. The most common polymorphisms C677T (rs1801133) and A1298C (rs1801131) in MTHFR were genotyped using PCR-restriction fragment length polymorphism. The frequencies of C677T and A1298C were further compared with those in the HapMap database for Whites and Asians. In this study, we found that TT-homozygosity at MTHFR C677T was significantly associated with survival in CRC patients [P<0.001; 95% confidence interval (CI)=0.068-0.212]. In CRC patients receiving 5-FU-based chemotherapy, the TT genotype at C677T was also significantly associated with survival (P=0.001; 95% CI=0.113-0.400) and recurrence after surgery (P<0.001; 95% CI=0.295-0.609). The A1298C genotypes had a significant impact on survival (χ=7.103; P=0.029). The MTHFR A1298C CC genotype may increase the risk of death in Taiwanese CRC patients. The MTHFR C677T TT genotype was present at a lower frequency in our CRC patients than in the HapMap Asian population, but the frequency was similar to that in Whites in the HapMap database. The distribution of MTHFR A1298C genotypes was similar in our CRC and in the HapMap Asian population, but was different from that in the White population. This study suggested that MTHFR C677T and A1298C are associated with prognosis in CRC patients undergoing 5-FU-based chemotherapy. PMID:26111049

  14. The maize brown midrib2 (bm2) gene encodes a methylenetetrahydrofolate reductase that contributes to lignin accumulation

    PubMed Central

    Tang, Ho Man; Liu, Sanzhen; Hill-Skinner, Sarah; Wu, Wei; Reed, Danielle; Yeh, Cheng-Ting; Nettleton, Dan; Schnable, Patrick S

    2014-01-01

    The midribs of maize brown midrib (bm) mutants exhibit a reddish-brown color associated with reductions in lignin concentration and alterations in lignin composition. Here, we report the mapping, cloning, and functional and biochemical analyses of the bm2 gene. The bm2 gene was mapped to a small region of chromosome 1 that contains a putative methylenetetrahydrofolate reductase (MTHFR) gene, which is down-regulated in bm2 mutant plants. Analyses of multiple Mu-induced bm2-Mu mutant alleles confirmed that this constitutively expressed gene is bm2. Yeast complementation experiments and a previously published biochemical characterization show that the bm2 gene encodes a functional MTHFR. Quantitative RT-PCR analyses demonstrated that the bm2 mutants accumulate substantially reduced levels of bm2 transcript. Alteration of MTHFR function is expected to influence accumulation of the methyl donor S-adenosyl-l-methionine (SAM). Because SAM is consumed by two methyltransferases in the lignin pathway (Ye et al., 1994), the finding that bm2 encodes a functional MTHFR is consistent with its lignin phenotype. Consistent with this functional assignment of bm2, the expression patterns of genes in a variety of SAM-dependent or -related pathways, including lignin biosynthesis, are altered in the bm2 mutant. Biochemical assays confirmed that bm2 mutants accumulate reduced levels of lignin with altered composition compared to wild-type. Hence, this study demonstrates a role for MTHFR in lignin biosynthesis. PMID:24286468

  15. Genotype and haplotype distributions of MTHFR677C>T and 1298A>C single nucleotide polymorphisms: a meta-analysis.

    PubMed

    Ogino, Shuji; Wilson, Robert B

    2003-01-01

    Common single nucleotide polymorphisms (SNPs; 677C>T and 1298A>C) in the methylenetetrahydrofolate reductase gene ( MTHFR) decrease the activity of the enzyme, leading to hyperhomocysteinemia, particularly in folate-deficient states. We calculate herein the haplotype frequencies of the MTHFR 677 and 1298 polymorphisms in pooled general populations derived from published data. We selected 16 articles that provided reliable data on combined MTHFR genotypes in general populations ( n = 5389). The combined data comprised the following totals for each genotype at nucleotide positions 677 and 1298: 838 CC/AA (i.e., 677CC/1298AA), 1225 CC/AC, 489 CC/CC, 1120 CT/AA, 1093 CT/AC, 8 CT/CC, 606 TT/AA, 10 TT/AC, and 0 TT/CC. The estimated haplotype frequencies, and the fractional contribution of each, were 677C/1298A, 0.37; 677C/1298C, 0.31; 677T/1298A, 0.32; and 677T/1298C, 0.0023 to 0.0034. Thus, a vast majority of 677T alleles and 1298C alleles are associated with 1298A alleles and 677C alleles, respectively. There may be an increased frequency of the very rare cis 677T/1298C haplotype in some parts of the United Kingdom and Canada, possibly due to a founder effect. Further studies on both SNPs are needed to determine their exact role in various clinical settings. PMID:12560871

  16. MTHFR C677T and A1298C polymorphisms as predictors of radiotherapy response in head and neck squamous cell carcinoma.

    PubMed

    Anders, Q S; Stur, E; Agostini, L P; Garcia, F M; Reis, R S; Santos, J A; Mendes, S O; Maia, L L; Peterle, G T; Stange, V; Carvalho, M B; Tajara, E H; Santos, M; Silva-Conforti, A M A; Louro, I D

    2015-01-01

    The C677T and A1298C polymorphisms in methylene-tetrahydrofolate reductase (MTHFR), which regulates the release of active folate in the body, may have reduced activity. Given that folate participates in important intracellular pathways, such as nucleotide synthesis and biomolecule methylation, it seems plausible that patients with head and neck squamous cell carcinoma (HNSCC) may respond differently to radiotherapy treatments, based on genetic polymor-phisms. Therefore, this study sought to understand the role of these polymorphisms in HNSCC patient radiotherapy response. Genotypes were detected by PCR-RFLP after extraction of DNA from peripheral blood lymphocytes. Survival curves were analyzed by the Kaplan- Meier model, and significant differences were analyzed by the Wil-coxon test. Response to radiotherapy in patients with laryngeal SCC was significantly associated with the MTHFR C677T polymorphism (P = 0.030). Indeed, the presence of at least one T allele decreases the mortality rate up to 3-fold. Therefore, we propose that MTHFR C677T may represent a putative biomarker for radiotherapy prognosis in la-ryngeal SCC patients. PMID:26535623

  17. Effects of folic acid deficiency and MTHFR C677T polymorphism on spontaneous and radiation-induced micronuclei in human lymphocytes.

    PubMed

    Leopardi, Paola; Marcon, Francesca; Caiola, Stefania; Cafolla, Arturo; Siniscalchi, Ester; Zijno, Andrea; Crebelli, Riccardo

    2006-09-01

    Folic acid plays a key role in the maintenance of genomic stability, providing methyl groups for the conversion of uracil to thymine and for DNA methylation. Besides dietary habits, folic acid metabolism is influenced by genetic polymorphism. The C677T polymorphism of the methylene-tetrahydrofolate reductase (MTHFR) gene is associated with a reduction of catalytic activity and is suggested to modify cancer risk differently depending on folate status. In this work the effect of folic acid deficiency on genome stability and radiosensitivity has been investigated in cultured lymphocytes of 12 subjects with different MTHFR genotype (four for each genotype). Cells were grown for 9 days with 12, 24 and 120 nM folic acid and analyzed in a comprehensive micronucleus test coupled with centromere characterization by CREST immunostaining. In other experiments, cells were grown with various folic acid concentrations, irradiated with 0.5 Gy of gamma rays and analyzed in the micronucleus test. The results obtained indicate that folic acid deficiency induces to a comparable extent chromosome loss and breakage, irrespective of the MTHFR genotype. The effect of folic acid was highly significant (P < 0.001) and explained >50% of variance of both types of micronuclei. Also nucleoplasmic bridges and buds were significantly increased under low folate supply; the increase in bridges was mainly observed in TT cells, highlighting a significant effect of the MTHFR genotype (P = 0.006) on this biomarker. Folic acid concentration significantly affected radiation-induced micronuclei (P < 0.001): the increased incidence of radiation-induced micronuclei with low folic acid was mainly accounted for by carriers of the variant MTHFR allele (both homozygotes and heterozygotes), but the overall effect of genotype did not attain statistical significance. Treatment with ionizing radiations also increased the frequency of nucleoplasmic bridges. The effect of folic acid level on this end-point was

  18. Association between the MTHFR C677T polymorphism and gastric cancer susceptibility: A meta-analysis of 5,757 cases and 8,501 controls

    PubMed Central

    CHEN, LONG; LU, NING; ZHANG, BAI-HONG; WENG, LI; LU, JUN

    2015-01-01

    Current data regarding the association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and the risk of developing gastric cancer are insufficient to draw definite conclusions. Therefore, the present meta-analysis was conducted to achieve a more precise estimation of the association. MEDLINE, EMBASE and Wanfang database searches resulted in the identification of 28 eligible studies describing 5,757 cases and 8,501 controls. The strength of the association between the MTHFR C677T polymorphism and gastric cancer risk were evaluated using crude odds ratios (ORs), with 95% confidence intervals (CIs). The pooled ORs were determined using homozygous (TT vs. CC), heterozygous (CT vs. CC), dominant (TT+CT vs. CC) and recessive (TT vs. CC+CT) models. When all studies were pooled into the meta-analysis, significant associations were identified between the MTHFR C677T polymorphism and the risk of gastric cancer (homozygous model: OR, 1.39; 95% CI, 1.20–1.62; heterozygous model: OR, 1.18; 95% CI, 1.05–1.32; dominant model: OR, 1.23; 95% CI, 1.10–1.38; recessive model: OR, 1.26; 95% CI, 1.12–1.42). Stratification of the data by ethnicity identified a statistically significantly elevated risk of gastric cancer in Asian MTHFR C677T polymorphism populations (homozygous model: OR, 1.64; 95% CI, 1.43–1.90; heterozygous model: OR, 1.30; 95% CI, 1.16–1.45; dominant model: OR, 1.39; 95% CI, 1.25–1.54; recessive model: OR, 1.41; 95% CI, 1.25–1.51), but not in Caucasian populations (homozygous model: OR, 1.15; 95% CI, 0.89–1.48; heterozygous model: OR, 1.03; 95% CI, 0.84–1.25; dominant model: OR, 1.05; 95% CI, 0.86–1.28; recessive model: OR, 1.09; 95% CI, 0.91–1.31). Following adjustment for heterogeneity, the current meta-analysis demonstrated that the MTHFR C677T polymorphism was not associated with the risk of gastric cancer in Caucasian individuals. Furthermore, no evidence of publication bias was observed. Thus, the current meta

  19. Role of genetic mutations in folate-related enzyme genes on Male Infertility

    PubMed Central

    Liu, Kang; Zhao, Ruizhe; Shen, Min; Ye, Jiaxin; Li, Xiao; Huang, Yuan; Hua, Lixin; Wang, Zengjun; Li, Jie

    2015-01-01

    Several studies showed that the genetic mutations in the folate-related enzyme genes might be associated with male infertility; however, the results were still inconsistent. We performed a meta-analysis with trial sequential analysis to investigate the associations between the MTHFR C677T, MTHFR A1298C, MTR A2756G, MTRR A66G mutations and the MTHFR haplotype with the risk of male infertility. Overall, a total of 37 studies were selected. Our meta-analysis showed that the MTHFR C677T mutation was a risk factor for male infertility in both azoospermia and oligoasthenoteratozoospermia patients, especially in Asian population. Men carrying the MTHFR TC haplotype were most liable to suffer infertility while those with CC haplotype had lowest risk. On the other hand, the MTHFR A1298C mutation was not related to male infertility. MTR A2756G and MTRR A66G were potential candidates in the pathogenesis of male infertility, but more case-control studies were required to avoid false-positive outcomes. All of these results were confirmed by the trial sequential analysis. Finally, our meta-analysis with trial sequential analysis proved that the genetic mutations in the folate-related enzyme genes played a significant role in male infertility. PMID:26549413

  20. Role of genetic mutations in folate-related enzyme genes on Male Infertility.

    PubMed

    Liu, Kang; Zhao, Ruizhe; Shen, Min; Ye, Jiaxin; Li, Xiao; Huang, Yuan; Hua, Lixin; Wang, Zengjun; Li, Jie

    2015-01-01

    Several studies showed that the genetic mutations in the folate-related enzyme genes might be associated with male infertility; however, the results were still inconsistent. We performed a meta-analysis with trial sequential analysis to investigate the associations between the MTHFR C677T, MTHFR A1298C, MTR A2756G, MTRR A66G mutations and the MTHFR haplotype with the risk of male infertility. Overall, a total of 37 studies were selected. Our meta-analysis showed that the MTHFR C677T mutation was a risk factor for male infertility in both azoospermia and oligoasthenoteratozoospermia patients, especially in Asian population. Men carrying the MTHFR TC haplotype were most liable to suffer infertility while those with CC haplotype had lowest risk. On the other hand, the MTHFR A1298C mutation was not related to male infertility. MTR A2756G and MTRR A66G were potential candidates in the pathogenesis of male infertility, but more case-control studies were required to avoid false-positive outcomes. All of these results were confirmed by the trial sequential analysis. Finally, our meta-analysis with trial sequential analysis proved that the genetic mutations in the folate-related enzyme genes played a significant role in male infertility. PMID:26549413

  1. Interactions of Methylenetetrahydrofolate Reductase C677T Polymorphism with Environmental Factors on Hypertension Susceptibility

    PubMed Central

    Fan, Shujun; Yang, Boyi; Zhi, Xueyuan; Wang, Yanxun; Wei, Jian; Zheng, Quanmei; Sun, Guifan

    2016-01-01

    Hypertension is considered to be the result of genes, environment, and their interactions. Among them age, sex, tobacco use, alcohol consumption, and being overweight/obesity are well documented environmental determinants, and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is nominated as a potential genetic candidate. However, the synergistic effect of the MTHFR C677T polymorphism with these environmental factors on the risk of hypertension has received little attention. The aim of this study was to explore the associations of the MTHFR C677T polymorphism, environmental factors, and their interactions with hypertension predisposition in a Northern Chinese Han population. A total of 708 participants were enrolled in the study. The genotypes of the MTHFR C677T were determined by a TaqMan assay. We found that participants of an older age, being overweight/obesity, with a smoking habit, drinking habit, or carrying the 677T allele were at an increased risk of hypertension. Additionally, there existed marginally significant interactions of the polymorphism with age and overweight/obesity. However, future large, well-designed studies in Chinese and other populations, as well as mechanistic studies, are still needed to validate our findings, especially considering that the interactions observed in our study were only marginally significant. PMID:27322299

  2. Folate Pathway Gene Methylenetetrahydrofolate Reductase C677T Polymorphism and Alzheimer Disease Risk in Asian Population.

    PubMed

    Rai, Vandana

    2016-07-01

    The association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and susceptibility to Alzheimers disease (AD) was controversial in previous studies. The present meta-analysis was designed to investigate the association of MTHFR C677T polymorphism with AD. Nine studies were identified by search of PubMed, Google Scholar, Elsevier, Springer Link databases, up to January 2013. Odds ratios (ORs) with corresponding 95 % confidence interval (CI) were calculated using fixed effects model or random effects model. All statistical analysis was done by Mix version 1.7. MTHFR C677T polymorphism had a significant association with susceptibility to AD in all genetic models (for T vs C: OR 1.29, 95 % CI 1.15-1.44, p < 0.0001; for TT + CT vs CC: OR 1.38, 95 % CI 1.16-1.364, p = 0.0002; for TT vs CC: OR 1.60, 95 % CI 1.25-2.04, p = 0.0001; for CT vs CC: OR 1.28, 95 % CI 1.1-1.53, p < 0.008; for TT vs CT + CC: OR 1.37, 95 % CI 1.12-1.67, p = 0.002). Results from present meta-analysis supported that the MTHFR C677T polymorphism was associated with an increased risk of AD in Asian population. PMID:27382194

  3. Interactions of Methylenetetrahydrofolate Reductase C677T Polymorphism with Environmental Factors on Hypertension Susceptibility.

    PubMed

    Fan, Shujun; Yang, Boyi; Zhi, Xueyuan; Wang, Yanxun; Wei, Jian; Zheng, Quanmei; Sun, Guifan

    2016-01-01

    Hypertension is considered to be the result of genes, environment, and their interactions. Among them age, sex, tobacco use, alcohol consumption, and being overweight/obesity are well documented environmental determinants, and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is nominated as a potential genetic candidate. However, the synergistic effect of the MTHFR C677T polymorphism with these environmental factors on the risk of hypertension has received little attention. The aim of this study was to explore the associations of the MTHFR C677T polymorphism, environmental factors, and their interactions with hypertension predisposition in a Northern Chinese Han population. A total of 708 participants were enrolled in the study. The genotypes of the MTHFR C677T were determined by a TaqMan assay. We found that participants of an older age, being overweight/obesity, with a smoking habit, drinking habit, or carrying the 677T allele were at an increased risk of hypertension. Additionally, there existed marginally significant interactions of the polymorphism with age and overweight/obesity. However, future large, well-designed studies in Chinese and other populations, as well as mechanistic studies, are still needed to validate our findings, especially considering that the interactions observed in our study were only marginally significant. PMID:27322299

  4. Coronary reactivity, homocysteine and methylenetetrahydrofolate reductase gene variation in young men during pravastatin therapy.

    PubMed

    Nieminen, Tuomo; Knuuti, Juhani; Hämelahti, Päivi; Kähönen, Mika; Laaksonen, Reijo; Janatuinen, Tuula; Vesalainen, Risto; Nuutila, Pirjo; Jokela, Hannu; Lehtimäki, Terho

    2007-01-01

    High plasma homocysteine (Hcy) has been linked to impaired endothelial function. We investigated whether treatment with pravastatin affects the Hcy levels. Moreover, we studied whether the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism affects coronary vasomotion at baseline and during the treatment with pravastatin. Fifty-one healthy, mildly hypercholesterolemic men (mean age 35+/-4 years) attended this randomised, double-blind, placebo-controlled study. The volunteers were randomised into groups with 6-month treatment with pravastatin (40 mg/day, n=25) or placebo (n=26). Coronary blood flow measurements with positron emission tomography at rest and during adenosine infusion as well as biochemical analyses were done at baseline and at the end of the treatment period. The Hcy concentration decreased significantly during the pravastatin therapy (-0.81+/-1.46 micromol/l, p=0.01), but not during placebo (0.02+/-2.39 micromol/l, p=0.97). The MTHFR polymorphism did not affect the Hcy concentration or coronary flow indices. Neither did the MTHFR polymorphism modulate the effects of pravastatin on coronary vasomotion. In conclusion, a 6-month therapy with pravastatin decreases Hcy concentration in Finnish healthy young men. The MTHFR genotype is neither a determinant of baseline coronary flow indices nor does it modulate the effect of pravastatin on coronary reactivity. PMID:17574929

  5. Aberrant DNA Methylation of P16, MGMT, and hMLH1 Genes in Combination with MTHFR C677T Genetic Polymorphism in gastric cancer

    PubMed Central

    Song, Binbin; Ai, Jiang; Kong, Xianghong; Liu, Dexin; Li, Jun

    2013-01-01

    Objective: We aimed to explore the association of P16, MGMT and HMLH1 with gastric cancer and their relation with Methylenetetrahydrofolate reductase (MTHFR). Methods: 322 gastric patients who were confirmed with pathological diagnosis were included in our study. Aberrant DNA methylation of P16, MGMT and HMLH1 and polymorphisms of MTHFR C677T and A1298C were detected using PCR-RFLP. Results: The proportions of DNA hypermethylation in P16, MGMT and hMLH1 genes in gastric cancer tissues were 75.2% (242/322), 27.6% (89/322) and 5.3% (17/322), respectively. In the remote normal-appearing tissues, 29.5% (95/322) and 16.1%(52/322) showed hypermethylation in P16 and MGMT genes, respectively. We found a significantly higher proportion of DNA hypermethylation of P16 in patients with N1 TNM stage in cancer tissues and remote normal-appearing tissues (P<0.05). Similarly, we found DNA hypermethylation of MGMT had significantly higher proportion in N1 and M1 TNM stage (P<0.05). Individuals with homozygotes (TT) of MTHFR C677T had significant risk of DNA hypermethylation of MGMT in cancer tissues [OR (95% CI)=4.27(1.76-7.84)], and a significant risk was also found in those carrying MTHFR 677CT/TT genotype [OR (95% CI)= 3.27(1.21-4.77)]. Conclusion: We found the aberrant hypermethylation of cancer-related genes, such as P16, MGMT and HMLH1, could be predictive biomarkers for detection of gastric cancer. PMID:24550949

  6. A Single Nucleotide Polymorphism in the MTHFR Gene is Associated with Risk of Radiation Pneumonitis in Lung Cancer Patients Treated with Thoracic Radiation Therapy

    PubMed Central

    Mak, Raymond H.; Alexander, Brian M.; Asomaning, Kofi; Heist, Rebecca S.; Liu, Chen-yu; Su, Li; Zhai, Rihong; Ancukiewicz, Marek; Napolitano, Brian; Niemierko, Andrzej; Willers, Henning; Choi, Noah C.; Christiani, David C.

    2011-01-01

    Background To study the association between functional single nucleotide polymorphisms (SNPs) in candidate genes from oxidative stress pathways, and risk of radiation pneumonitis (RP) in patients treated with thoracic radiation therapy (RT) for locally advanced lung cancer (LC). Methods We reviewed 136 patients treated with RT for LC between 2001 and 2007, and had prior genotyping of functional SNPs in oxidative stress genes including superoxide dismutase 2 (SOD2; rs4880) and methylenetetrahydrofolate reductase (MTHFR; rs1801131, rs1801133). RP events were retrospectively scored using the Common Terminology Criteria for Adverse Events, version 4.0. Cox proportional hazard regression was performed to identify clinical variables and genotypes associated with risk of grade ≥2 and grade ≥3 RP on univariate and multivariate analysis. P-values were corrected for multiple hypothesis testing. Results With a median follow-up of 21.4 months, the incidence of ≥grade 2 RP was 29% and ≥grade 3 RP was 14%. On multivariate analysis, after adjusting for clinical factors such as concurrent chemotherapy, and consolidation docetaxel, and lung dosimetric parameters such as V20 and mean lung dose, MTHFR genotype (rs1801131; AA versus AC/CC) was significantly associated with risk of ≥grade 2 RP (Hazard ratio [HR]: 0.37; 95% confidence interval [CI]: 0.18-0.76; p=0.006, corrected p=0.018) and ≥grade 3 RP (HR: 0.21; 95% CI: 0.06-0.70; p=0.01; corrected p=0.03). SOD2 genotype was not associated with RP. Conclusions Our study showed an association between MTHFR genotype and risk of clinically significant RP. Further study of MTHFR-related pathways may provide insight into the mechanisms behind RP. PMID:22144047

  7. Haplotypes of the MTHFR gene are associated with an increased risk of breast cancer in a Han Chinese population in Gansu province.

    PubMed

    Song, Ailing; Zhao, Lei; Li, Yumin; Wu, Li; Li, Yu; Liu, Xiaokang; Lan, Shen

    2016-07-01

    Elevated homocysteine levels are a risk factor for breast cancer, although the mechanism underlying this effect is unknown. Genome-wide association studies were used to systematically identify genetic variants which were significantly associated with the circulating homocysteine concentration. To examine the role of homocysteine-related variants in the occurrence of breast cancer, we investigated the association between these variants and breast cancer in a Han Chinese population. Five variants of genome-wide significant homocysteine-related genes were selected for the analysis in a case-control study, with a total of 487 patients with breast cancer and 605 controls. We found that none of the studied polymorphisms were related to the altered breast cancer risk. In the haplotypic analysis, the 5,10-methylenetetrahydrofolate reductase (MTHFR) haplotypes rs12085006A/rs1999594G/rs1801133C (OR = 3.44, 95% CI = 1.58-7.50, P = 0.0019) and rs12085006A/rs1999594G/rs1801133T (OR = 16.21, 95% CI = 2.19- 120.32, P = 0.0065) were significantly associated with an increased breast cancer risk when compared with the wild-type haplotype. Both of the risky MTHFR haplotypes were correlated with decreased MTHFR gene expression and elevated homocysteine concentrations, indicating a genetic component for hyperhomocysteinemia. The MTHFR haplotypes reconstructed with homocysteine-related variants were associated with the occurrence of breast cancer. This finding further emphasizes the importance of homocysteine metabolism genes in breast carcinogenesis and highlights the interplay of diet, genetics, and human cancers. © 2016 IUBMB Life, 68(7):526-534, 2016. PMID:27237471

  8. Sex Differences in Ethanol’s Anxiolytic Effect and Chronic Ethanol Withdrawal Severity in Mice With a Null Mutation of the 5α-Reductase Type 1 Gene

    PubMed Central

    Tanchuck-Nipper, Michelle A.; Ford, Matthew M.; Hertzberg, Anna; Beadles-Bohling, Amy; Cozzoli, Debra K.; Finn, Deborah A.

    2015-01-01

    Manipulation of endogenous levels of the GABAergic neurosteroid allopregnanolone alters sensitivity to some effects of ethanol. Chronic ethanol withdrawal decreases activity and expression of 5α-reductase-1, an important enzyme in allopregnanolone biosynthesis encoded by the 5α-reductase-1 gene (Srd5a1). The present studies examined the impact of Srd5a1 deletion in male and female mice on several acute effects of ethanol and on chronic ethanol withdrawal severity. Genotype and sex did not differentially alter ethanol-induced hypothermia, ataxia, hypnosis, or metabolism, but ethanol withdrawal was significantly lower in female versus male mice. On the elevated plus maze, deletion of the Srd5a1 gene significantly decreased ethanol’s effect on total entries versus wildtype (WT) mice and significantly decreased ethanol’s anxiolytic effect in female knockout (KO) versus WT mice. The limited sex differences in the ability of Srd5a1 genotype to modulate select ethanol effects may reflect an interaction between developmental compensations to deletion of the Srd5a1 gene with sex hormones and levels of endogenous neurosteroids. PMID:25355320

  9. New insights into the catalytic mechanism of vitamin K epoxide reductase (VKORC1) – The catalytic properties of the major mutations of rVKORC1 explain the biological cost associated to mutations☆

    PubMed Central

    Matagrin, Benjamin; Hodroge, Ahmed; Montagut-Romans, Adrien; Andru, Julie; Fourel, Isabelle; Besse, Stéphane; Benoit, Etienne; Lattard, Virginie

    2013-01-01

    The systematic use of antivitamin K anticoagulants (AVK) as rodenticides caused the selection of rats resistant to AVKs. The resistance is mainly associated to genetic polymorphisms in the Vkorc1 gene encoding the VKORC1 enzyme responsible for the reduction of vitamin K 2,3-epoxide to vitamin K. Five major mutations, which are responsible for AVK resistance, have been described. Possible explanations for the biological cost of these mutations have been suggested. This biological cost might be linked to an increase in the vitamin K requirements. To analyze the possible involvement of VKORC1 in this biological cost, rVKORC1 and its major mutants were expressed in Pichia pastoris as membrane-bound proteins and their catalytic properties were determined for vitamin K and 3-OH-vitamin K production. In this report, we showed that mutations at Leu-120 and Tyr-139 dramatically affect the vitamin K epoxide reductase activity. Moreover, this study allowed the detection of an additional production of 3-hydroxyvitamin K for all the mutants in position 139. This result suggests the involvement of Tyr-139 residue in the second half-step of the catalytic mechanism corresponding to the dehydration of vitamin K epoxide. As a consequence, the biological cost observed in Y139C and Y139S resistant rat strains is at least partially explained by the catalytic properties of the mutated VKORC1 involving a loss of vitamin K from the vitamin K cycle through the formation of 3-hydroxyvitamin K and a very low catalytic efficiency of the VKOR activity. PMID:23772386

  10. Relationship of the 1793G-A and 677C-T polymorphisms of the 5,10-methylenetetrahydrofolate reductase gene to coronary artery disease.

    PubMed

    Kebert, Cory B; Eichner, June E; Moore, William E; Schechter, Eliot; Yaoi, Takuro; Vogel, Steve; Allen, Richard A; Dunn, S Terence

    2006-01-01

    Numerous studies have investigated the relationship between polymorphisms, in particular 677C-T and 1298A-C, of the methylene-tetrahydrofolate reductase (MTHFR) gene and coronary artery disease (CAD) with conflicting results. This study investigates the potential association of two point mutations in MTHFR, 677C-T and 1793G-A, along with other risk factors, with CAD. This is the first hospital-based study to investigate 1793G-A in this context. Genotype analysis was performed on 729 Caucasians and 66 African Americans undergoing coronary angiography using a novel PCR-based assay involving formation of Holliday junctions. Allelic frequencies for 677C-T were 66.2% C and 33.8% T for Caucasians and 90.9% C and 9.1% T for African Americans. With respect to the 1793G-A polymorphism, allelic frequencies were 94.7% G and 5.3% A for Caucasians and 99.2% G and 0.8% A for African Americans. Disease associations were examined in the Caucasian patients due to their greater genotype variability and larger number in the patient cohort. Results suggest that neither 677CT heterozygotes (OR-1.36; 95% CI 0.95 to 1.96) nor mutant homozygotes (OR-0.73; 95% CI 0.44 to 1.20) have either an increased or decreased risk for CAD compared to the 677CC genotype. Likewise, the 1793GA genotype did not demonstrate a statistically significant association with CAD compared to 1793GG patients (OR-0.79; 95% CI 0.47 to 1.33). Mean homocysteine levels (mumol/L) increased from normal to mutant for 677C-T (677CC: 10.2; 677CT: 11.0; 677TT: 11.6) and normal to heterozygous in 1793G-A (1793GG: 10.7; 1793GA: 11.5). These MTHFR polymorphisms did not contribute to the prediction of clinically defined CAD in Caucasians. PMID:17264399

  11. Relationship of the 1793G-A and 677C-T Polymorphisms of the 5,10-Methylenetetrahydrofolate Reductase Gene to Coronary Artery Disease

    PubMed Central

    Kebert, Cory B.; Eichner, June E.; Moore, William E.; Schechter, Eliot; Yaoi, Takuro; Vogel, Steve; Allen, Richard A.; Dunn, S. Terence

    2006-01-01

    Numerous studies have investigated the relationship between polymorphisms, in particular 677C-T and 1298A-C, of the methylene-tetrahydrofolate reductase (MTHFR) gene and coronary artery disease (CAD) with conflicting results. This study investigates the potential association of two point mutations in MTHFR, 677C-T and 1793G-A, along with other risk factors, with CAD. This is the first hospital-based study to investigate 1793G-A in this context. Genotype analysis was performed on 729 Caucasians and 66 African Americans undergoing coronary angiography using a novel PCR-based assay involving formation of Holliday junctions. Allelic frequencies for 677C-T were 66.2% C and 33.8% T for Caucasians and 90.9% C and 9.1% T for African Americans. With respect to the 1793G-A polymorphism, allelic frequencies were 94.7% G and 5.3% A for Caucasians and 99.2% G and 0.8% A for African Americans. Disease associations were examined in the Caucasian patients due to their greater genotype variability and larger number in the patient cohort. Results suggest that neither 677CT heterozygotes (OR-1.36; 95% CI 0.95 to 1.96) nor mutant homozygotes (OR-0.73; 95% CI 0.44 to 1.20) have either an increased or decreased risk for CAD compared to the 677CC genotype. Likewise, the 1793GA genotype did not demonstrate a statistically significant association with CAD compared to 1793GG patients (OR-0.79; 95% CI 0.47 to 1.33). Mean homocysteine levels (μmol/L) increased from normal to mutant for 677C-T (677CC: 10.2; 677CT: 11.0; 677TT: 11.6) and normal to heterozygous in 1793G-A (1793GG: 10.7; 1793GA: 11.5). These MTHFR polymorphisms did not contribute to the prediction of clinically defined CAD in Caucasians. PMID:17264399

  12. Incidence Assessment of MTHFR C677T and A1298C Polymorphisms in Iranian Non-syndromic Cleft Lip and/or Palate Patients.

    PubMed

    Ebadifar, Asghar; Ameli, Nazila; Khorramkhorshid, Hamid Reza; Salehi Zeinabadi4, Mehdi; Kamali, Kourosh; Khoshbakht, Tayyebeh

    2015-01-01

    Background and aims. The aim of the present study is to determine the incidence of MTHFR C677 T and A1298C muta-tions in Iranian patients with cleft lip and/or cleft palate. Materials and methods. We screened 61 Iranian patients with cleft lip and/or cleft palate for mutations in the two alleles of MTHFR gene associated with cleft lip and/or palate: A1298C and C677T, using Polymerase Chain Reaction following by RFLP. Results. The 677T and 1298C homozygote genotypes showed a frequency of 36.1% and 11.4%, respectively. Combined genotype frequencies in newborns having oral clefts showed that the highest genotype was 677TT/1298AA (22.9%) and 677TT/1298CC genotypes were not observed. Conclusion. The results showed that 65.6% of all patients had at least one T mutant allele in C677T and 58.9% C mutant allele for A1298C. According to the frequencies of homozygosity of mutant alleles, it could be said that MTHFR genotype of 677TT shows a greater role in having oral clefts. PMID:26236436

  13. Incidence Assessment of MTHFR C677T and A1298C Polymorphisms in Iranian Non-syndromic Cleft Lip and/or Palate Patients

    PubMed Central

    Ebadifar, Asghar; Ameli, Nazila; Khorramkhorshid, Hamid Reza; Salehi Zeinabadi4, Mehdi; Kamali, Kourosh; Khoshbakht, Tayyebeh

    2015-01-01

    Background and aims. The aim of the present study is to determine the incidence of MTHFR C677 T and A1298C muta-tions in Iranian patients with cleft lip and/or cleft palate. Materials and methods. We screened 61 Iranian patients with cleft lip and/or cleft palate for mutations in the two alleles of MTHFR gene associated with cleft lip and/or palate: A1298C and C677T, using Polymerase Chain Reaction following by RFLP. Results. The 677T and 1298C homozygote genotypes showed a frequency of 36.1% and 11.4%, respectively. Combined genotype frequencies in newborns having oral clefts showed that the highest genotype was 677TT/1298AA (22.9%) and 677TT/1298CC genotypes were not observed. Conclusion. The results showed that 65.6% of all patients had at least one T mutant allele in C677T and 58.9% C mutant allele for A1298C. According to the frequencies of homozygosity of mutant alleles, it could be said that MTHFR genotype of 677TT shows a greater role in having oral clefts. PMID:26236436

  14. Conversion of Human Steroid 5[beta]-Reductase (AKR1D1) into 3[beta]-Hydroxysteroid Dehydrogenase by Single Point Mutation E120H: Example of Perfect Enzyme Engineering

    SciTech Connect

    Chen, Mo; Drury, Jason E.; Christianson, David W.; Penning, Trevor M.

    2012-10-10

    Human aldo-keto reductase 1D1 (AKR1D1) and AKR1C enzymes are essential for bile acid biosynthesis and steroid hormone metabolism. AKR1D1 catalyzes the 5{beta}-reduction of {Delta}{sup 4}-3-ketosteroids, whereas AKR1C enzymes are hydroxysteroid dehydrogenases (HSDs). These enzymes share high sequence identity and catalyze 4-pro-(R)-hydride transfer from NADPH to an electrophilic carbon but differ in that one residue in the conserved AKR catalytic tetrad, His120 (AKR1D1 numbering), is substituted by a glutamate in AKR1D1. We find that the AKR1D1 E120H mutant abolishes 5{beta}-reductase activity and introduces HSD activity. However, the E120H mutant unexpectedly favors dihydrosteroids with the 5{alpha}-configuration and, unlike most of the AKR1C enzymes, shows a dominant stereochemical preference to act as a 3{beta}-HSD as opposed to a 3{alpha}-HSD. The catalytic efficiency achieved for 3{beta}-HSD activity is higher than that observed for any AKR to date. High resolution crystal structures of the E120H mutant in complex with epiandrosterone, 5{beta}-dihydrotestosterone, and {Delta}{sup 4}-androstene-3,17-dione elucidated the structural basis for this functional change. The glutamate-histidine substitution prevents a 3-ketosteroid from penetrating the active site so that hydride transfer is directed toward the C3 carbonyl group rather than the {Delta}{sup 4}-double bond and confers 3{beta}-HSD activity on the 5{beta}-reductase. Structures indicate that stereospecificity of HSD activity is achieved because the steroid flips over to present its {alpha}-face to the A-face of NADPH. This is in contrast to the AKR1C enzymes, which can invert stereochemistry when the steroid swings across the binding pocket. These studies show how a single point mutation in AKR1D1 can introduce HSD activity with unexpected configurational and stereochemical preference.

  15. The association between MTHFR 677C>T genotype and folate status and genomic and gene-specific DNA methylation in the colon of individuals without colorectal neoplasia1234

    PubMed Central

    Hanks, Joanna; Ayed, Iyeman; Kukreja, Neil; Rogers, Chris; Harris, Jessica; Gheorghiu, Alina; Liu, Chee Ling; Emery, Peter

    2013-01-01

    Background: Decreased genomic and increased gene-specific DNA methylation predispose to colorectal cancer. Dietary folate intake and the methylenetetrahydrofolate reductase polymorphism (MTHFR 677C>T) may influence risk by modifying DNA methylation. Objective: We investigated the associations between MTHFR 677C>T genotype, folate status, and DNA methylation in the colon. Design: We conducted a cross-sectional study of 336 men and women (age 19–92 y) in the United Kingdom without colorectal neoplasia. We obtained blood samples for measurement of serum and red blood cell folate, plasma homocysteine, and MTHFR 677C>T genotype and colonic tissue biopsies for measurement of colonic tissue folate and DNA methylation (genomic- and gene-specific, estrogen receptor 1, ESR1; myoblast determination protein 1, MYOD1; insulin-like growth factor II, IGF2; tumor suppressor candidate 33, N33; adenomatous polyposis coli, APC; mut-L homolog 1, MLH1; and O6-methylguanine-DNA methyltransferase, MGMT) by liquid chromatography/electrospray ionization mass spectrometry and pyrosequencing, respectively. Results: Of the 336 subjects recruited, 185 (55%) carried the CC, 119 (35%) the CT, and 32 (10%) the TT alleles. No significant differences in systemic markers of folate status and colonic tissue folate between genotypes were found. The MTHFR TT genotype was not associated with genomic or gene-specific DNA methylation. Biomarkers of folate status were not associated with genomic DNA methylation. Relations between biomarkers of folate status and gene-specific methylation were inconsistent. However, low serum folate was associated with high MGMT methylation (P = 0.001). Conclusion: MTHFR 677C>T genotype and folate status were generally not associated with DNA methylation in the colon of a folate-replete population without neoplasia. This trial was registered at clinicaltrials.gov as ISRCTN43577261. PMID:24108782

  16. Controversial roles of methylenetetrahydrofolate reductase polymorphisms and folate in breast cancer disease.

    PubMed

    Bravatà, Valentina

    2015-02-01

    Breast cancer (BC) represents a highly heterogeneous tumour at both the clinical and molecular levels. Single-nucleotide polymorphisms (SNPs) of the folate-metabolising enzyme methylenetetrahydrofolate-reductase (MTHFR) may modify the association between folate intake and BC and influence plasma folate concentration. The role of folate in BC is equivocal, association studies between the common MTHFR SNPs C677T and A1298C and BC risk are controversial. In this study, I have reviewed observed associations between folate intake, as well as its blood levels, and BC. The purpose of this review is to analyse the role of folate and the two SNPs associated with reduced enzyme activity in BC. I explored the most relevant and updated work that emphasises positive and negative associations among these variables. My findings indicate that no definitive conclusions can be drawn from the studies on this topic. However, this manuscript highlights variables that could be useful to explore in further association analyses. PMID:25318348

  17. Association of Blood Lead Levels with Methylenetetrahydrofolate Reductase Polymorphisms among Chinese Pregnant Women in Wuhan City

    PubMed Central

    Shen, Wei; Zhang, Bin; Liu, Shuyun; Wu, Hongling; Gu, Xue; Qin, Lingzhi; Tian, Ping; Zeng, Yun; Ye, Linxiang; Ni, Zemin; Wang, Qi

    2015-01-01

    Background Pregnancy is an important stimulus of bone lead release. Elevated blood lead levels (BLLs) may cause adverse pregnancy outcomes for mothers and harmful lead effects on fetuses. However, the reports about maternal BLL changes during pregnancy are conflicting to some extent. This article is to explore the variations in BLLs among pregnant women. The relationships of BLLs with methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms, which are associated with bone resorption, were also studied. A total of 973 women, including 234, 249, and 248 women in their first, second, and third trimesters, respectively, and 242 non-pregnant women, were recruited at the Wuhan Women and Children Medical Health Center. Methods BLLs were determined using a graphite furnace atomic absorption spectrometer. Single-nucleotide polymorphisms of MTHFR were identified with the TaqMan probe method. Results The geometric mean (geometric standard deviation) of BLLs was 16.2 (1.78) μg/L for all participants. All the studied MTHFR alleles were in Hardy-Weinberg equilibrium. Multiple-linear regression analysis revealed the following results. Among the pregnant women, those that carried MTHFR 677CC (i.e. wild-genotype homozygote) and 1298CC (i.e. mutant-genotype homozygote) exhibited higher BLLs than those that carried 677CT/TT (standardized β = 0.074, P = 0.042) and 1298AC/AA (standardized β = 0.077, P = 0.035) when other covariates (e.g., age, no. of children, education and income, etc.) were adjusted. The BLLs of pregnant women consistently decreased during the pregnancy and these levels positively correlated with BMI (standard β = 0.086–0.096, P<0.05). Conclusions The 1298CC mutant-type homozygote in the MTHFR gene is a risk factor for high BLLs among low-level environmental lead-exposed Chinese pregnant women, whose BLLs consistently decreased during gestation. PMID:25723397

  18. Nitrate reductase mutation alters potassium nutrition as well as nitric oxide-mediated control of guard cell ion channels in Arabidopsis.

    PubMed

    Chen, Zhong-Hua; Wang, Yizhou; Wang, Jian-Wen; Babla, Mohammad; Zhao, Chenchen; García-Mata, Carlos; Sani, Emanuela; Differ, Christopher; Mak, Michelle; Hills, Adrian; Amtmann, Anna; Blatt, Michael R

    2016-03-01

    Maintaining potassium (K(+) ) nutrition and a robust guard cell K(+) inward channel activity is considered critical for plants' adaptation to fluctuating and challenging growth environment. ABA induces stomatal closure through hydrogen peroxide and nitric oxide (NO) along with subsequent ion channel-mediated loss of K(+) and anions. However, the interactions of NO synthesis and signalling with K(+) nutrition and guard cell K(+) channel activities have not been fully explored in Arabidopsis. Physiological and molecular techniques were employed to dissect the interaction of nitrogen and potassium nutrition in regulating stomatal opening, CO2 assimilation and ion channel activity. These data, gene expression and ABA signalling transduction were compared in wild-type Columbia-0 (Col-0) and the nitrate reductase mutant nia1nia2. Growth and K(+) nutrition were impaired along with stomatal behaviour, membrane transport, and expression of genes associated with ABA signalling in the nia1nia2 mutant. ABA-inhibited K(+) in current and ABA-enhanced slow anion current were absent in nia1nia2. Exogenous NO restored regulation of these channels for complete stomatal closure in nia1nia2. While NO is an important signalling component in ABA-induced stomatal closure in Arabidopsis, our findings demonstrate a more complex interaction associating potassium nutrition and nitrogen metabolism in the nia1nia2 mutant that affects stomatal function. PMID:26508536

  19. Cerebral venous thrombosis associated with homozygous factor V Leiden mutation in a 15-year-old girl of Tunisian origin.

    PubMed

    Salem-Berrabah, Olfa Ben; Fekih-Mrissa, Nejiba; Laayouni, Samy; Gritli, Nasreddine; Mrissa, Ridha

    2011-01-01

    Cerebral venous thrombosis (CVT) is a rare disease. It has numerous and complex etiologies. Inherited or acquired prothrombotic states play a key role in the development of this disease, such as factor V G1691A mutation (FV Leiden). A 15-year-old girl presented to the Department of Neurology with a complaint of severe headache with visual blurring. The diagnosis of CVT was not initially suspected because of the patient's condition on presentation. An MRI showed thrombosis in the superior sagittal sinus, confirming venous stroke. Anticardiolipin and antiphospholipid antibodies were assessed. In addition, inherited prothrombotic defects, such as protein C, protein S, and antithrombin deficiencies, and genetic mutations for FV Leiden, prothrombin gene G20210A (FII G20210A), and methyltetrahydrofolate reductase C677T (MTHFR C677T) were studied. All results were unremarkable except for the unique homozygous FV Leiden mutation, which likely contributed to this prothrombotic situation. This study highlights the fact that FV Leiden may play a significant role in the onset of CVT in young patients. PMID:22048515

  20. Evaluation of DNA methylation at imprinted DMRs in the spermatozoa of oligozoospermic men in association with MTHFR C677T genotype.

    PubMed

    Louie, K; Minor, A; Ng, R; Poon, K; Chow, V; Ma, S

    2016-09-01

    Altered DNA methylation has been previously identified in the spermatozoa of infertile men; however, the origins of these errors are poorly understood. DNA methylation is an epigenetic modification which is thought to play a fundamental role in male germline development. DNA methylation reactions rely on the cellular availability of methyl donors, which are primarily products of folate metabolism, where a key enzyme is methylenetetrahydrofolate reductase (MTHFR). The MTHFR C677T single nucleotide polymorphism (SNP) reduces enzyme activity and may potentially alter DNA methylation processes during germline development. The objective of this study was to determine whether altered DNA methylation in spermatozoa is associated with the MTHFR C677T SNP. DNA methylation was evaluated at the H19, IG-GTL2, and MEST imprinted differentially methylated regions in the spermatozoa of 53 men - 44 oligozoospermic men and nine fertile men with normal sperm parameters via bisulfite sequencing of sperm clones. The 44 infertile men were stratified by severity of oligozoospermia - three normal (>15 million spermatozoa/mL), eight moderate (5-15 million spermatozoa/mL), 23 severe (1-5 million spermatozoa/mL), and 10 very severe (<1 million spermatozoa/mL). MTHFR C677T SNP genotyping was conducted in a subset of 44 peripheral blood samples via restriction fragment length polymorphism. A total of three men - severe oligozoospermic and CT genotype - were found to be altered, which is defined as having ≥50% of their clones altered, where an altered clone was in turn defined as ≥50% of CpGs with incorrect DNA methylation patterns. The incidence of three altered men within the CT subgroup, however, was not significantly higher than the incidence in the CC subgroup. Taken together, altered DNA methylation in spermatozoa was not significantly associated with the MTHFR C677T SNP; however, there was a trend for higher incidence of alterations among severe oligozoospermic infertile men

  1. Cardiovascular Events Are Not Associated with MTHFR Polymorphisms, But Are Associated with Methotrexate Use and Traditional Risk Factors in US Veterans with Rheumatoid Arthritis

    PubMed Central

    Davis, Lisa A.; Cannon, Grant W.; Pointer, Lauren F.; Haverhals, Leah M.; Wolff, Roger K.; Mikuls, Ted R.; Reimold, Andreas M.; Kerr, Gail S.; Richards, J. Steuart; Johnson, Dannette S.; Valuck, Robert; Prochazka, Allan; Caplan, Liron

    2014-01-01

    Objective C677T and A1298C polymorphisms in the enzyme methylenetetrahydrofolate reductase (MTHFR) have been associated with increased cardiovascular (CV) events in non-rheumatoid arthritis (RA) populations. We investigated potential associations of MTHFR polymorphisms and use of methotrexate (MTX) with time-to-CV event in data from the Veterans Affairs Rheumatoid Arthritis (VARA) registry. Methods VARA participants were genotyped for MTHFR polymorphisms. Variables included demographic information, baseline comorbidities, RA duration, autoantibody status, and disease activity. Patients’ comorbidities and outcome variables were defined using International Classification of Diseases-9 and Current Procedural Terminology codes. The combined CV event outcome included myocardial infarction (MI), percutaneous coronary intervention, coronary artery bypass graft surgery, and stroke. Cox proportional hazards regression was used to model the time-to-CV event. Results Data were available for 1047 subjects. Post-enrollment CV events occurred in 97 patients (9.26%). Although there was a trend toward reduced risk of CV events, MTHFR polymorphisms were not significantly associated with time-to-CV event. Time-to-CV event was associated with prior stroke (HR 2.01, 95% CI 1.03–3.90), prior MI (HR 1.70, 95% CI 1.06–2.71), hyperlipidemia (HR 1.57, 95% CI 1.01–2.43), and increased modified Charlson-Deyo index (HR 1.23, 95% CI 1.13–1.34). MTX use (HR 0.66, 95% CI 0.44–0.99) and increasing education (HR 0.87, 95% CI 0.80–0.95) were associated with a lower risk for CV events. Conclusion Although MTHFR polymorphisms were previously associated with CV events in non-RA populations, we found only a trend toward decreased association with CV events in RA. Traditional risk factors conferred substantial CV risk, while MTX use and increasing years of education were protective. (First Release April 1 2013; J Rheumatol 2013;40:809–17; doi:10.3899/ jrheum.121012) PMID:23547211

  2. Geographical Distribution of MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in China: Findings from 15357 Adults of Han Nationality

    PubMed Central

    Yang, Boyi; Liu, Yuyan; Li, Yongfang; Fan, Shujun; Zhi, Xueyuan; Lu, Xiangxiang; Wang, Da; Zheng, Quanmei; Wang, Yinuo; Wang, Yanxun; Sun, Guifan

    2013-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C and methionine synthase reductase (MTRR) A66G polymorphisms are important genetic determinants for homocysteine (Hcy) levels, and are associated with several disorders. These polymorphisms are heterogeneously distributed worldwide. Our objective was to explore the geographical distributions of these polymorphisms in China. Methodologies 15357 healthy adults were recruited from 10 regions. Buccal samples were collected and genomic DNA was isolated. Genotyping was performed using the fluorogenic 5′-nuclease assay. Principal Findings The prevalence of the three polymorphisms among different populations from China varied significantly and showed apparent geographical gradients. For MTHFR C677T, the frequencies of the 677T allele and the 677TT genotype were significantly higher among northern populations and ranged from the lowest values (24.0% and 6.4%, respectively) in Hainan (southern) to the highest values (63.1% and 40.8%, respectively) in Shandong (northern). For MTHFR A1298C, the 1298C allele and the 1298CC genotype frequencies were significantly higher among southern populations and increased from low values (13.1% and 1.4%, respectively) in Shandong to high values (25.7% and 6.7%, respectively) in Hainan. For A66G, the 66G allele and the 66GG genotype frequencies increased from lower values (23.7% and 5.4%, respectively) in Shandong to higher values (29.2% and 8.6%, respectively) in Hainan. The overall frequency of the 677T allele, 677TT genotype, 1298C allele, 1298CC genotype, 66G allele and 66GG genotype in the Chinese Han population was 45.2%, 23.2%, 18.6%, 3.9%, 25.7%, and 6.6%, respectively. No gender differences were found in the prevalence of both the MTHFR C677T and MTRR A66G polymorphisms. Conclusions This study indicates that there are marked geographical variations in the prevalence of the three polymorphisms among Chinese Han populations. Our baseline data may be useful for

  3. Heterotrimeric NADH-Oxidizing Methylenetetrahydrofolate Reductase from the Acetogenic Bacterium Acetobacterium woodii

    PubMed Central

    Bertsch, Johannes; Öppinger, Christian; Hess, Verena; Langer, Julian D.

    2015-01-01

    ABSTRACT The methylenetetrahydrofolate reductase (MTHFR) of acetogenic bacteria catalyzes the reduction of methylene-THF, which is highly exergonic with NADH as the reductant. Therefore, the enzyme was suggested to be involved in energy conservation by reducing ferredoxin via electron bifurcation, followed by Na+ translocation by the Rnf complex. The enzyme was purified from Acetobacterium woodii and shown to have an unprecedented subunit composition containing the three subunits RnfC2, MetF, and MetV. The stable complex contained 2 flavin mononucleotides (FMN), 23.5 ± 1.2 Fe and 24.5 ± 1.5 S, which fits well to the predicted six [4Fe4S] clusters in MetV and RnfC2. The enzyme catalyzed NADH:methylviologen and NADH:ferricyanide oxidoreductase activity but also methylene-tetrahydrofolate (THF) reduction with NADH as the reductant. The NADH:methylene-THF reductase activity was high (248 U/mg) and not stimulated by ferredoxin. Furthermore, reduction of ferredoxin, alone or in the presence of methylene-THF and NADH, was never observed. MetF or MetVF was not able to catalyze the methylene-THF-dependent oxidation of NADH, but MetVF could reduce methylene-THF using methyl viologen as the electron donor. The purified MTHFR complex did not catalyze the reverse reaction, the endergonic oxidation of methyl-THF with NAD+ as the acceptor, and this reaction could not be driven by reduced ferredoxin. However, addition of protein fractions made the oxidation of methyl-THF to methylene-THF coupled to NAD+ reduction possible. Our data demonstrate that the MTHFR of A. woodii catalyzes methylene-THF reduction according to the following reaction: NADH + methylene-THF → methyl-THF + NAD+. The differences in the subunit compositions of MTHFRs of bacteria are discussed in the light of their different functions. IMPORTANCE Energy conservation in the acetogenic bacterium Acetobacterium woodii involves ferredoxin reduction followed by a chemiosmotic mechanism involving Na

  4. Thymidylate synthase and methylenetetrahy-drofolate reductase gene polymorphisms and gastric cancer susceptibility in a population of Northern Brazil.

    PubMed

    Araújo, M D; Borges, B N; Rodrigues-Antunes, S; Burbano, R M R; Harada, M L

    2015-01-01

    The folate metabolic pathway, which is involved in DNA synthesis and methylation, is associated with individual susceptibility to several diseases, including gastric tumors. In this study, we investigated four polymorphisms [thymidylate synthase enhancer region, single nucleotide polymorphism thymidylate synthase 5' (TS5'), TS3' untranslated region, and methylenetetrahydrofolate reductase (MTHFR) 677C> T] in 2 genes related to the folate pathway, TS and MTHFR, and their possible association with the risk gastric cancer development in a population from Pará state, Brazil. For the TS enhancer region, TS3' untranslated region, and single nucleotide polymorphism TS5' polymorphisms, no significant results were obtained. For the MTHFR 677C>T polymorphism, TT genotype carriers had a higher risk of developing tumors in the antrum (P = 0.19 vs CC and P = 0.02 vs CT) and intestine (odds ratio = 4.18, 95% confidence interval = 0.66-26.41; P = 0.252 vs CC and odds ratio = 2.25, 95% confidence interval = 0.32-15.75; P = 0.725 vs CT). Those carrying at least 1 T allele had an increased risk of lymph node metastasis (odds ratio = 3.00, 95% confidence interval = 0.88-10.12; P = 0.133). Our results suggest that polymorphisms in MTHFR affect the susceptibility to gastric tumors in the Brazilian population and may be a factor causing poor prognosis in such patients. PMID:26345936

  5. Plasma homocysteine in adolescents depends on the interaction between methylenetetrahydrofolate reductase genotype, lipids and folate: a seroepidemiological study

    PubMed Central

    Gil-Prieto, Ruth; Hernández, Valentín; Cano, Beatriz; Oya, Manuel; Gil, Ángel

    2009-01-01

    Background Many publications link high homocysteine levels to cardiovascular disease. In Spain there is little information on the prevalence of hyperhomocysteinaemia and associated vitamin factors among the general population, and less still among children. Cardiovascular risk factors in the childhood population may be related to the appearance of cardiovascular disease at adult age. The aim of this study is to establish a definition of hyperhomocysteinaemia in adolescents and to analyze the influence of vitamin and metabolic factors in homocysteine levels in this population group. Methods Descriptive, cross-sectional epidemiological study to estimate serum homocysteine, vitamin B12 and folate levels, as well as plasma total, HDL- and LDL- cholesterol in a schoolgoing population aged 13 to 17 years in Madrid, Spain. Spearman correlation analysis was performed to ascertain quantitative comparison, Pearson's χ2 test (frequency < 5, Fisher) was used for comparison of prevalences, Mann-Whitney U and Kruskal-Wallis test were used for comparison of means and Bonferroni correction was used for post-hoc tests. A multivariate logistic regression model was performed in the multivariate analysis. Results Based on the classic values for definition of hyperhomocysteinaemia in adults, prevalence of hyperhomocysteinaemia in the study population was: 1.26% for 15 μmol/L; and 2.52% for 12 μmol/L. Deficits in HDL cholesterol and serum folate levels yielded adjusted Odds Ratios (OR) for hyperhomocysteinemia of 2.786, 95% CI (1.089-7.126), and 5.140, 95% CI (2.347-11.256) respectively. Mutation of the methylenetetrahydrofolate reductase (MTHFR) C677T genotype also raises the risk of hyperhomocysteinaemia (CC→CT: OR = 2.362; 95% CI (1.107-5.042) CC→TT: OR = 6.124, 95% CI (2.301-16.303)) Conclusion A good definition of hyperhomocysteinaemia in adolescents is the 90th percentile, equivalent to 8.23 μmol/L. Risk factors for hyperhomocysteinaemia are cHDL and folate deficiency, and

  6. Screening for C677T and A1298C MTHFR polymorphisms in patients with epilepsy and risk of hyperhomocysteinemia.

    PubMed

    Caccamo, D; Condello, S; Gorgone, G; Crisafulli, G; Belcastro, V; Gennaro, S; Striano, P; Pisani, F; Ientile, R

    2004-01-01

    Hyperhomocysteinemia can result from decreased methylenetetrahydrofolate reductase (MTHFR) enzyme activity, owing to genetic polymorphisms andor inadequate folate intake. This study was aimed at investigating the prevalence of C677T and A1298C MTHFR polymorphisms, and their impact on hyperhomocysteinemia in 95 epileptic patients and 98 controls. Double gradient-denaturing gradient gel electrophoresis screening revealed that the frequency of T677 polymorphic allele was similar between cases and controls (46.3% vs 42.3%), whereas that of C1298 allele was significantly higher in patients (30.5% vs 19.4%, p < 0.05). Significant differences between the two groups were also found for the frequencies of genotypes AA1298 (46.3% in cases vs 67.3% in controls, p < 0.01) and AC1298 (46.3% in cases vs 26.6% in controls, p < 0.01). Other genotype frequencies did not show any statistically significant differences. Haplotype frequencies significantly differed between the two groups. The CT677/AC1298 diplotype was significantly more frequent in epileptic patients than in controls (32.6% vs 18.4%, p < 0.05). Patients treated with enzyme-inducing antiepileptic drugs, having this diplotype and concomitant low folate concentration (i.e., < 3.4 nmol/L), exhibited plasma homocysteine levels significantly higher than normal values (27.1 +/- 2.44 micromol/L, p < 0.001). This increase, however, was lower than that observed in folate-deficient patients with diplotype TT677/AA1298 (41.3 +/- 3.41 micromol/L, p < 0.001). Indeed, these two diplotypes could be regarded as risk factors for hyperhomocysteinemia. Conversely, we found that the CC677/AA1298 diplotype was significantly more frequent in controls (p < 0.01), suggesting a protective role. Our study suggests that both C677T and A1298C MTHFR polymorphisms should be examined when assessing genetic risk factors of hyperhomocysteinemia in epilepsy. PMID:15970629

  7. 5,10-methylenetetrahydrofolate reductase 677 and 1298 polymorphisms, folate intake, and microsatellite instability in colon cancer.

    PubMed

    Eaton, Allison M; Sandler, Robert; Carethers, John M; Millikan, Robert C; Galanko, Joseph; Keku, Temitope O

    2005-08-01

    The 5,10-methylenetetrahydrofolate reductase (MTHFR) gene plays a critical role in folate metabolism. Studies on the association between MTHFR polymorphisms and length changes in short tandem repeat DNA sequences [microsatellite instability (MSI)] are inconsistent. Using data from colon cancer cases (n=503) enrolled as part of an existing population-based case-control study, we investigated the association between MTHFR 677 and MTHFR 1298 polymorphisms and MSI. We also examined whether the association was modified by folate intake. Participants were case subjects enrolled as part of the North Carolina Colon Cancer Study. Consenting cases provided information about lifestyle and diet during in-home interviews as well as blood specimens and permission to obtain tumor blocks. DNA from normal and tumor tissue sections was used to determine microsatellite status (MSI). Tumors were classified as MSI if two or more microsatellite markers (BAT25, BAT26, D5S346, D2S123, and D17S250) had changes in the number of DNA sequence repeats compared with matched nontumor tissue. Tumors with one positive marker (MSI-low) or no positive markers (microsatellite stable) were grouped together as non-MSI tumors (microsatellite stable). MTHFR 677 and MTHFR 1298 genotypes were determined by real-time PCR using the 5' exonuclease (Taqman) assay. Logistic regression was used to calculate odds ratio (OR) and 95% confidence intervals (95% CI). MSI was more common in proximal tumors (OR, 3.8; 95% CI, 1.7-8.4) and in current smokers (OR, 4.0; 95% CI, 1.6-9.7). Compared with MTHFR 677 CC referent, MTHFR 677 CT/TT genotype was inversely associated with MSI among White cases (OR, 0.36; 95% CI, 0.16-0.81) but not significant among African Americans. Although not statistically significant, a similar inverse association was observed between MTHFR 677 CT/TT genotype and MSI among the entire case subjects (OR, 0.54; 95% CI, 0.26-1.10). Among those with adequate folate intake (>400 microg total folate

  8. Effect of polymorphisms of the MTHFR and APOE genes on susceptibility to diabetes and severity of diabetic retinopathy in Brazilian patients.

    PubMed

    Errera, F I V; Silva, M E R; Yeh, E; Maranduba, C M C; Folco, B; Takahashi, W; Pereira, A C; Krieger, J E; Passos-Bueno, M R

    2006-07-01

    Diabetes mellitus (DM) is a highly prevalent complex genetic disorder. There has been a worldwide effort in the identification of susceptibility genes for DM and its complications, and the 5-10-methylenetetrahydrofolate reductase (MTHFR) and apolipoprotein-E (APOE) genes have been considered good candidate susceptibility genes to this condition. The objectives of the present study were to determine if the 677T MTHFR and epsilon2/epsilon3/epsilon4 APOE alleles are risk factors for DM and for severity of diabetic retinopathy (DR). A total of 248 individuals were studied: 107 healthy individuals and 141 diabetic patients (46 with type 1 diabetes and 95 with type 2 diabetes), who also had DR (81 with non-proliferative DR and 60 with proliferative DR). The polymorphisms were analyzed by PCR followed by digestion with restriction enzyme or the single-nucleotide primer extension method. No evidence of association between the 677TT genotype of MTHFR gene and DM [cases: TT = 10/95 (10.6%); controls: TT = 14/107 (13%)] or with severity of DR was observed [cases: TT = 5/60 (8.5%); controls: TT = 9/81 (11.1%); P > 0.05]. We also did not find evidence of an association between APOE alleles and proliferative DR (epsilon2, epsilon3 and epsilon4 in cases: 9, 76, and 15%, and in controls: 5, 88, and 12%, respectively) but the carriers of epsilon2 allele were more frequent among patients with type 2 DM and DR than in controls [cases: 15/95 (15.8%); controls: 7/107 (6.5%); P < 0.05]. Therefore, our results suggest that the epsilon2 allele/APOE might be a risk factor for diabetes in the Brazilian population. PMID:16862278

  9. Association between C677T and A1298C polymorphisms of the MTHFR gene and risk of male infertility: a meta-analysis.

    PubMed

    Yang, Y; Luo, Y Y; Wu, S; Tang, Y D; Rao, X D; Xiong, L; Tan, M; Deng, M Z; Liu, H

    2016-01-01

    Published studies on the association between the C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene and male infertility risk are controversial. To obtain a more precise evaluation, we performed a meta-analysis based on published case-control studies. We conducted an electronic search of PubMed, EMBASE, the Cochrane Library, the Web of Science, and the China Knowledge Resource Integrated Database for papers on MTHFR gene C677T and A1298C polymorphisms and male infertility risk. Pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were used to assess the strength of association in homozygote, heterozygote, dominant, recessive, and additive models. Statistical heterogeneity, test of publication bias, and sensitivity analysis were carried out using the STATA software (Version 13.0). Overall, 21 studies of C677T (4505 cases and 4024 controls) and 13 studies of A1298C (2785 cases and 3094 controls) were included in this meta-analysis. For C677T, the homozygote comparison results were OR = 1.629, 95%CI (1.215- 2.184), and the recessive model results were OR = 1.462 (1.155- 1.850). For A1298C, the homozygote comparison results were OR = 1.289 (1.029-1.616), and the recessive model results were OR = 1.288 (1.034-1.604). In conclusion, the current meta-analysis showed that the MTHFR C677T polymorphism was associated with a significantly increased male infertility risk in the Asian and overall populations, but not in the Caucasian population, and there was a significant association between the A1298C polymorphism and male infertility risk in the Asian, Caucasian, and overall groups. PMID:27173242

  10. A novel lateral flow assay based on GoldMag nanoparticles and its clinical applications for genotyping of MTHFR C677T polymorphisms.

    PubMed

    Hui, Wenli; Zhang, Sinong; Zhang, Chao; Wan, Yinsheng; Zhu, Juanli; Zhao, Gang; Wu, Songdi; Xi, Dujuan; Zhang, Qinlu; Li, Ningning; Cui, Yali

    2016-02-14

    Current techniques for single nucleotide polymorphism (SNP) detection require tedious experimental procedures and expensive and sophisticated instruments. In this study, a visual genotyping method has been successfully established via combining ARMS-PCR with gold magnetic nanoparticle (GoldMag)-based lateral flow assay (LFA) and applied to the genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T. C677T substitution of the gene MTHFR leads to an increased risk of diseases. The genotyping result is easily achievable by visual observation within 5 minutes after loading of the PCR products onto the LFA device. The system is able to accurately assess a broad detection range of initial starting genomic DNA amounts from 5 ng to 1200 ng per test sample. The limit of detection reaches 5 ng. Furthermore, our PCR-LFA system was applied to clinical trials for screening 1721 individuals for the C677T genotypes. The concordance rate of the genotyping results detected by PCR-LFA was up to 99.6% when compared with the sequencing results. Collectively, our PCR-LFA has been proven to be rapid, accurate, sensitive, and inexpensive. This new method is highly applicable for C677T SNP screening in laboratories and clinical practices. More promisingly, it could also be extended to the detection of SNPs of other genes. PMID:26804455

  11. A novel lateral flow assay based on GoldMag nanoparticles and its clinical applications for genotyping of MTHFR C677T polymorphisms

    NASA Astrophysics Data System (ADS)

    Hui, Wenli; Zhang, Sinong; Zhang, Chao; Wan, Yinsheng; Zhu, Juanli; Zhao, Gang; Wu, Songdi; Xi, Dujuan; Zhang, Qinlu; Li, Ningning; Cui, Yali

    2016-02-01

    Current techniques for single nucleotide polymorphism (SNP) detection require tedious experimental procedures and expensive and sophisticated instruments. In this study, a visual genotyping method has been successfully established via combining ARMS-PCR with gold magnetic nanoparticle (GoldMag)-based lateral flow assay (LFA) and applied to the genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T. C677T substitution of the gene MTHFR leads to an increased risk of diseases. The genotyping result is easily achievable by visual observation within 5 minutes after loading of the PCR products onto the LFA device. The system is able to accurately assess a broad detection range of initial starting genomic DNA amounts from 5 ng to 1200 ng per test sample. The limit of detection reaches 5 ng. Furthermore, our PCR-LFA system was applied to clinical trials for screening 1721 individuals for the C677T genotypes. The concordance rate of the genotyping results detected by PCR-LFA was up to 99.6% when compared with the sequencing results. Collectively, our PCR-LFA has been proven to be rapid, accurate, sensitive, and inexpensive. This new method is highly applicable for C677T SNP screening in laboratories and clinical practices. More promisingly, it could also be extended to the detection of SNPs of other genes.

  12. Atherosclerosis in male patients with ankylosing spondylitis: the relation with methylenetetrahydrofolate reductase (C677T) gene polymorphism and plasma homocysteine levels.

    PubMed

    Geçene, Muharrem; Tuncay, Figen; Borman, Pınar; Yücel, Dogan; Senes, Mehmet; Yılmaz, Behice Kaniye

    2013-06-01

    The aim of this study was to determine the intima-media thickness (IMT) in carotid arteries and to assess the relation of these values with plasma homocysteine (pHcy) levels and methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism in patients with Ankylosing spondylitis (AS). Serum lipids, vitamin B12, folic acid, pHcy and acute phase protein levels were measured in all cases. MTHFR C677T gene polymorphisms were determined, and IMT of main carotid artery were evaluated ultrasonographically in all subjects. Bath Ankylosing Spondylitis Disease Activity Index, Ankylosing Spondylitis Disease Activity score and Bath Ankylosing Spondylitis Metrology Index were used to assess disease activity and spinal mobility. Fifty AS patients (mean age of 36.6 ± 4.79 years) and 50 control subjects (36.34 ± 4.72 years) were included in the study. Plasma homocysteine levels of AS patients and control group were also similar (14.26 ± 9.96 vs. 11.81 ± 5.53 μmol/L). Hyperhomocysteinemia was present in 11 subjects in patient group (22.0 %), while it was seen in 5 subjects in the control group (10.0 %). The MTHFR C677T genotype distribution was as follows: CC 31 (62 %), CT 14 (28 %), TT 5 (10 %) in AS patients. The mean carotid IMT values were also found to be similar between the groups. The most important factor influencing pHcy level was found as MTHFR 677TT genotype. We indicated no difference of atherosclerosis indices revealed by IMT values and pHcy levels AS patients and control subjects. But an association between MTHFR 677 gene polymorphism and pHcy levels was concluded, which may suggest that MTHFR 677 TT polymorphism may be a potential prognostic factor for cardiovascular disease in patients with AS. PMID:23247802

  13. Association of methylenetetrahydrofolate reductase C677T-A1298C polymorphisms with risk for esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis.

    PubMed

    Ekiz, F; Ormeci, N; Coban, S; Karabulut, H G; Aktas, B; Tukun, A; Tuncali, T; Yüksel, O; Alkış, N

    2012-07-01

    Incidence of the esophagus adenocarcinoma has been dramatically increasing in Western countries since the last decade. Gastroesophageal reflux disease and Barrett's esophagus are risk factors for adenocarcinoma. Methylenetetrahydrofolate reductase (MTHFR) genes play a key role not only in folate metabolism but also in esophagus, stomach, pancreatic carcinoma, and acute leukemias. Studies have suggested that genetic polymorphisms of MTHFR (C677T) may clarify the causes and events involved in esophageal carcinogenesis. In this study, we evaluated MTHFR C677T and A1298C polymorphisms, and vitamin B12, folate, and plasma homocystein levels in patients with esophageal adenocarcinoma (EAC), Barrett's esophagus (BE), chronic esophagitis, and healthy controls (n = 26, n = 14, n = 30, and n = 30, respectively). The mean age of patients in the EAC and BE groups was significantly higher compared with the control group (P < 0.001, P = 0.003, respectively). In all patient groups, serum folate levels were significantly lower than that of the control group (P < 0.01, P < 0.05, and P < 0.01, respectively). There was no statistically significant association between folate levels and MTHFR gene polymorphisms. No differences were found in terms of MTHFR gene polymorphisms, homocystein, and B12 levels among the groups. MTHFR gene polymorphisms and folate deficiency are not predictors of early esophageal carcinoma. However, further studies using larger series of patients are needed to evaluate the effect of genetic polymorphisms in the folate metabolic pathway and to clarify the role of folate deficiency and folate metabolism in the development of esophagus adenocarcinoma. PMID:21951971

  14. Meta-analyses of the methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and risk of head and neck and lung cancer.

    PubMed

    Boccia, Stefania; Boffetta, Paolo; Brennan, Paul; Ricciardi, Gualtiero; Gianfagna, Francesco; Matsuo, Keitaro; van Duijn, Cornelia M; Hung, Rayjean J

    2009-01-01

    Authors report the results of four meta-analyses of studies that examined the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and head and neck cancer (nine studies, 2076 cases and 4834 controls for C677T; four studies, 1439 cases and 3941 controls for A1298C), and lung cancer (ten studies, 5274 cases and 7435 controls for C677T; seven studies, 5098 cases and 6243 controls for A1298C). The summary odds ratio (OR) of head and neck cancer was 0.92 (95% CI: 0.76-1.11) for MTHFR 677 TT and 0.68 (95% CI: 0.37-1.26) for MTHFR 1298 CC. The OR of lung cancer was 1.22 [95% confidence interval (CI): 0.95-1.55] for MTHFR 677 TT and 1.07 (95% CI: 0.83-1.38) for MTHFR 1298 CC. Results from the meta-analysis of three studies on C677T stratified according to dietary folate intake showed an increased risk for individuals with low folate intake (OR = 1.37, 95% CI: 0.92-2.06 for head and neck and OR = 1.28, 95% CI: 0.97-1.68 for lung) versus high folate intake (OR = 0.85, 95% CI: 0.63-1.16 for head and neck, and OR = 0.94, 95% CI: 0.79-1.12 for lung). Despite the lack of formal statistical significance, these findings are consistent with the hypothesis that folate play a role in lung and head/neck carcinogenesis, and show the need to incorporate data on folate intake when interpreting results of MTHFR polymorphisms in relation to cancer risk. PMID:18789576

  15. Methylenetetrahydrofolate Reductase A1298C Polymorphism and Breast Cancer Risk: A Meta-analysis of 33 Studies

    PubMed Central

    Rai, V

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) enzyme is essential for DNA synthesis and DNA methylation, and its gene polymorphisms have been implicated as risk factors for birth defects, neurological disorders, and different types of cancers. Several studies have investigated the association between the MTHFR A1298C polymorphism and breast cancer (BC) risk, but the results were inconclusive. To assess the risk associated with MTHFR A1298C polymorphism, a comprehensive meta-analysis was performed. PubMed, Google Scholar, Elsevier and Springer Link databases were searched for case-control studies relating the association between MTHFR A1298C polymorphism and BC risk and estimated summary odds ratios (ORs) with confidence intervals (CIs) for assessment. Up to January 2014, 33 case-control studies involving 15,919 BC patients and 19,700 controls were included in the present meta-analysis. The results showed that the A1298C polymorphism was not associated with BC risk in all the five genetic models (C vs. A allele (allele contrast): OR = 0.99, 95% confidence interval (CI): 0.93–1.05; AC versus AA (heterozygote/codominant): OR = 0.97, 95% CI: 0.89–1.04; CC versus AA (homozygote): OR = 0.99, 95% CI: 0.91–1.06; CC + AC versus AA (dominant model): OR = 0.97, 95% CI: 0.90–1.05; and CC versus AC + AA (recessive model): OR = 0.99, 95% CI: 0.91–1.07). The present meta-analysis did not support any association between the MTHFR A1298C polymorphism and BC risk. PMID:25506474

  16. Normal Weight Obese syndrome: role of single nucleotide polymorphism of IL-1 5Ralpha and MTHFR 677C-->T genes in the relationship between body composition and resting metabolic rate.

    PubMed

    Di Renzo, L; Bigioni, M; Bottini, F G; Del Gobbo, V; Premrov, M G; Cianci, R; De Lorenzo, A

    2006-01-01

    We have identified a subset of metabolically obese, but normal weight individuals, with potentially increased risks of developing the metabolic syndrome, despite their normal body mass index. We determined the relationship among body fat distribution, resting metabolic rate (RMR), total body water amount (%TBW), selected gene polymorphism on interleukin-15 receptor-alpha (IL-15Ralpha) and methylenetetrahydrofolate reductase 677C-->T (MTHFR 677C-->T), to distinguish normal weight obese (NWO) from nonobese with a normal metabolic profile and obese individuals. We analysed anthropometric variables, body composition by Dual energy X-ray Absorptiometry (DXA), RMR by indirect calorimetry, %TBW by bioimpedence analysis (BIA), MTHFR 677C-->T and IL-15Ralpha genotypes of 128 clinically healthy Caucasian individuals. We compared a group of female, defined as NWO and characterised by a BMI < or = 25 kg/m(2) and FM > or = 30% with groups of others female, and males, represented by nonobese with a BMI < or = 25 kg/m(2) and FM < or = 30%, and preobese-obese individuals with BMI > or = 25 kg/m(2) and %FM > or = 30%; none of the males was classified as NWO. Significant correlations were found among body fat mass distribution, metabolic variables, percentage of total body water distribution and selected genetic variations. The variables that contributed significantly to the separation of classes were body tissue (Tissue), %TBW, RMR, the volumes of both oxygen (VO2) and carbon dioxide (VCO2). The distribution of MTHFR 677C-->T and IL-15 genotypes was significantly different between classes. Our data highlight that NWO individuals showed a significant relationship between the decrease in the basal metabolism (RMR), body fat mass increasing and total water amount. Possession of wild type homozygotes genotypes regarding IL-15Ralpha cytokine and 677C-->T MTHFR enzyme characterised NWO individuals. PMID:17121316

  17. Association of 677 C>T (rs1801133) and 1298 A>C (rs1801131) Polymorphisms in the MTHFR Gene and Breast Cancer Susceptibility: A Meta-Analysis Based on 57 Individual Studies

    PubMed Central

    Li, Kai; Li, Wusheng; Dong, Xi

    2014-01-01

    Objective The 677 C>T and 1298 A>C polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene have been widely reported and considered to have a significant effect on breast cancer risk, but the results are inconsistent. A meta-analysis based on 57 eligible studies was carried out to clarify the role of MTHFR gene polymorphisms in breast cancer. Methods and Results Eligible articles were identified by searching databases including PubMed, Web of Science, EMBASE, CNKI and CBM for the period up to August 2012. Finally, a total of 57 studies were included in this meta-analysis. Crude ORs with 95% CIs were used to assess the association between the MTHFR polymorphisms and breast cancer risk. The pooled ORs were performed with additive model, dominant model and recessive model, respectively. Subgroup analysis was also performed by ethnicity. The statistical heterogeneity across studies was examined with χ2-based Q-test. A meta-analysis was performed using the Stata 12.0 software. Overall, the 677 C allele was significantly associated with breast cancer risk (OR = 0.942, 95%CI = 0.898 to 0.988) when compared with the 677 T allele in the additive model, and the same results were also revealed under other genetic models. Simultaneously, the 1298 A allele was not associated with the breast cancer susceptibility when compared with the 1298 C allele (OR = 0.993, 95%CI = 0.978 to 1.009). Furthermore, analyses under the dominant, recessive and the allele contrast model yielded similar results. Conclusions The results of this meta-analysis suggest that 677 C>T polymorphism in the MTHFR gene may contribute to breast cancer development. However, the 1298 A>C polymorphism is not significantly associated with increased risks of breast cancer. PMID:24945727

  18. Polymorphisms in the MTHFR gene influence embryo viability and the incidence of aneuploidy.

    PubMed

    Enciso, María; Sarasa, Jonás; Xanthopoulou, Leoni; Bristow, Sara; Bowles, Megan; Fragouli, Elpida; Delhanty, Joy; Wells, Dagan

    2016-05-01

    MTHFR is an important enzyme in the metabolism of folic acid and is crucial for reproductive function. Variation in the sequence of MTHFR has been implicated in subfertility, but definitive data are lacking. In the present study, a detailed analysis of two common MTHFR polymorphisms (c.677C>T and c.1298A>C) was performed. Additionally, for the first time, the frequencies of different MTHFR alleles were assessed in preimplantation embryos. Several striking discoveries were made. Firstly, results demonstrated that maternal MTHFR c.1298A>C genotype strongly influences the likelihood of a pregnancy occurring, with the 1298C allele being significantly overrepresented amongst women who have undergone several unsuccessful assisted reproductive treatments. Secondly, parental MTHFR genotypes were shown to affect the production of aneuploid embryos, indicating that MTHFR is one of the few known human genes with the capacity to modulate rates of chromosome abnormality. Thirdly, an unusual deviation from Hardy-Weinberg equilibrium was noted for the c.677C>T polymorphism in subfertile patients, especially those who had experienced recurrent failure of embryo implantation or miscarriage, potentially explained by a rare case of heterozygote disadvantage. Finally, a dramatic impact of the MTHFR 677T allele on the capacity of chromosomally normal embryos to implant is described. Not only do these findings raise a series of interesting biological questions, but they also argue that testing of MTHFR could be of great clinical value, identifying patients at high risk of implantation failure and revealing the most viable embryos during in vitro fertilisation (IVF) cycles. PMID:27068821

  19. MTHFR (C677T) CT genotype and CT-apoE3/3 genotypic combination predisposes the risk of ischemic stroke.

    PubMed

    Vijayan, Murali; Chinniah, Rathika; Ravi, Padma Malini; Sivanadham, Ramgopal; Mosses Joseph, Arun Kumar; Vellaiappan, Neethi Arasu; Krishnan, Jeyaram Illiayaraja; Karuppiah, Balakrishnan

    2016-10-15

    The predisposition to ischemic stroke (IS) might involve interactions of several genes and environmental factors. The present study was aimed to evaluate the influence of polymorphisms in methylenetetrahydrofolate reductase (MTHFR-C677T) and apolipoprotein-E (apo-E) as risk factors for IS patients in south Indian population. 200 IS patients and 193 age and sex matched controls were genotyped for MTHFR-C677T and apoE by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. Statistically significant association was observed for MTHFR CT genotype (IS-Pooled: OR=4.29; p=5.01×10(-5); IS-Males: OR=4.13; p=0.001; IS-Females: OR=8.62; p=0.027; IS-Large Vessel Disease (LVD)- Pooled: OR=4.14; p=0.0002) and T allele (IS-Pooled: OR=4.82; p=1.49×10(-5); IS-Males: OR=4.33; p=0.0002; IS-Females: OR=7.99; p=0.031; IS-LVD-Pooled: OR=4.13; p=0.0001). Further, reduced frequencies of CC genotype (IS-Pooled: OR=0.20; p=9.80×10(-6); IS-Males: OR=0.25; p=0.001; IS-Females: OR=0.12; p=0.027; IS-LVD-Pooled: OR=0.23; p=0.0001) and C allele (IS-Pooled: OR=0.21; p=1.49×10(-5); IS-Males: OR=0.23; p=0.0002; IS-Females: OR=0.13; p=0.031; IS-LVD-Pooled: OR=0.24; p=0.0001) were observed in IS patients than the controls. No association was observed for apoE genotypes/alleles in IS/LVD cases. Our study demonstrated the presence of risk for MTHFR CT genotype/T allele and 'CT-3/3' (n=33 vs. 5; OR=7.42; p=0.001) genotypic combination in the development of IS in south India. Further, follow-up study of these stroke cases i.e., in later stages of the disease whether they are developing the neurological disorders such as Alzheimer's Disease (AD) and vascular dementia (VaD) is needed to draw a fruitful conclusion in connection between neurological disorders and with these two polymorphisms, before translating it into clinical practice. PMID:27378745

  20. Association between Maternal MTHFR Polymorphisms and Nonsyndromic Cleft Lip with or without Cleft Palate in Offspring, A Meta-Analysis Based on 15 Case-Control Studies

    PubMed Central

    Pan, Xinjuan; Wang, Ping; Yin, Xinjuan; Liu, Xiaozhuan; Li, Di; Li, Xing; Wang, Yongchao; Li, Hongle; Yu, Zengli

    2015-01-01

    Background The methylenetetrahydrofolate reductase (MTHFR) is thought to be involved in the development of nonsyndromic cleft lip with or without cleft palate (NSCL/P). However, conflicting results have been obtained when evaluating the association between maternal MTHFR C677T and A1298C polymorphisms and the risk of NSCL/P. In light of this gap, a meta-analysis of all eligible case-control studies was conducted in the present study. Materials and Methods A total of 15 case-control studies were ultimately identified after a comprehensive literature search and Hardy-Weinberg equilibrium (HWE) examination. Cochrane’s Q test and index of heterogeneity (I2) indicated no obvious heterogeneity among studies. Results Fixed or random-effects models were used to calculate the pooled odds ratios (ORs). The results showed that the TT genotype in mothers increased the likelihood of having NSCL/P offspring 1.25 times (95% CI: 1.047-1.494) more than the CC homozygotes. Meanwhile, maternal TT genotype increased the risk of producing NSCL/P offspring in recessive model (OR=1.325, 95% CI: 1.124-1.562). However, the CT heterozygote and the CT+TT dominant models had no association with NSCL/P offspring compared with the CC wild-type homozygote model. Subgroup analyses based on ethnicity indicated that maternal TT genotype increased the likelihood of having NSCL/P offspring in Whites (OR=1.308, 95% CI: 1.059-1.617) and Asians (OR=1.726, 95% CI: 1.090-2.733) in recessive model. Also, subgroup analyses based on source of control showed that mothers with the 677TT genotype had a significantly increased susceptibility of having NSCL/P children in hospital based population (HB) when compared with CC homozygotes (OR=1.248, 95% CI: 1.024-1.520) and un- der the recessive model (OR=1.324, 95% CI: 1.104-1.588). Furthermore, maternal A1298C polymorphism had no significant association with producing NSCL/P offspring (dominant model OR=0.952, 95% CI: 0.816-1.111, recessive model OR=0.766, 95% CI

  1. Methylenetetrahydrofolate reductase C677T polymorphism is associated with increased risk of coronary artery disease in young South African Indians.

    PubMed

    Ramkaran, Prithiksha; Phulukdaree, Alisa; Khan, Sajidah; Moodley, Devapregasan; Chuturgoon, Anil A

    2015-10-15

    Methylenetetrahydrofolate reductase (MTHFR) reduces 5',10'-methylenetetrahydrofolate to 5'-methyltetrahydrofolate, and is involved in remethylation of homocysteine to methionine, two important reactions involved in folate metabolism and methylation pathways. The common MTHFR C677T single nucleotide polymorphism (SNP) (rs1801133) has been associated with raised levels of homocysteine, a well known risk factor for coronary artery disease (CAD). CAD is a major cause of mortality worldwide. The age of onset of this chronic disorder is on the decline, particularly in the Indian population. Indians in South Africa (SA) have a higher prevalence of premature CAD compared to Black South Africans. The MTHFR C677T SNP has not been investigated in the SA Indian population. The present study therefore investigated the MTHFR C677T SNP in young SA Indian males with CAD compared to young Indian and Black male controls. A total of 290 subjects were recruited into this study which included 106 CAD patients (diagnosed on angiography, mean age 37.5, range 24-45 years), 100 Indian male controls (mean age 37.5, range 28-45 years), and 84 Black male controls (mean age 36.4, range 25-45). Polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) was used to genotype CAD patients and healthy controls. Data for clinical markers were obtained from pathology reports. There was a significant association between the 677 MTHFR variant (T) allele and CAD patients compared to the healthy Indian controls (p=0.0353, OR=2.105 95% CI 1.077-4.114). Indian controls presented with a higher frequency of the variant allele compared to Black controls (7% vs. 2% respectively, p=0.0515 OR=3.086 95% CI 0.9958-9.564). The MTHFR C677T SNP did not influence levels of total cholesterol, LDL, HDL, triglycerides, fasting glucose, fasting insulin, HbA1c or hsCRP. The higher frequency of the MTHFR 677 variant allele in South African Indians may be a contributing factor to the higher

  2. Breast cancer risk associated with gene expression and genotype polymorphisms of the folate-metabolizing MTHFR gene: a case-control study in a high altitude Ecuadorian mestizo population.

    PubMed

    López-Cortés, Andrés; Echeverría, Carolina; Oña-Cisneros, Fabián; Sánchez, María Eugenia; Herrera, Camilo; Cabrera-Andrade, Alejandro; Rosales, Felipe; Ortiz, Malena; Paz-Y-Miño, César

    2015-08-01

    Breast cancer (BC) is the leading cause of cancer-related death among women in 2014. Methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), and MTR reductase (MTRR) are enzymes that play an important role in folate metabolism. The single nucleotide polymorphisms, MTHFR C677T, A1298C, MTR A2756G, and MTRR A66G, alter plasmatic folate and homocysteine concentrations, causing problems during the repairment, synthesis, and methylation of the genetic material. Therefore, it is essential to know how BC risk is associated with histopathological and immunohistochemical characteristics, genotype polymorphisms, and gene expression in a high altitude Ecuadorian mestizo population. DNA was extracted from 195 healthy and 114 affected women. Genotypes were determined by restriction enzymes and genomic sequencing. mRNA was extracted from 26 glandular breast tissue samples, both from cancerous tissue and healthy tissue adjacent to the tumor. Relative gene expression was determined with the comparative Livak method (2(-ΔΔCT)). We found significant association between the rs1801133 (A222V) genotypes and an increased risk of BC development: C/T (odds ratio [OR] = 1.8; 95 % confidence interval [CI] = 1.1-3.2; P = 0.039), T/T (OR = 2.9; 95 % CI = 1.2-7.2; P = 0.025), and C/T + T/T (OR = 1.9; 95 % CI = 1.1-3.3; P = 0.019). Regarding relative gene expression, we found significant mRNA subexpression between the combined genotypes C/T + T/T (rs1801133) and triple negative breast cancer (TNBC) (P = 0.034). In brief, the MTHFR gene and its protein could act as potential predictive biomarkers of BC, especially TNBC among the high altitude Ecuadorian mestizo population. PMID:25801246

  3. Are MTHFR C677T and MTRR A66G Polymorphisms Associated with Overweight/Obesity Risk? From a Case-Control to a Meta-Analysis of 30,327 Subjects.

    PubMed

    Fan, Shu-Jun; Yang, Bo-Yi; Zhi, Xue-Yuan; He, Miao; Wang, Da; Wang, Yan-Xun; Wang, Yi-Nuo; Wei, Jian; Zheng, Quan-Mei; Sun, Gui-Fan

    2015-01-01

    Several studies have examined the associations of methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms with being overweight/obesity. However, the results are still controversial. We therefore conducted a case-control study (517 cases and 741 controls) in a Chinese Han population and then performed a meta-analysis by combining previous studies (5431 cases and 24,896 controls). In our case-control study, the MTHFR C677T polymorphism was not significantly associated with being overweight/obesity when examining homozygous codominant, heterozygous codominant, dominant, recessive and allelic genetic models. The following meta-analysis confirmed our case-control results. Heterogeneity was minimal in the overall analysis, and sensitivity analyses and publication bias tests indicated that the meta-analytic results were reliable. Similarly, both the case-control study and meta-analysis found no significant association between the MTRR A66G polymorphism and being overweight/obesity. However, sensitivity analyses showed that the associations between the MTRR A66G polymorphism and being overweight/obesity became significant in the dominant, heterozygous codominant and allelic models after excluding our case-control study. The results from our case-control study and meta-analysis suggest that both of the two polymorphisms are not associated with being overweight/obesity. Further large-scale population-based studies, especially for the MTRR A66G polymorphism, are still needed to confirm or refute our findings. PMID:26016497

  4. Are MTHFR C677T and MTRR A66G Polymorphisms Associated with Overweight/Obesity Risk? From a Case-Control to a Meta-Analysis of 30,327 Subjects

    PubMed Central

    Fan, Shu-Jun; Yang, Bo-Yi; Zhi, Xue-Yuan; He, Miao; Wang, Da; Wang, Yan-Xun; Wang, Yi-Nuo; Wei, Jian; Zheng, Quan-Mei; Sun, Gui-Fan

    2015-01-01

    Several studies have examined the associations of methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms with being overweight/obesity. However, the results are still controversial. We therefore conducted a case-control study (517 cases and 741 controls) in a Chinese Han population and then performed a meta-analysis by combining previous studies (5431 cases and 24,896 controls). In our case-control study, the MTHFR C677T polymorphism was not significantly associated with being overweight/obesity when examining homozygous codominant, heterozygous codominant, dominant, recessive and allelic genetic models. The following meta-analysis confirmed our case-control results. Heterogeneity was minimal in the overall analysis, and sensitivity analyses and publication bias tests indicated that the meta-analytic results were reliable. Similarly, both the case-control study and meta-analysis found no significant association between the MTRR A66G polymorphism and being overweight/obesity. However, sensitivity analyses showed that the associations between the MTRR A66G polymorphism and being overweight/obesity became significant in the dominant, heterozygous codominant and allelic models after excluding our case-control study. The results from our case-control study and meta-analysis suggest that both of the two polymorphisms are not associated with being overweight/obesity. Further large-scale population-based studies, especially for the MTRR A66G polymorphism, are still needed to confirm or refute our findings. PMID:26016497

  5. Association between methionine synthase reductase A66G polymorphism and primary infertility in Chinese males.

    PubMed

    Li, X Y; Ye, J Z; Ding, X P; Zhang, X H; Ma, T J; Zhong, R; Ren, H Y

    2015-01-01

    We examined the association between the methionine synthase reductase (MTRR A66G), methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), and methionine synthase (MS A2756G) genotypes and non-obstructive male infertility in a Chinese population. This case-control study included 162 infertile Chinese patients with azoospermia (N = 100) or oligoasthenozoospermia (N = 62) and 120 fertile men as controls. The polymorphisms MTRR A66G, MTHFR C677T, A1298C, and MS A2756G were identified by direct DNA sequencing and the results were statistically analyzed. We found no association between the incidence of any of these variants in azoospermia patients and control populations. The frequency of the MTRR66 polymorphic genotypes (AG, AG+GG) was significantly higher in the oligoasthenozoospermia group compared to the controls (P = 0.013, 0.012). Our findings revealed an association between the single-nucleotide polymorphism A66G in the MTRR gene and male infertility, particularly in oligoasthenozoospermia males, suggesting that this polymorphism is a genetic risk factor for male infertility in Chinese men. PMID:25966116

  6. Correlation between the 677C>T polymorphism in the methylene tetrahydrofolate reductase gene and serum homocysteine levels in coronary heart disease.

    PubMed

    Chen, Y Y; Wang, B N; Yu, X P

    2016-01-01

    The aim of the current study was to explore the correlation between serum homocysteine (HCY) levels and the methylene tetrahydrofolate reductase (MTHFR) gene 677C/T polymorphism and coronary heart disease (CHD). We consecutively enrolled 208 patients with CHD confirmed by CTA or coronary angiography from our hospital. An additional 200 healthy volunteers were enrolled as the control group. Serum HCY levels, MTHFR C677T genotype, and other related indicators were evaluated for the two groups. Compared to those in the control group, the serum HCY levels in the CHD patients were significantly higher (P < 0.05). The proportion of individuals with the heterozygous MTHFR CT genotype and homozygous mutant TT genotype among CHD patients was significantly higher than that in the control group (P < 0.05). In the acute coronary syndrome (ACS) subgroup, the proportion of those with the CT and TT genotypes was significantly higher than that of the stable CHD subgroup (P < 0.05). In summary, serum HCY levels were elevated in CHD patients, and the frequency of the CT and TT genotypes were also significantly increased, especially among the ACS subgroup. Taken together, this suggests that serum HCY levels and MTHFR C677T genotypes are correlated with CHD. PMID:27051002

  7. Methylenetetrahydrofolate Reductase C677T Polymorphism and Type 2 Diabetes Mellitus in Chinese Population: A Meta-Analysis of 29 Case-Control Studies

    PubMed Central

    Zhu, Bo; Wu, Xiaomei; Zhi, Xueyuan; Liu, Lei; Zheng, Quanmei; Sun, Guifan

    2014-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, had significant effects on the homocysteine levels. The common functional MTHFR C677T polymorphism had been extensively researched. Several studies had evaluated the relationship between MTHFR C677T polymorphism and type 2 diabetes mellitus (T2DM), but the results were still controversial in the Chinese Han population. This meta-analysis was conducted to evaluate the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. Methods We searched the relevant studies in multiple electronic databases, which published up to December 2013. We reviewed and extracted data from all the included studies on the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The odds ratios (ORs) and their 95% confidence intervals (95%CIs) were used to evaluate the relationship. Fixed-effects and random-effects meta-analysis were used to pool ORs by the heterogeneity. Publication bias and sensitivity analysis were also examined. Results 29 studies were finally included in our meta-analysis, which contained 4656 individuals with T2DM and 2127 healthy controls. There was a significant relationship between MTHFR C677T polymorphism and T2DM under dominant (OR: 1.70, 95% CI: 1.42–2.02), recessive (OR: 1.48, 95% CI: 1.21–1.80), homozygous (OR: 1.89, 95% CI: 1.47–2.42), heterozygous (OR: 1.58, 95% CI: 1.33–1.87), and additive (OR: 1.46, 95% CI: 1.28–1.68) genetic model in a random-effects model. Subgroup analysis also reached similar results. Sensitivity analysis indicated that the overall result were dependable. Conclusions There was a significant relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The results of our meta-analysis suggested that MTHFR 677T allele might be a risk genetic factor of T2DM in the Chinese Han population. PMID:25047451

  8. Quinone Reductase 2 Is a Catechol Quinone Reductase

    SciTech Connect

    Fu, Yue; Buryanovskyy, Leonid; Zhang, Zhongtao

    2008-09-05

    The functions of quinone reductase 2 have eluded researchers for decades even though a genetic polymorphism is associated with various neurological disorders. Employing enzymatic studies using adrenochrome as a substrate, we show that quinone reductase 2 is specific for the reduction of adrenochrome, whereas quinone reductase 1 shows no activity. We also solved the crystal structure of quinone reductase 2 in complexes with dopamine and adrenochrome, two compounds that are structurally related to catecholamine quinones. Detailed structural analyses delineate the mechanism of quinone reductase 2 specificity toward catechol quinones in comparison with quinone reductase 1; a side-chain rotational difference between quinone reductase 1 and quinone reductase 2 of a single residue, phenylalanine 106, determines the specificity of enzymatic activities. These results infer functional differences between two homologous enzymes and indicate that quinone reductase 2 could play important roles in the regulation of catecholamine oxidation processes that may be involved in the etiology of Parkinson disease.

  9. Effect of MTHFR Gene Polymorphism Impact on Atherosclerosis via Genome-Wide Methylation

    PubMed Central

    Lin, Xuefeng; Zhang, Wei; Lu, Qun; Lei, Xinjun; Wang, Tingzhong; Han, Xuanmao; Ma, Aiqun

    2016-01-01

    Background Atherosclerosis seriously threats human health. Homocysteine is an independent risk factor closely related to DNA methylation. MTHFR C667T loci polymorphism is closely associated with homocysteine level. This study aimed to investigate the relationship among MTHFR C667T loci polymorphism, genome-wide methylation, and atherosclerosis. Material/Methods Blood sample was collected from 105 patients with coronary atherosclerosis and 105 healthy controls. Pyrosequencing methylation was used to detect LINE-1 methylation level. Polymerase chain reaction-restriction enzyme fragment length polymorphism (PCR-RFLP) was used to test MTHFR. Results LINE-1 methylation level in the patient group was significantly lower than in the controls (t=5.007, P<0.001). MTHFR C667T genotype distribution presented marked differences in the 2 groups. TT genotype carriers had significantly increased risk of atherosclerosis (OR=3.56, P=0.009). Three different genotypes of MTHFR C667T loci showed different LINE-1 methylation level between the 2 groups (P<0.01). LINE-1 methylation level in TT and CT genotype carriers was obviously lower than in CC genotype carriers (P<0.05). Conclusions MTHFR C667T loci polymorphism may affect atherosclerosis by regulating genome methylation level. PMID:26828698

  10. Effect of multivitamins on plasma homocysteine in patients with the 5,10 methylenetetrahydrofolate reductase C677T homozygous state.

    PubMed

    Dell'edera, Domenico; Tinelli, Andrea; Milazzo, Giusi Natalia; Malvasi, Antonio; Domenico, Carone; Pacella, Elena; Pierluigi, Compagnoni; Giuseppe, Tarantino; Marcello, Guido; Francesco, Lomurno; Epifania, Annunziata Anna

    2013-08-01

    The role of hyperhomocysteinemia (HHcy) as a cardiovascular risk factor remains a matter of debate, while it correlates with folates, it demonstrates inverse correlation with plasma homocysteine (Hcy) levels and vitamin B12 levels and reduces plasma Hcy levels following supplementation with multivitamins. The purpose of this study was to demonstrate that administering multivitamins at specific doses for 90 days restores normal plasma Hcy levels in women who are homozygous for the thermolabile variant of 5,10 methylenetetrahydrofolate reductase (MTHFR C677T). We enrolled 106 healthy females aged between 30 and 42 years, who were non-smokers, non-vegetarian, normotensive and who had no history of food abuse in the previous months. Only females were enrolled in order to rule out any bias due to the variation in Hcy plasma concentrations between males and females. Patient blood sampling was performed in order to determine plasma Hcy, serum folic acid and vitamin B12 levels. Furthermore, molecular characterization of the C677T polymorphism present in the MTHFR gene, was also performed. The results of this study demonstrated that supplementation with specific multivitamins restores normal plasma Hcy levels, regardless of the MTHFR genotype. Furthermore, it is unnecessary to adminster high doses of folate to reduce plasma Hcy levels, and administering high doses of folate may cause pro-inflammatory and pro-proliferative effects. PMID:23818036

  11. Evaluation of the relationship between C677T variants of methylenetetrahydrofolate reductase gene and hyperhomocysteinemia in children receiving antiepileptic drug therapy.

    PubMed

    Vurucu, Sebahattin; Demirkaya, Erkan; Kul, Mustafa; Unay, Bulent; Gul, Davut; Akin, Ridvan; Gokçay, Erdal

    2008-04-01

    Homocysteine (Hcy) is a sulfur-containing amino acid involved in methionine metabolism. Elevated plasma Hcy concentration is a possible risk factor for vascular disease. Folate and vitamin B-12 are vitamins that are necessary for remethylization of Hcy to methionine. The methylenetetrahydrofolate reductase (MTHFR) is the key enzyme in remethylation of Hcy to methionine and supplies the required 5-methyltetrahydrofolate as the methyl donor for this reaction. It is well known that some antiepileptic drugs (AED) can lead to hyperhomocysteinemia by affecting the levels of folate and vitamin B-12. The C677T variant of MTHFR gene can also lead to hyperhomocysteinemia particularly when serum folate level is decreased. In this study, we investigated the levels of serum folate, vitamin B-12 and Hcy in epileptic patients receiving carbamazepine (CBZ) or valproic acid (VPA) as monotherapy, and we also evaluated the probable contribution of the C677T variant of MTHFR gene in hyperhomocysteinemia. A total of 93 patients with idiopathic epilepsy receiving CBZ or VPA as monotherapy were included in this study. CBZ and VPA groups consisted of 29 and 64 patients, respectively. The control group comprised 62 healthy children. We measured serum folate, vitamin B-12 and Hcy levels in each group. We found that mean serum folate level was statistically lower and mean Hcy level was higher in epileptic patients receiving CBZ or VPA when compared with those of controls'. We also determined the C677T variants of MTHFR gene (as normal, heterozygote or homozygote) in epileptic patients. We compared the variant groups for serum folate, vitamin B-12 and Hcy levels and found no significant differences among them. In conclusion, C677T variants of MTHFR gene have no contribution in hyperhomocysteinemia in epileptic patients receiving CBZ or VPA. PMID:18234410

  12. C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase gene: effect on methotrexate-related toxicity in adult acute lymphoblastic leukaemia.

    PubMed

    Eissa, Deena Samir; Ahmed, Tamer Mohamed

    2013-03-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme involved in folate metabolism. Two polymorphisms, C677T and A1298C, were described leading to reduced enzyme activity. Methotrexate (MTX) is an antifolate agent of consolidation and maintenance therapy of acute lymphoblastic leukaemia (ALL). Despite its clinical success, MTX can be associated with serious toxicities resulting in treatment interruption or discontinuation, impacting disease outcome. There is evidence that MTX toxicity can be affected by polymorphisms in genes encoding for drug-metabolizing enzymes such as MTHFR. Therefore, we aimed to investigate the influence of MTHFR C677T and A1298C polymorphisms on the frequency of MTX-related toxicity, disease outcome and patients' survival. MTHFR polymorphisms were assessed in 50 adult patients with de novo ALL using real-time PCR. Patients were followed-up for the development of haematologic and/or nonhaematologic toxicity and assessment of clinical outcome. Frequency of C677T polymorphisms was 42% for TT, 24% for CT and 34% for CC; A1298C polymorphisms were 28, 6 and 66% for CC, AC and AA, respectively. MTX therapy was significantly associated with neutropaenia, hepatic and gastrointestinal toxicities, unfavourable response at day 14 of induction therapy, increased relapse and mortality rates and shorter survival in patients with 677 TT genotype than in those with CC and CT, whereas 1298 CC genotype patients had lower frequency of neutropaenia, hepatic toxicity and relapse than in those with AA and AC. Our study suggests MTHFR polymorphism as an attractive predictor of MTX-related toxicity in adult ALL, considering it a potential prognostic factor influencing disease outcome. PMID:23183238

  13. Plasma homocysteine levels, methylene tetrahydrofolate reductase A1298C gene polymorphism and risk of retinal vein thrombosis.

    PubMed

    Ghaznavi, Habib; Soheili, Zahra; Samiei, Shahram; Soltanpour, Mohammad Soleiman

    2016-09-01

    There are limited data regarding the role of methylene tetrahydrofolate reductase (MTHFR) A1298C polymorphism and hyperhomocysteinemia as risk factors for retinal vein thrombosis (RVT) in Iranians. This study aimed to examine a possible association between fasting plasma total homocysteine (tHcy) levels, MTHFR A1298C polymorphism and RVT development in Iranian patients. Our study population consisted of 73 patients with a diagnosis of RVT (52.7 ± 16.2 years) and 73 age and sex-matched healthy controls (49.1 ± 14.6 years). Genotyping for the MTHFR A1298Cpolymorphism was conducted by PCR-RFLP technique and plasma tHcy levels were measured by an enzyme immunoassay method. Fasting plasma tHcy levels were 20.29 ± 8.5 μmol/l in RVT patients and 10.9 ± 3.1 μmol/l in control subjects. The number of cases with abnormal tHcy values (hyperhomocysteinemia) was significantly higher in the RVT patients than control subjects (P = 0.0001). The prevalence of MTHFR 1298CC homozygote genotype was similar in RVT patients and controls (17.8 vs.15.1%, P = 0.45). There were no significant differences in genotype distribution of MTHFR A1298C polymorphism between males and females in both RVT patients and controls (P > 0.05). The frequency of the 1298C allele was 39.1 and 35.6% in patients and controls, respectively, and did not differ significantly between them (P = 0.23). Moreover, heterozygote and homozygote genotypes in the RVT patients had significantly higher abnormal tHcy values than corresponding genotypes in control subjects (P < 0.001). Our study demonstrated that hyperhomocysteinemia but not homozygosity for MTHFR A1298C polymorphism is a significant risk factor for RVT in the Iranian population. PMID:26650461

  14. Association between the methylenetetrahydrofolate reductase c.677C>T polymorphism and bone mineral density: an updated meta-analysis.

    PubMed

    Li, Hong-Zhuo; Wang, Wei; Liu, Yi-Ling; He, Xiao-Feng

    2016-02-01

    Many studies have reported an association between the methylenetetrahydrofolate reductase (MTHFR) c.677C>T polymorphism and reduced bone mineral density (BMD), but results have been inconsistent. We, therefore, performed a meta-analysis to further explore this association. Twenty-one studies, comprising 33,045 subjects, analyzed the association of MTHFR c.677C>T with femoral neck BMD. Significant association with reduced BMD was observed in Caucasians (recessive model: WMD = -0.004 g/cm(2), 95 % CI -0.008 to -0.006), post-menopausal women (recessive model: WMD = -0.005 g/cm(2), 95 % CI -0.007 to -0.003), men (dominant model: WMD = -0.004 g/cm(2), 95 % CI -0.005 to -0.004; recessive model: WMD = -0.004 g/cm(2), 95 % CI -0.005 to -0.004; TT vs. CC: WMD = -0.006 g/cm(2), 95 % CI -0.006 to -0.006; CT vs. CC: WMD = -0.003 g/cm(2), 95 % CI -0.003 to -0.003), and cohort studies (recessive model: WMD = -0.003 g/cm(2), 95 % CI -0.006 to -0.001). Twenty-two studies, which included 32,271 subjects, analyzed the MTHFR c.677C>T association with lumbar spine BMD. Significant association with reduced BMD was observed in Caucasians, women, post-menopausal women, men, and cohort studies. Seven studies, comprising 6806 subjects, analyzed the MTHFR c.677C>T association with total hip BMD, but no significant association was observed in any population. Nine studies involving 5591 subjects analyzed the association with total body BMD. Significant association with reduced BMD was observed in overall and women subgroup analyses. In summary, this meta-analysis indicates that the MTHFR c.677C>T polymorphism is associated with reduced BMD in lumbar spine and femoral neck in Caucasians, post-menopausal women, and men, and with total body BMD in women. In addition, our results suggest that new studies examining the association between MTHFR c.677C>T polymorphism and BMD of lumbar spine and femoral neck in Asians is warranted, because I (2) > 75.0 % was observed

  15. [Polymorphism of genes coding for angiotensin I converting enzyme and methylenetetrahydrofolate reductase in patients with ischemic heart disease].

    PubMed

    Goracy, I

    2000-01-01

    Due to its multifarious biological activity the renin-angiotensin system occupies a special position among risk factors of ischemic heart disease. The discovery of I/D polymorphism of the ACE gene led to a better understanding of genetic control of this enzyme. Hyperhomocysteinemia is an independent risk factor of ischemic heart disease. Elevated plasma levels of homocysteine may be due to improper diet (e.g. shortage of folic acid) and/or genetic influence. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of homocysteine. The present study was performed in 100 patients (14 women and 86 men, mean age 54.2 +/- 9.2 years) with a history of myocardial infarction. The control group included 100 patients (10 women and 90 men, mean age 52.3 +/- 10 years) without such history. PCR was used to detect I/D ACE and C677T MTHFR polymorphisms. Genomic DNA was isolated from peripheral blood nuclear cells and amplified by PCR with two pairs of primers flanking the polymorphic regions. The restriction enzyme Hinf I was used to identify genotypes of the MTHFR polymorphism. No difference between both groups was found concerning the distribution of I/D ACE genotypes (31% II, 51% ID, 18% DD in the study group; 30% II, 57% ID, 13% DD in the control group; Tab. 1) or the distribution of C677T MTHFR genotypes (46% CC, 45% CT, 9% TT in the study group; 39% CC, 50% CT, 11% TT in the control group; Tab. 2). There was a significant effect of I/D genotype on ACE activity (IU/L) in the study (II = 18.2 +/- 17.9; ID = 33.5 +/- 19.9; DD = 68.9 +/- 21.9) and in the control group (II = 24.2 +/- 18.1; ID = 31.5 +/- 20.9; DD = 51.4 +/- 19.5; Tab. 3). No correlation was confirmed between ACE or MTHFR genotypes and age at infarction or left ventricular mass (Tabs. 4, 5, 6). The results indicate that neither the I/D ACE nor the C677T MTHFR polymorphisms are associated with risk of myocardial infarction in the Polish population. PMID:11712321

  16. Association of the methylenetetrahydrofolate reductase gene C677T polymorphism with the risk of male infertility: a meta-analysis.

    PubMed

    Zhu, Xudong; Liu, Zhiguo; Zhang, Maochen; Gong, Ruihong; Xu, Yajun; Wang, Baoming

    2016-03-01

    Several molecular epidemiological studies have been conducted to examine the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and male infertility susceptibility, but the results remain inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. In this meta-analysis, a total of 26 case-control studies including 5659 infertility cases and 5528 controls were selected to evaluate the possible association. The pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were used to assess the strength of association of C677T polymorphism with male infertility in the additive model, dominant model, recessive model and allele-frequency genetic model. In the overall analysis, the frequency of the 677T allele was significantly associated with male infertility susceptibility (OR = 2.32, 95%CI = 2.04-2.65 for TT vs. CC genotype; OR = 1.09, 95%CI = 1.00-1.19 for CT vs. CC genotype; OR = 1.19, 95%CI = 1.10-1.29 for CT/TT vs. CC genotype; OR = 1.54, 95%CI = 1.36-1.74 for TT vs. CC/TT genotype; OR = 1.22, 95%CI = 1.15-1.30 for T vs. C allele). A subgroup analysis of the subjects showed that significantly strong association between MTHFR C677T polymorphism and male infertility was present only in Asians, but not in Caucasians. Additionally, MTHFR C677T was associated with a significant increase in the risk of azoospermia in all genetic models. Meanwhile, no significantly increased risks of oligoasthenotertozoospermia (OAT) were found in most of the genetic models. In conclusion, this meta-analysis is in favor that the MTHFR C677T polymorphism is capable of causing male infertility susceptibility, especially in Asians and the subgroup of azoospermia. PMID:26584688

  17. Folate Intake at RDA Levels Is Inadequate for Mexican American Men with the Methylenetetrahydrofolate Reductase 677TT Genotype123

    PubMed Central

    Solis, Claudia; Veenema, Kristin; Ivanov, Alexandre A.; Tran, Sally; Li, Rui; Wang, Wei; Moriarty, David J.; Maletz, Charles V.; Caudill, Marie A.

    2009-01-01

    Since the establishment of the 1998 folate recommended dietary allowance (RDA), the methylenetetrahydrofolate reductase (MTHFR) 677C→T variant has emerged as a strong modifier of folate status. This controlled feeding study investigated the adequacy of the RDA, 400 μg/d as dietary folate equivalents (DFE), for Mexican American men with the MTHFR 677CC or TT genotype. Because of the interdependency between folate and choline, the influence of choline intake on folate status was also assessed. Mexican American men (n = 60; 18–55 y) with the MTHFR 677CC (n = 31) or TT (n = 29) genotype consumed 438 μg DFE/d and total choline intakes of 300, 550 (choline adequate intake), 1100, or 2200 mg/d for 12 wk. Folate status response was assessed via serum folate (SF), RBC folate, plasma total homocysteine (tHcy), and urinary folate. SF decreased (P < 0.001) 66% to 7.9 ± 0.7 nmol/L (means ± SEM) in men with the 677TT genotype and 62% to 11.3 ± 0.9 nmol/L in the 677CC genotype. Plasma tHcy increased (P < 0.0001) 170% to 31 ± 3 μmol/L in men with the 677TT genotype and 18% to 11.6 ± 0.3 μmol/L in the 677CC genotype. At the end of the study, 34% (677TT) and 16% (677CC) had SF concentrations <6.8 nmol/L and 79% (677TT) and 7% (677CC) had tHcy concentrations >14 μmol/L. Choline intake did not influence the response of the measured variables. These data showed that the folate RDA is not adequate for men of Mexican descent, particularly for those with the MTHFR 677TT genotype, and demonstrated a lack of influence of choline intake on the folate status variables measured in this study. PMID:18156406

  18. 5,10-Methylenetetrahydrofolate reductase codon 677 and 1298 polymorphisms and colon cancer in African Americans and whites.

    PubMed

    Keku, Temitope; Millikan, Robert; Worley, Kendra; Winkel, Scott; Eaton, Allison; Biscocho, Lorna; Martin, Christopher; Sandler, Robert

    2002-12-01

    We evaluated polymorphisms in methylenetetrahydrofolate reductase (MTHFR), folate intake and alcohol consumption in relation to risk of colon cancer in a population-based case-control study in North Carolina. The study included 555 cases (244 African Americans and 311 whites) and 875 controls (331 African Americans and 544 whites). Total folate intake of <400 versus > or =400 microg/day showed a weak positive association with colon cancer among both African Americans [adjusted odds ratio (OR) = 1.4, 95% confidence interval (CI) = 1.0-2.0] and whites (OR = 1.6, 95% CI = 1.2-2.2). No association was observed with use of alcohol. Compared with wild-type genotypes, there was no association between the low activity MTHFR codon 677 TT genotype and colon cancer, but the low activity codon 1298 CC genotype was inversely associated with colon cancer in whites (OR = 0.5, 95% CI = 0.3-0.9). Unlike previous studies, we did not observe a strong protective effect of the codon 677 TT low-activity genotype when folate intake was high. Instead, we observed an increased risk of colon cancer when folate intake was low for participants with wild- type genotypes. Adjusted ORs for the combined effects of codon 677 CC and codon 1298 AA genotypes and folate intake <400 microg/day were 1.9 (95% CI = 1.1-3.4) in African Americans and 2.5 (95% CI = 1.2-5.2) in whites. Our results suggest that variation at MTHFR codon 1298 (within the COOH-terminal region) may be more important for colon cancer than variation at codon 677 (NH(2)-terminal region), and in populations where folate intake is low, wild-type MTHFR activity may increase risk for colon cancer. PMID:12496052

  19. No Association of Functional Polymorphisms in Methlylenetetrahydrofolate Reductase and the Risk and Minor Physical Anomalies of Schizophrenia in Korean Population

    PubMed Central

    Kim, Su-Gyeong; Song, Joo Yun; Joo, Eun-Jeong; Jeong, Seong Hoon; Kim, Se Hyun; Lee, Kyu Young; Lee, Nam Young; Ahn, Yong Min; Kim, Yong Sik

    2011-01-01

    Methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in folate metabolism, plays an important role in DNA methylation. It has been suggested that abnormal DNA methylation contributes to the pathogenesis of schizophrenia and congenital anomalies. The previous findings regarding the genetic relationship between MTHFR and schizophrenia are controversial. This study investigated the association of the two functional polymorphisms of MTHFR, C677T and A1298C, with the risk for schizophrenia. Furthermore, we conducted an updated meta-analysis on the two polymorphisms. In addition, we investigated the relationship between the polymorphisms and minor physical anomaly (MPA), which may represent neurodevelopmental aberrations in 201 schizophrenia patients and 350 normal control subjects. There was no significant association between either of the two polymorphisms and the risk of schizophrenia (chi-square = 0.001, df = 1, P = 0.971 for C677T; chi-square = 1.319, df = 1, P = 0.251 for A1298C). However, in meta-analysis, the C677T polymorphism showed a significant association in the combined and Asian populations (OR = 1.13, P = 0.005; OR = 1.21, P = 0.011, respectively) but not in the Korean and Caucasian populations alone. Neither polymorphism was associated with MPAs measured by the Waldrop scale (chi-square = 2.513, df = 2, P = 0.285). In conclusion, the present findings suggest that in the Korean population, the MTHFR polymorphisms are unlikely to be associated with the risk for schizophrenia and neurodevelopmental abnormalities related to schizophrenia. PMID:22022190

  20. Association between a microRNA-214 binding site polymorphism in the methylenetetrahydrofolate reductase gene and esophageal squamous cell carcinoma.

    PubMed

    Shen, G R; Li, W Z; Liu, Y C; Li, X P; Yuan, H Y

    2016-01-01

    MicroRNAs (miRNAs) are key regulators of gene expression and play an important role in the development and progression of various diseases including esophageal squamous cell carcinoma (ESCC). In this study, we determined whether a polymorphism at the miR-214 binding site in the 3'-untranslated region (3'-UTR) of the methylenetetrahydrofolate reductase gene (MTHFR) is associated with susceptibility to ESCC. A total of 448 ESCC cases and 460 gender- and age-matched subjects were recruited for the study. The genotypes of the rs114673809 single nucleotide polymorphism (SNP) were determined by polymerase chain reaction sequencing. Associations between genotypes of MTHFR rs114673809 and ESCC risk were determined using logistic regression analyses. In the recessive model, when the MTHFR rs114673809 GG homozygote genotype was used as the reference group, the GA genotype was not associated with the risk of ESCC (GA vs GG: OR = 1.261, 95%CI = 0.960-1.657, P = 0.110), but the AA genotype was associated with increased risk of ECSS (AA vs GG: OR = 1.752, 95%CI = 1.076-2.853, P = 0.027). Additionally, the rs114673809 A allele carriers also showed a 1.286-fold increased ESCC risk compared with those carrying the rs114673809 G allele genotype. Furthermore, we observed a significant increase in plasma homocysteine levels in ESCC cases carrying the AA genotype relative to ESCC cases carrying the GG genotype. Our data demonstrate that a polymorphism at the miR-214 binding site in the 3'-UTR of MTHFR is an ESCC susceptibility SNP in the Chinese population. PMID:27323028

  1. Strong Association of 677 C>T Substitution in the MTHFR Gene with Male Infertility - A Study on an Indian Population and a Meta-Analysis

    PubMed Central

    Gupta, Nishi; Gupta, Saraswati; Dama, Madhukar; David, Archana; Khanna, Geeta; Khanna, Anil; Rajender, Singh

    2011-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme of folate and methionine metabolism, making it crucial for DNA synthesis and methylation. The objective of this study was to analyze MTHFR gene 677C>T polymorphism in infertile male individuals from North India, followed by a meta-analysis on our data and published studies. Methodology/Principal Findings We undertook genotyping on a total of 837 individuals including well characterized infertile (N = 522) and confirmed fertile (N = 315) individuals. The SNP was typed by direct DNA sequencing. Chi square test was done for statistical analysis. Published studies were searched using appropriate keywords. Source of data collection for meta-analysis included ‘Pubmed’, ‘Ovid’ and ‘Google Scholar’. Those studies analyzing 677C>T polymorphism in male infertility and presenting all relevant data were included in meta-analysis. The genotype data for infertile subjects and fertile controls was extracted from each study. Chi square test was done to obtain odds ratio (OR) and p-value. Meta-analysis was performed using Comprehensive Meta-analysis software (Version 2). The frequency of mutant (T) allele (p = 0.0025) and genotypes (CT+TT) (p = 0.0187) was significantly higher in infertile individuals in comparison to fertile controls in our case-control study. The overall summary estimate (OR) for allele and genotype meta-analysis were 1.304 (p = 0.000), 1.310 (p = 0.000), respectively, establishing significant association of 677C>T polymorphism with male infertility. Conclusions/Significance 677C>T substitution associated strongly with male infertility in Indian population. Allele and genotype meta-analysis also supported its strong correlation with male infertility, thus establishing it as a risk factor. PMID:21799811

  2. High-dose folic acid supplementation alters the human sperm methylome and is influenced by the MTHFR C677T polymorphism.

    PubMed

    Aarabi, Mahmoud; San Gabriel, Maria C; Chan, Donovan; Behan, Nathalie A; Caron, Maxime; Pastinen, Tomi; Bourque, Guillaume; MacFarlane, Amanda J; Zini, Armand; Trasler, Jacquetta

    2015-11-15

    Dietary folate is a major source of methyl groups required for DNA methylation, an epigenetic modification that is actively maintained and remodeled during spermatogenesis. While high-dose folic acid supplementation (up to 10 times the daily recommended dose) has been shown to improve sperm parameters in infertile men, the effects of supplementation on the sperm epigenome are unknown. To assess the impact of 6 months of high-dose folic acid supplementation on the sperm epigenome, we studied 30 men with idiopathic infertility. Blood folate concentrations increased significantly after supplementation with no significant improvements in sperm parameters. Methylation levels of the differentially methylated regions of several imprinted loci (H19, DLK1/GTL2, MEST, SNRPN, PLAGL1, KCNQ1OT1) were normal both before and after supplementation. Reduced representation bisulfite sequencing (RRBS) revealed a significant global loss of methylation across different regions of the sperm genome. The most marked loss of DNA methylation was found in sperm from patients homozygous for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, a common polymorphism in a key enzyme required for folate metabolism. RRBS analysis also showed that most of the differentially methylated tiles were located in DNA repeats, low CpG-density and intergenic regions. Ingenuity Pathway Analysis revealed that methylation of promoter regions was altered in several genes involved in cancer and neurobehavioral disorders including CBFA2T3, PTPN6, COL18A1, ALDH2, UBE4B, ERBB2, GABRB3, CNTNAP4 and NIPA1. Our data reveal alterations of the human sperm epigenome associated with high-dose folic acid supplementation, effects that were exacerbated by a common polymorphism in MTHFR. PMID:26307085

  3. MTHFR 677C>T Polymorphism and the Risk of Breast Cancer: Evidence from an Original Study and Pooled Data for 28031 Cases and 31880 Controls

    PubMed Central

    Sekhar, Deepa; Francis, Amirtharaj; Gupta, Nishi; Konwar, Rituraj; Kumar, Sandeep; Kumar, Surender; Thangaraj, Kumarasamy; Rajender, Singh

    2015-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) acts at an important metabolic point in the regulation of cellular methylation reaction. It assists in the conversion of 5, 10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. The latter aids in remethylation of homocysteine to de novo methionine that is required for DNA synthesis. The objective of this study was to examine the effect of MTHFR 677 C>T polymorphism on the risk of breast cancer in the Indian sub-continent. Methods and Results We genotyped 677 C>T locus in 1096 individuals that were classified into cases (N=588) and controls (N=508). Genotype data were analyzed using chi-square test. No significant difference was observed in the distribution of genotypes between cases and controls in north Indian (P = 0.932), south Indian (P = 0.865), and pooled data (P = 0.680). To develop a consensus regarding the impact of 677C>T polymorphism on breast cancer risk, we also conducted a meta-analysis on 28031 cases and 31880 controls that were pooled from sixty one studies. The overall summary estimate upon meta-analysis suggested no significant correlation between the 677C>T substitution and breast cancer in the dominant model (Fixed effect model: OR = 0.97, P=0.072, Random effects model: OR = 0.96, P = 0.084) or the recessive model (Fixed effect model: OR = 1.05, P = 0.089; Random effects model: OR= 1.08, P= 0.067). Conclusion 677 C>T substitution does not affect breast cancer risk in the Indo-European and Dravidian populations of India. Analysis on pooled data further ruled out association between the 677 C>T polymorphism and breast cancer. Therefore, 677 C>T substitution does not appear to influence the risk of breast cancer. PMID:25803740

  4. Impact of Genetic Polymorphism of methylenetetrahydrofolate reductase C677T on Development of Hyperhomocysteinemia and Related Oxidative Changes in Egyptian β-Thalassemia Major Patients

    PubMed Central

    Abd-Elmawla, Mai A.; Rizk, Sherine M.; Youssry, Ilham; Shaheen, Amira A.

    2016-01-01

    Background β-thalasemia major (β-TM) patients often suffer from various vascular complications together with increased oxidative stress. Hyperhomocysteinemia (Hhcy) has been defined as a risk factor for these complications. Genetic polymorphism of methylenetetrahydrofolate reductase (MTHFR) C677T has been shown to cause Hhcy particularly in individuals with low B-vitamins. However, the status of homocysteine (hcy) in β-TM has not yet been adequately defined. Aim To evaluate the genetic polymorphism of MTHFR C677T among β-TM patients and its prospective contribution to Hhcy and related oxidative changes. Subjects and Methods Genotyping for MTHFR C677T was done by PCR-RFLP technique. Plasma hcy, vitamin B12, folate, malondialdehyde (MDA), total antioxidant capacity (TAC), oxidized low density lipoprotein (oxLDL), total nitric oxide (NOx) and lipid profile were determined in 66 β-TM patients and 66 control subjects of matched age and sex. Results The prevalence of MTHFR 677TT genotype was significant among β-TM patients (12%) compared to (3%) controls (OR = 4.9, 95%CI:1.2–24.2,P = 0.03). A strong association between Hhcy and MTHFR TT genotype was observed (OR = 7.7, 95%CI:2.8–20.9) where all β-TM patients with TT genotype were hyperhomocystienemic (≥ 15 μmol/l) and having sub-optimal folate level than those with CT or CC genotypes. Hyperhomocystienemic patients have suffered from increased oxidative stress characterized by significant increase in plasma MDA and oxLDL, and a significant reduction of plasma TAC and total NOx. Lipid profile of those patients was severely affected indicated by reduction in HDL and HDL/LDL and elevation in atherogenic index as compared with CC genotype. Other measured parameters were not significantly different among β-TM patients with different MTHFR genotypes. Conclusion This study suggests that Egyptian β-TM patients with MTHFR 677TT genotype could be at increasing risk of developing Hhcy particularly with folate

  5. Identification of a functional SNP in the 3'-UTR of caprine MTHFR gene that is associated with milk protein levels.

    PubMed

    An, Xiaopeng; Song, Yuxuan; Hou, Jinxing; Wang, Shan; Gao, Kexin; Cao, Binyun

    2016-08-01

    Xinong Saanen (n = 305) and Guanzhong (n = 317) dairy goats were used to detect SNPs in the caprine MTHFR 3'-UTR by DNA sequencing. One novel SNP (c.*2494G>A) was identified in the said region. Individuals with the AA genotype had greater milk protein levels than did those with the GG genotype at the c.*2494 G>A locus in both dairy goat breeds (P < 0.05). Functional assays indicated that the MTHFR:c.2494G>A substitution could increase the binding activity of bta-miR-370 with the MTHFR 3'-UTR. In addition, we observed a significant increase in the MTHFR protein level of AA carriers relative to that of GG carriers. These altered levels of MTHFR protein may account for the association of the SNP with milk protein level. PMID:27062401

  6. Association Between MTHFR Genetic Variants and Multiple Sclerosis in a Southern Iranian Population

    PubMed Central

    Naghibalhossaini, Fakhraddin; Ehyakonandeh, Hesam; Nikseresht, Alireza; Kamali, Eskandar

    2015-01-01

    Multiple sclerosis (MS) is a demyelinating neuro- inflammatory autoimmune disease of the central nervous system. Genetic predisposition has long been suspected in the etiology of this disease. The association between MTHFR polymorphisms and MS has been ivestigated in different ethnic groups. We investigated the association between MTHFR C677T and A1298C missense variants and MS in 180 patients and 231 age- and gender-matched healthy controls in a Southern Iranian population. The mutagenically separated PCR (MS-PCR) and PCR-RFLP methods were used to genotype MTHFR at position 677 and 1298, respectively. Compared with controls, we observed a strong association between two MTHFR variants and the risk of developing MS. Subjects carrying 677T allele (CT and TT genotypes) had increased susceptibility to MS as compared to those carrying CC genotype (odds ratio (OR) for CT= 2.9, 95% confidence interval (95% CI)= 1.88-4.49; OR for TT= 6.23, 95% CI= 3.08-12.59). The variant 1298AC genotype also increased the risk for MS among our study population (OR= 2.14, 95% CI= 1.37-3.34). Combined genotype analysis for two MTHFR SNPs revealed that compared to the wild type genotypes (677CC/1298AA), 3 genotypes including TT/AC, CT/AC, and TT/AA were significantly at increased risk for MS development (OR= 13.9, 5.3, and 4.9, respectively). Our results suggest a possible gene dose- dependent association between MTHFR mutrant alleles and the risk of MS development. PMID:26261797

  7. Association Between MTHFR Genetic Variants and Multiple Sclerosis in a Southern Iranian Population.

    PubMed

    Naghibalhossaini, Fakhraddin; Ehyakonandeh, Hesam; Nikseresht, Alireza; Kamali, Eskandar

    2015-01-01

    Multiple sclerosis (MS) is a demyelinating neuro- inflammatory autoimmune disease of the central nervous system. Genetic predisposition has long been suspected in the etiology of this disease. The association between MTHFR polymorphisms and MS has been ivestigated in different ethnic groups. We investigated the association between MTHFR C677T and A1298C missense variants and MS in 180 patients and 231 age- and gender-matched healthy controls in a Southern Iranian population. The mutagenically separated PCR (MS-PCR) and PCR-RFLP methods were used to genotype MTHFR at position 677 and 1298, respectively. Compared with controls, we observed a strong association between two MTHFR variants and the risk of developing MS. Subjects carrying 677T allele (CT and TT genotypes) had increased susceptibility to MS as compared to those carrying CC genotype (odds ratio (OR) for CT= 2.9, 95% confidence interval (95% CI)= 1.88-4.49; OR for TT= 6.23, 95% CI= 3.08-12.59). The variant 1298AC genotype also increased the risk for MS among our study population (OR= 2.14, 95% CI= 1.37-3.34). Combined genotype analysis for two MTHFR SNPs revealed that compared to the wild type genotypes (677CC/1298AA), 3 genotypes including TT/AC, CT/AC, and TT/AA were significantly at increased risk for MS development (OR= 13.9, 5.3, and 4.9, respectively). Our results suggest a possible gene dose- dependent association between MTHFR mutrant alleles and the risk of MS development. PMID:26261797

  8. MTHFR polymorphisms and cognitive ageing in the ninth decade: the Lothian Birth Cohort 1921.

    PubMed

    Schiepers, O J G; van Boxtel, M P J; Harris, S E; Gow, A J; Pattie, A; Brett, C E; de Groot, R H M; Jolles, J; Starr, J M; Deary, I J

    2011-04-01

    Low blood levels of B vitamins have been implicated in age-associated cognitive impairment. The present study investigated the association between genetic variation in folate metabolism and age-related cognitive decline in the ninth decade of life. Both the 677C>T (rs1801133) polymorphism and the scarcely studied 1298A>C (rs1801131) polymorphism of the MTHFR gene were assessed in relation to cognitive change over 8 years in older community-dwelling individuals. MTHFR genotype was determined in 476 participants of the Lothian Birth Cohort 1921, whose intelligence was measured in childhood in the Scottish Mental Survey of 1932. Cognitive performance on the domains of verbal memory, reasoning and verbal fluency was assessed at mean age of 79 (n = 476) and again at mean ages of 83 (n = 275) and 87 (n = 180). Using linear mixed models, the MTHFR 677C>T and 1298A>C variants were not associated with the rate of cognitive change between 79 and 87 years, neither in the total sample, nor in a subsample of individuals with erythrocyte folate levels below the median. APOE E4 allele carrier status did not interact with MTHFR genotype in affecting change in cognitive performance over 8 years. No significant combined effect of the two polymorphisms was found. In conclusion, MTHFR 677C>T and 1298A>C polymorphisms were not associated with individual change in cognitive functioning in the ninth decade of life. Although polymorphisms in the MTHFR gene may cause disturbances in folate metabolism, they do not appear to be accompanied by changes in cognitive functioning in old age. PMID:21255267

  9. Aldose and aldehyde reductases : structure-function studies on the coenzyme and inhibitor-binding sites.

    SciTech Connect

    El-Kabbani, O.; Old, S. E.; Ginell, S. L.; Carper, D. A.; Biosciences Division; Monash Univ.; NIH

    1999-09-03

    PURPOSE: To identify the structural features responsible for the differences in coenzyme and inhibitor specificities of aldose and aldehyde reductases. METHODS: The crystal structure of porcine aldehyde reductase in complex with NADPH and the aldose reductase inhibitor sorbinil was determined. The contribution of each amino acid lining the coenzyme-binding site to the binding of NADPH was calculated using the Discover package. In human aldose reductase, the role of the non-conserved Pro 216 (Ser in aldehyde reductase) in the binding of coenzyme was examined by site-directed mutagenesis. RESULTS: Sorbinil binds to the active site of aldehyde reductase and is hydrogen-bonded to Trp 22, Tyr 50, His 113, and the non-conserved Arg 312. Unlike tolrestat, the binding of sorbinil does not induce a change in the side chain conformation of Arg 312. Mutation of Pro 216 to Ser in aldose reductase makes the binding of coenzyme more similar to that of aldehyde reductase. CONCLUSIONS: The participation of non-conserved active site residues in the binding of inhibitors and the differences in the structural changes required for the binding to occur are responsible for the differences in the potency of inhibition of aldose and aldehyde reductases. We report that the non-conserved Pro 216 in aldose reductase contributes to the tight binding of NADPH.

  10. Effects of thioredoxin reductase-1 deletion on embryogenesis and transcriptome

    PubMed Central

    Bondareva, Alla A.; Capecchi, Mario R.; Iverson, Sonya V.; Li, Yan; Lopez, Nathan I.; Lucas, Olivier; Merrill, Gary F.; Prigge, Justin R.; Siders, Ashley M.; Wakamiya, Maki; Wallin, Stephanie L.; Schmidt, Edward E.

    2007-01-01

    Thioredoxin reductases (Txnrd)1 maintain intracellular redox homeostasis in most organisms. Metazoans Txnrds also participate in signal transduction. Mouse embryos homozygous for a targeted null mutation of the txnrd1 gene, encoding the cytosolic thioredoxin reductase, were viable at embryonic day 8.5 (E8.5) but not at E9.5. Histology revealed that txnrd1−/− cells were capable of proliferation and differentiation; however, mutant embryos were smaller than wild-type littermates and failed to gastrulate. In situ marker gene analyses indicated primitive streak mesoderm did not form. Microarray analyses on E7.5 txnrd−/− and txnrd+/+ littermates showed similar mRNA levels for peroxiredoxins, glutathione reductases, mitochondrial Txnrd2, and most markers of cell proliferation. Conversely, mRNAs encoding sulfiredoxin, IGF-binding protein 1, carbonyl reductase 3, glutamate cysteine ligase, glutathione S-transferases, and metallothioneins were more abundant in mutants. Many gene expression responses mirrored those in thioredoxin reductase 1-null yeast; however mice exhibited a novel response within the peroxiredoxin catalytic cycle. Thus, whereas yeast induce peroxiredoxin mRNAs in response to thioredoxin reductase disruption, mice induced sulfiredoxin mRNA. In summary, Txnrd1 was required for correct patterning of the early embryo and progression to later development. Conserved responses to Txnrd1 disruption likely allowed proliferation and limited differentiation of the mutant embryo cells. PMID:17697936

  11. Prevalence of methylenetetrahydrofolate reductase 677 C-T polymorphism among mothers of Down syndrome children

    PubMed Central

    Kaur, Anupam; Kaur, Amandeep

    2013-01-01

    INTRODUCTION: The relationship between chromosomal non-disjunction leading to aneuploidy and folate metabolism has drawn attention in the recent years. In this study, we examined the polymorphism in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR), namely, 677 C-T in women having Down syndrome (DS) children. MATERIALS AND METHODS: The prevalence of these variant genotypes (MTHFR 677 C-T polymorphism) in women having DS children (case mothers) (n = 110) was compared with controls (n = 111) from Punjab. Genotyping was done using the polymerase chain reaction method followed by restriction fragment length polymorphism. RESULTS: In the present study, 1.8% of case mothers had TT genotype while none of the control mothers showed this genotype. T allele frequency among cases was 0.13 and 0.11 in controls. The Chi-square value showed a non-significant difference between cases and controls. CONCLUSION: No association has been observed between 677 C-T polymorphism and risk of non-disjunction in case mothers. Detection of polymorphisms in more genes of folate pathway is required to find out the exact cause of non-disjunction. PMID:24497705

  12. Detection of Thrombophilic Mutations Related to Spontaneous Abortions by a Multiplex SNaPshot Method

    PubMed Central

    Madjunkova, Svetlana; Volk, Marija; Peterlin, Borut

    2012-01-01

    Spontaneous abortion is a significant clinical problem of different etiologies. Certain thrombophilia gene mutations have been associated with an increased risk of spontaneous abortion. Also, mutations in folate-related genes can lead to abnormal chromosomal segregation during meiosis which is the most common cause of spontaneous abortion. We have developed a multiplex single-base extension reaction assay that allows simultaneous analysis of 10 different mutations in thrombophilia- and folate-related genes (Factor V Leiden G1691A, Factor V H1299R, Factor II G20210A, Factor XIII V34L, PAI-I -675 4G/5G, FGB -455G/A, MTHFR C677T, MTHFR A1298C, MTR A2756G, and MTRR A66G). Using this method we have studied 232 women who had a spontaneous abortion and 209 of their male partners. Prevalence of Factor II G20210A and Factor V H1299R mutations was significantly higher in the women than in their male partners (2.4% and 0.7%, respectively [p=0.0499] for the Factor II mutation and 9.3% and 5.7%, respectively [p=0.0485] for the Factor V mutation). The prevalence of MTHFR C677T, MTHFR A1298C, MTR A2756G, and MTRR A66G mutations did not differ between the studied groups. In conclusion, we have developed a rapid, simple, reliable, and inexpensive multiplex SNaPshot method for determination of 10 thrombophilic mutations that may result in spontaneous abortions. PMID:22023244

  13. [The different genotypes of MTHFR 1298A>C and PON1 -108C>T polymorphisms confer the increased risk of the abdominal aortic aneurysm in the smoking and nonsmoking persons].

    PubMed

    Strauss, Ewa; Waliszewski, Krzysztof; Pawlak, Andrzej L

    2005-01-01

    In abdominal aortic aneurysm (AAA) both the etiology and the pathogenesis are of the multifactorial character. The genetic component in the determination of this disease is proven by its familial occurrence. Smoking represents the best recognized risk factor of the AAA development. Increased concentrations of homocysteine (Hcy) in plasma are the common finding in these patients. It is assumed that the Hcy thiolactone, the most reactive metabolite of Hcy, may participate in the aortic wall destruction in AAA. The polymorphic variants of the methylenetetrahydrofolate reductase (MTHFR 677C>T and 1298A>C) influence tissue concentrations of the Hcy. Paraoxonase (PON1), the enzyme associated in plasma with the HDL fraction, as lactonase detoxicates the Hcy thiolactone. The promotor polymorphism of PON1 - 108C>T gene may determine the lower activity of this enzyme. In the case-control study of 106 patients with AAA and 97 healthy persons, the effects of selected genetic and nongenetic risk factors on development of AAA were assessed, considering the possibilities of interaction between them. It was found, that the arterial hypertension, cigarette smoking and the lower HDL fraction are independent risk factors of AAA. The arterial hypertension was a risk factor both in the smoking and the nonsmoking males, whereas the lower HDL fraction has been the risk factor only for the smoking men. By the multivariate analysis in the nonsmoking males the MTHFR 1298 AC and CC genotypes increased the risk of AAA development 4,8-fold in relation to the MTHFR 1298 AA nonsmoking males. In reference to the genotypes of the expected high impact on the metabolism of Hcy and of Hcy thiolactone, the genotypes of MTHFR 677TT and PON1 -108CT and TT were more frequent in smoking ones, but the difference was not significant. This observation fits with the assumption that the influence of smoking on the occurrence of AAA prevails over that of genetic variability. When the patients age was considered

  14. Association between premature ovarian failure, polymorphisms in MTHFR and MTRR genes and serum homocysteine concentration.

    PubMed

    Hou, Ningning; Chen, Songchang; Chen, Feng; Jiang, Minmin; Zhang, Junyu; Yang, Yanmei; Zhu, Bo; Bai, Xiaoxia; Hu, Yuting; Huang, Hefeng; Xu, Chenming

    2016-04-01

    This study investigated the association between premature ovarian failure (POF), MTHFR C677T/A1298C and MTRR A66G genotypes and serum homocysteine (Hcy) concentration. A prospective study was conducted in Chinese women, which included POF patients (n = 180) and controls (n = 195). Peripheral blood samples were used to determine MTHFR C677T/A1298C and MTRR A66G genotypes, and serum Hcy and sex hormone concentrations. Results showed that serum Hcy concentrations of POF patients were significantly higher than those of controls (P < 0.0001). In POF patients, serum Hcy concentrations were significantly correlated with oestradiol and FSH concentrations (r = -0.174, P = 0.037 and r = +0.238, P = 0.006, respectively). There were no significant differences in the distributions of MTHFR C677T/A1298C or MTRR A66G genotypes between the two groups. However, these genetic variants influenced serum Hcy concentrations in POF patients, especially for MTRR 66 AA/AG/GG genotypes, which were significantly correlated with the patients' Hcy concentrations (τ = 0.166, P = 0.033). These results suggest that serum Hcy concentrations in Chinese POF patients are increased and correlated with serum oestradiol/FSH concentrations. In conclusion, MTHFR C667T/A1298C and MTRR A66G genotypes are not associated with POF development, but they affect the patients' serum Hcy concentrations. PMID:26874989

  15. Flavodiiron Oxygen Reductase from Entamoeba histolytica

    PubMed Central

    Gonçalves, Vera L.; Vicente, João B.; Pinto, Liliana; Romão, Célia V.; Frazão, Carlos; Sarti, Paolo; Giuffrè, Alessandro; Teixeira, Miguel

    2014-01-01

    Flavodiiron proteins (FDPs) are a family of enzymes endowed with bona fide oxygen- and/or nitric-oxide reductase activity, although their substrate specificity determinants remain elusive. After a comprehensive comparison of available three-dimensional structures, particularly of FDPs with a clear preference toward either O2 or NO, two main differences were identified near the diiron active site, which led to the construction of site-directed mutants of Tyr271 and Lys53 in the oxygen reducing Entamoeba histolytica EhFdp1. The biochemical and biophysical properties of these mutants were studied by UV-visible and electron paramagnetic resonance (EPR) spectroscopies coupled to potentiometry. Their reactivity with O2 and NO was analyzed by stopped-flow absorption spectroscopy and amperometric methods. These mutations, whereas keeping the overall properties of the redox cofactors, resulted in increased NO reductase activity and faster inactivation of the enzyme in the reaction with O2, pointing to a role of the mutated residues in substrate selectivity. PMID:25151360

  16. Significance of 5,10-methylenetetrahydrofolate reductase gene variants in acute lymphoblastic leukemia in Indian population: an experimental, computational and meta-analysis.

    PubMed

    Bellampalli, Ravishankara; Phani, Nagaraja M; Bhat, Kamalakshi G; Prasad, Krishna; Bhaskaranand, Nalini; Guruprasad, Kanive P; Rai, Padmalatha S; Satyamoorthy, Kapaettu

    2015-05-01

    Acute lymphoblastic leukemia (ALL) arises due to several genetic alterations in progenitor cells, and methotrexate is frequently used as part of the treatment regimen. Although there is evidence for an effect of 5,10-methylenetetrahydrofolate reductase gene (MTHFR) C677T and A1298C variations on drug response in ALL, its risk association for ALL is still unresolved. In a case-control study of 203 patients with ALL and 246 controls and meta-analysis in the Indian population, we showed an insignificant association of MTHFR C677T and A1298C genotypes with childhood and adult ALL. Comprehensive in silico characterization of non-synonymous single nucleotide polymorphisms (nsSNPs) and SNPs of the 3' untranslated region (UTR) revealed nine nsSNPs as deleterious, and three SNPs in the 3'UTR could possibly alter the binding of miRNAs. The study revealed that several overlooked SNPs may contribute to the risk of ALL susceptibility and further studies of these SNPs with functional characterization in a large sample size are required to understand the significant role of MTHFR in ALL development. PMID:25115513

  17. Association between MTHFR A1298C polymorphism and hepatocellular carcinoma risk

    PubMed Central

    Zhang, Haiyan; Li, Guang; Zhang, Zhen

    2015-01-01

    Background: Hepatocarcinogenesis is a complex process that is influenced by many factors. Several studies have investigated the relationship between MTHFR A1298C polymorphism and hepatocellular carcinoma (HCC) risk, but the results are inconsistent. Therefore, we performed a meta-analysis covering a large sample size to address this controversy. Methods: Eligible studies were searched using PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI) databases. A total of 7 studies from 6 publications with 2035 cases and 3096 controls were included. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) was calculated by the fixed or random effects to evaluate the correlation between MTHFR A1298C polymorphism and HCC risk. The Q statistic and I2 statistic were used to assess the statistical heterogeneity among studies. Publication bias was evaluated by Egger’s linear regression test and Begg’s funnel plot. Results: In present study, the results showed that MTHFR A1298C polymorphism was not significantly associated with risk of HCC based on CC + AC vs. AA genetic model (OR=1.01, 95% CI=0.90-1.13). Similarly, in the subgroup analysis by ethnicity, no significant HCC risk was found in Asian population (OR=1.02, 95% CI=0.91-1.14). In the subgroup analysis based on source of control, we found that MTHFR A1298C polymorphism showed no effects on the occurrence of HCC in the population-based (PB) and hospital-based (HB) group (OR=0.97, 95% CI=0.83-1.15; OR=1.04, 95% CI=0.89-1.21). Conclusion: This meta-analysis suggested that MTHFR A1298C polymorphism may not be a risk factor for HCC. PMID:26309569

  18. Maternal Methylenetetrahydrofolate Reductase C677T Polymorphism and Down Syndrome Risk: A Meta-Analysis from 34 Studies

    PubMed Central

    Rai, Vandana; Yadav, Upendra; Kumar, Pradeep; Yadav, Sushil Kumar; Mishra, Om Prakesh

    2014-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of folate metabolic pathway which catalyzes the irreversible conversion of 5, 10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. 5-methyltetrahydrofolate donates methyl group for the methylation of homocysteine to methionine. Several studies have investigated maternal MTHFR C677T polymorphism as a risk factor for DS, but the results were controversial and inconclusive. To come into a conclusive estimate, authors performed a meta-analysis. Aim A meta-analysis of published case control studies was performed to investigate the association between maternal MTHFR C677T polymorphism and Down syndrome. Methods PubMed, Google Scholar, Elsevier, Springer Link databases were searched to select the eligible case control studies using appropriate keywords. The pooled odds ratio (OR) with 95%confidence interval were calculated for risk assessment. Results Thirty four studies with 3,098 DS case mothers and 4,852 control mothers were included in the present meta-analysis. The pooled OR was estimated under five genetic models and significant association was found between maternal MTHFR 677C>T polymorphism and Down syndrome under four genetic models except recessive model (for T vs. C, OR = 1.26, 95% CI = 1.09–1.46, p = 0.001; for TT vs. CC, OR = 1.49, 95% CI = 1.13–1.97, p = 0.008; for CT vs. CC, OR = 1.29, 95% CI = 1.10–1.51, p = 0.001; for TT+CT vs. CC, OR = 1.35, 95% CI = 1.13–1.60, p = 0.0008; for TT vs. CT+CC, OR = 0.76, 95% CI = 0.60–0.94, p = 0.01). Conclusion The results of the present meta-analysis support that maternal MTHFR C677T polymorphism is a risk factor for DS- affected pregnancy. PMID:25265565

  19. Uracil misincorporation into DNA of leukocytes of young women with positive folate balance depends on plasma vitamin B12 concentrations and methylenetetrahydrofolate reductase polymorphisms. A pilot study.

    PubMed

    Kapiszewska, Maria; Kalemba, Malgorzata; Wojciech, Urszula; Milewicz, Tomasz

    2005-08-01

    Changes in the folate and vitamin B12 status in the body influence the extent of uracil misincorporation (UrMis) into DNA, which is one of the biomarkers of genomic stability and, thus, portends a risk of cancer. In our study, the level of UrMis into DNA was evaluated by the comet assay (using the specific DNA repair enzyme, uracil DNA glycosylase) in leukocytes from blood donated by healthy young women with positive folate balance achieved by 4 weeks of folic acid supplementation (400 microg/day). The nutritional status was evaluated on the basis of nine food diaries recorded by the subjects during two winter months. The data were computerized, and the intake of nutrients and micronutrients was estimated using the DIETA 2 program (Food and Nutrition Institute, Warsaw, Poland) linked to recently updated Polish food tables. The plasma folate and vitamin B12 concentration, as well as methylenetetrahydrofolate reductase (MTHFR) polymorphisms, were evaluated to determine their influence on the level of UrMis into DNA. The mean value of B12 intake for all subjects reached 100% of the Polish recommended dietary allowances (RDA), whereas the mean value of folate intake, before folate supplementation, was 50%, suggesting moderate deficiency. Folic acid supplementation brought the folate intake way above the RDA, and plasma folate concentration in each individual was above the deficient range (mean value 14.67 ng/ml). The UrMis did not correlate with the plasma folate concentration, but the level of UrMis was significantly lower in subjects with plasma vitamin B12 concentration above 400 pg/ml (P=.02) only after folic acid supplementation. The concentration of folate in plasma correlated (PMTHFR homozygote 1298 AA but not with the MTHFR 677 genotype. When subjects were grouped according to genotype, the mean concentration of folate in plasma was significantly lower in subjects with the MTHFR 677 (CT+TT) polymorphism, which was accompanied by a

  20. MTHFR (677 and 1298) and IL-6-174 G/C genes in pathogenesis of Alzheimer's and vascular dementia and their epistatic interaction.

    PubMed

    Mansoori, Nasim; Tripathi, Manjari; Luthra, Kalpana; Alam, Rizwan; Lakshmy, Ramakrishnan; Sharma, Subhadra; Arulselvi, Subramanyam; Parveen, Shama; Mukhopadhyay, Asok K

    2012-05-01

    Genetic risk factors play an important role in the pathogenesis of Alzheimer disease (AD) and vascular dementia (VaD). In this case-control study, we examined C677T and A1298C (rs1801133 and rs1801131) polymorphism in the methylenetetrahydrofolate reductase (MTHFR) genes and their correlation with plasma levels of homocysteine (Hcy) in AD and VaD cases and evaluated the gene-gene interaction (epistasis) with IL-6-174 G/C (rs1800795). CC genotype was associated with elevated levels of plasma homocysteine (p = 0.004) as compared with genotype AA of rs1801131. In AD, we observed a significant (p = 0.04) association with C alleles of rs1801131. Regression analysis revealed that the presence of both rs1801133 T and rs1800795 C alleles increased the odds of developing AD by 2.5 and VaD by 3.7-fold. While rs1800795 (CC or GC) genotypes alone increased the odds of developing VaD by 2.2-fold, the presence of CC genotype of rs1801131 nullified this effect. The findings support the hypothesis that multiple genes are involved to alter the odds of developing AD and VaD. PMID:22015309

  1. Methylenetetrahydrofolate reductase variants associated with hypertension and cardiovascular disease interact with dietary polyunsaturated fatty acids to modulate plasma homocysteine in puerto rican adults.

    PubMed

    Huang, Tao; Tucker, Katherine L; Lee, Yu-Chi; Crott, Jimmy W; Parnell, Laurence D; Shen, Jian; Smith, Caren E; Ordovas, Jose M; Li, Duo; Lai, Chao-Qiang

    2011-04-01

    Although methylenetetrahydrofolate reductase (MTHFR) genetic variants are associated with plasma homocysteine (Hcy) and cardiovascular disease (CVD), little is known whether dietary fatty acid intake modulates these associations. The goal was to examine the interaction of MTHFR variants with dietary fatty acids influencing plasma Hcy in 995 Boston Puerto Rican adults. We found that plasma Hcy concentration was negatively correlated with (n-3) PUFA intake (r = -0.117; P = 0.022), and the ratio of (n-3):(n-6) PUFA in the diet (r = -0.122; P = 0.009). Further, 2 functional MTHFR variants, 1298A>C and 677C>T, which are not in linkage disequilibrium in this population, were significantly associated with hypertension (OR = 1.72, P = 0.024, and OR = 1.60, P = 0.002, respectively). In addition, the 1298A>C variant was significantly associated with CVD (OR = 3.32; P = 0.030). Importantly, this variant exhibited significant interactions with intakes of total and (n-6) PUFA and the (n-3):(n-6) PUFA ratio of the diet. The plasma Hcy concentration of carriers of risk allele 1298C was greater than that of noncarriers only when participants had consumed a high-PUFA diet (>7.8% energy) but was not greater when they had low intake of PUFA (≤7.8% energy). In addition, participants with combined genotypes of both SNP (677 TT with 1298 AC or CC) who consumed high levels of (n-3) PUFA (>0.66% energy) had lower plasma Hcy compared with those who had the same genotype and consumed low levels of (n-3) PUFA (≤0.66% energy). Our study suggests that dietary PUFA intake modulates the effect of 2 MTHFR variants on plasma Hcy in Boston Puerto Rican adults. PMID:21270364

  2. Human brain aldehyde reductases: relationship to succinic semialdehyde reductase and aldose reductase.

    PubMed

    Hoffman, P L; Wermuth, B; von Wartburg, J P

    1980-08-01

    Human brain contains multiple forms of aldehyde-reducing enzymes. One major form (AR3), as previously shown, has properties that indicate its identity with NADPH-dependent aldehyde reductase isolated from brain and other organs of various species; i.e., low molecular weight, use of NADPH as the preferred cofactor, and sensitivity to inhibition by barbiturates. A second form of aldehyde reductase ("SSA reductase") specifically reduces succinic semialdehyde (SSA) to produce gamma-hydroxybutyrate. This enzyme form has a higher molecular weight than AR3, and uses NADH as well as NADPH as cofactor. SSA reductase was not inhibited by pyrazole, oxalate, or barbiturates, and the only effective inhibitor found was the flavonoid quercetine. Although AR3 can also reduce SSA, the relative specificity of SSA reductase may enhance its in vivo role. A third form of human brain aldehyde reductase, AR2, appears to be comparable to aldose reductases characterized in several species, on the basis of its activity pattern with various sugar aldehydes and its response to characteristic inhibitors and activators, as well as kinetic parameters. This enzyme is also the most active in reducing the aldehyde derivatives of biogenic amines. These studies suggest that the various forms of human brain aldehyde reductases may have specific physiological functions. PMID:6778961

  3. Nitrate and periplasmic nitrate reductases

    PubMed Central

    Sparacino-Watkins, Courtney; Stolz, John F.; Basu, Partha

    2014-01-01

    The nitrate anion is a simple, abundant and relatively stable species, yet plays a significant role in global cycling of nitrogen, global climate change, and human health. Although it has been known for quite some time that nitrate is an important species environmentally, recent studies have identified potential medical applications. In this respect the nitrate anion remains an enigmatic species that promises to offer exciting science in years to come. Many bacteria readily reduce nitrate to nitrite via nitrate reductases. Classified into three distinct types – periplasmic nitrate reductase (Nap), respiratory nitrate reductase (Nar) and assimilatory nitrate reductase (Nas), they are defined by their cellular location, operon organization and active site structure. Of these, Nap proteins are the focus of this review. Despite similarities in the catalytic and spectroscopic properties Nap from different Proteobacteria are phylogenetically distinct. This review has two major sections: in the first section, nitrate in the nitrogen cycle and human health, taxonomy of nitrate reductases, assimilatory and dissimilatory nitrate reduction, cellular locations of nitrate reductases, structural and redox chemistry are discussed. The second section focuses on the features of periplasmic nitrate reductase where the catalytic subunit of the Nap and its kinetic properties, auxiliary Nap proteins, operon structure and phylogenetic relationships are discussed. PMID:24141308

  4. Effect of MTHFR, TGFβ1, and TNFB polymorphisms on osteoporosis in rheumatoid arthritis patients.

    PubMed

    Saad, Mohamed N; Mabrouk, Mai S; Eldeib, Ayman M; Shaker, Olfat G

    2015-09-01

    Diseases of the immune and the skeletal systems should be studied together for the deep interaction between them. Many studies consider osteoporosis (OP) as a risk factor for the prediction of disease progression in rheumatoid arthritis (RA). The aim of this research is to study the effect of four single nucleotide polymorphisms (SNPs) on RA patients with and without OP. The examined SNPs (MTHFR (C677T, and A1298C), TGFβ1 (T869C), and TNFB (A252G)) were tested by genotyping 17 RA patients with OP and 72 RA patients without OP. Associations were tested using four models (multiplicative, dominant, recessive, and co-dominant). The studied SNPs were not significantly associated with the risk of OP in RA. MTHFR, TGFβ1, and TNFB polymorphisms don't appear to be clinically useful genetic markers for predicting RA severity in Egyptian women population. PMID:25981594

  5. MTHFR C677T polymorphism interaction with heavy alcohol consumption increases head and neck carcinoma risk.

    PubMed

    Zhuo, Xianlu; Song, Jue; Li, Dairong; Wu, Yongzhong; Zhou, Qi

    2015-01-01

    MTHFR C677T polymorphism has been indicated to be a risk factor for cancers, but its association with head and neck cancer (HNC) risk remains inconclusive. In the present study, we aimed to get a more precise estimation by performing a quantitative meta-analysis. Published papers up to Jun 2014 was searched and screened. Necessary information was rigorously extracted for data pooling and analyzing, and then, subgroup analyses on ethnicity, source of controls, sample size, tumor type, smoking and drinking status were also carried out. As a result, twenty-three case-control studies including 14298 subjects were included. The overall data failed to reveal a significant association between MTHFR C677T polymorphism and HNC risk (homozygote comparison model: OR = 1.16; 95%CI = 0.93-1.45; dominant model: OR = 1.05; 95%CI =  .90-1.21; recessive model: OR = 1.14; 95%CI = 0.93-1.38). However, in the subgroup analysis about drinking status, increase risk was shown in the heavy drinking subgroup (TT vs CC: OR = 3.11; 95%CI = 1.52-3.02). In conclusion, the results of the present study suggest that Homozygous TT alleles of MTHFR C677T polymorphism might be a risk factor for HNC among individuals who have a heavy drinking history. Further studies are needed to get a more definitive conclusion. PMID:26035704

  6. MTHFR C677T polymorphism interaction with heavy alcohol consumption increases head and neck carcinoma risk

    PubMed Central

    Zhuo, Xianlu; Song, Jue; Li, Dairong; Wu, Yongzhong; Zhou, Qi

    2015-01-01

    MTHFR C677T polymorphism has been indicated to be a risk factor for cancers, but its association with head and neck cancer (HNC) risk remains inconclusive. In the present study, we aimed to get a more precise estimation by performing a quantitative meta-analysis. Published papers up to Jun 2014 was searched and screened. Necessary information was rigorously extracted for data pooling and analyzing, and then, subgroup analyses on ethnicity, source of controls, sample size, tumor type, smoking and drinking status were also carried out. As a result, twenty-three case-control studies including 14298 subjects were included. The overall data failed to reveal a significant association between MTHFR C677T polymorphism and HNC risk (homozygote comparison model: OR = 1.16; 95%CI = 0.93-1.45; dominant model: OR = 1.05; 95%CI = 0.90-1.21; recessive model: OR = 1.14; 95%CI = 0.93-1.38). However, in the subgroup analysis about drinking status, increase risk was shown in the heavy drinking subgroup (TT vs CC: OR = 3.11; 95%CI = 1.52-3.02). In conclusion, the results of the present study suggest that Homozygous TT alleles of MTHFR C677T polymorphism might be a risk factor for HNC among individuals who have a heavy drinking history. Further studies are needed to get a more definitive conclusion. PMID:26035704

  7. MTHFR A1298C polymorphism and ovarian cancer risk: a meta-analysis.

    PubMed

    Shi, X Y; Shen, Q

    2015-01-01

    Numerous studies have evaluated the association between the MTHFR A1298C polymorphism and ovarian cancer risk. However, the specific association is still controversial. Therefore, we performed the present meta-analysis. A systematic literature search of PubMed and Embase databases was undertaken in August 2014, and the reference lists of articles were retrieved. ORs with their 95%CI were calculated to evaluate the strength of the association. Meta-analysis was performed using the STATA version 12.0 software package and publication bias was investigated by Begg's funnel plot. Five case-control studies from three publications (with 7026 subjects) on the relationship between the MTHFR A1298C polymorphism and ovarian cancer were analyzed by meta-analysis. Overall, no significant variation in ovarian cancer risk was detected in any of the genetic models (AA vs CC: OR = 0.93, 95%CI = 0.78-1.10; AA vs AC: OR = 1.02, 95%CI = 0.92-1.13; dominant model: OR = 1.00, 95%CI = 0.91-1.10; recessive model: OR = 0.92, 95%CI = 0.78-1.08). In conclusion, this meta-analysis suggests that the A1298C polymorphism in the MTHFR gene may be not associated with susceptibility to ovarian cancer. PMID:26345746

  8. [Association between mthfr gene polymorphisms and toxicity of HDMTX chemotherapy in acute lymphocytic leukemia].

    PubMed

    Liu, Jing-Xia; Chen, Jie-Ping; Tan, Wen; Lin, Dong-Xin

    2008-06-01

    This study was aimed to investigate the association between mthfr gene polymorphisms and toxicity of HDMTX in acute lymphocytic leukemia patients. A total of 44 patients were selected, and DNA was extracted from their peripheral blood. PCR-RFLP was used to determine the genotypes of mthfr. The toxicity response of patients received HDMTX chemotherapy was observed. The results showed that the toxicity of HDMTX to carriers of the variant allele at codon 677 (CT or TT) increased, as compared with individuals with the common CC genotype (OR = 3.75, 95% CI 1 - 14, p = 0.04). In contrast, the toxicity of HDMTX to ALL patients with the variant allele at codon 1298 (AC or CC) decreased as compared with the common AA genotype carriers (OR = 0.12, 95% CI: 0.026 - 0.564, p = 0.007). As compared with carriers of the variant allele at coden 1298 (AC or CC), the toxicity of HDMTX to patients with TT genotype at 677 and AA genotype at 1298 increased (OR = 16.5, 95% CI: 0.026 - 0.564). It is concluded that mthfr gene polymorphisms associate with the toxicity of HDMTX chemotherapy in acute lymphocytic leukemia. PMID:18549614

  9. Associations of MTHFR Gene Polymorphisms with Hypertension and Hypertension in Pregnancy: A Meta-Analysis from 114 Studies with 15411 Cases and 21970 Controls

    PubMed Central

    Yang, Boyi; Fan, Shujun; Zhi, Xueyuan; Li, Yongfang; Liu, Yuyan; Wang, Da; He, Miao; Hou, Yongyong; Zheng, Quanmei; Sun, Guifan

    2014-01-01

    Background Several epidemiological studies have investigated the associations of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms with hypertension (H) or hypertension in pregnancy (HIP). However, the results were controversial. We therefore performed a comprehensive meta-analysis to provide empirical evidences on the associations. Methodologies The English and Chinese databases were systematically searched to identify relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the associations. Meta-regression, subgroup analysis, sensitivity analysis, cumulative meta-analysis and assessment of publication bias were performed in our study. Principal Findings A total of 114 studies with 15411 cases and 21970 controls were included, 111 studies with 15094 cases and 21633 controls for the C677T polymorphism and 21 with 2533 cases and 2976 controls for the A1298C polymorphism. Overall, the C677T polymorphism was significantly associated with H and HIP (H & HIP: OR = 1.26, 95% CI = 1.17–1.34; H: OR = 1.36, 95% CI = 1.20–1.53; HIP: OR = 1.21, 95% CI = 1.08–1.32). Stratified analysis by ethnicity revealed a significant association among East Asians and Caucasians, but not among Latinos, Black Africans, and Indians and Sri Lankans. In the stratified analyses according to source of controls, genotyping method, sample size and study quality, significant associations were observed in all the subgroups, with the exception of population based subgroup in H studies and large sample size and “others” genotyping method subgroups in HIP studies. For the A1298C polymorphism, no significant association was observed either in overall or subgroup analysis under all genetic models. Conclusions This meta-analysis suggests that the MTHFR C677T rather than A1298C polymorphism may be associated with H & HIP, especially among East Asians and Caucasians. PMID:24505291

  10. Methylenetetrahydrofolate reductase gene A1298C polymorphism in pediatric stroke--case-control and family-based study.

    PubMed

    Balcerzyk, Anna; Niemiec, Paweł; Kopyta, Ilona; Emich-Widera, Ewa; Pilarska, Ewa; Pienczk-Ręcławowicz, Karolina; Kaciński, Marek; Wendorff, Janusz; Żak, Iwona

    2015-01-01

    Moderate hyperhomocysteinemia is one of the risk factors of pediatric stroke. Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme, which regulates homocysteine metabolism, and some polymorphisms of gene encoding this enzyme are associated with a decreased activity of the enzyme. The aim of the study was to assess an association between the A1298C polymorphism and pediatric stroke. We also evaluated a possible synergistic effect of A1298C and C677T polymorphisms of this gene. The study group consisted of 88 children after ischemic stroke, 142 of their parents and 111 controls. The A1298C polymorphism was genotyped using the restriction fragment length polymorphism method. We used 2 study designs: a case-control model and a family-based association test. The Statistica 7.1 and EpiInfo 6 softwares were used in all analyses. We did not observe any statistically significant differences either in the transmission of the A allele in the family-based test or in the frequency of the A allele in the patients group compared with the controls. We also did not notice any significant additive or synergistic effects between the A1298C and C677T polymorphisms. An analysis of the results obtained in this study and a critical review of previously published studies indicate that the A1298C polymorphism of the MTHFR gene is not related to ischemic stroke in children. PMID:25440348

  11. Effect of folate status and methylenetetrahydrofolate reductase genotypes on the complications and outcome of high dose methotrexate chemotherapy in north Indian children with acute lymphoblastic leukemia

    PubMed Central

    Moulik, Nirmalya Roy; Kumar, Archana; Agrawal, Suraksha; Mahdi, Abbas Ali; Kumar, Ashutosh

    2016-01-01

    Purpose: The genes of the folate metabolic pathway have been associated with toxicities during high dose methotrexate therapy for childhood ALL, however, the importance of intrinsic folate status in this regard is unclear. Methods: In the present study the effect of precourse folate levels and MTHFR genotypes on the complications during high dose methotrexate chemotherapy in children with ALL were examined. Results: Twenty-one children were studied. Folate deficiency was associated with higher incidence of neutropenia (P = 0.03) and longer duration of chemotherapy interruption (P = 0.009). Children with MTHFR1298 mutations needed more red cell transfusion (P = 0.03). All 3 deaths encountered were seen in folate deficient children. Conclusions: Folate deficiency was associated with higher complications during high dose methotrexate therapy, the implications of which are important especially in resource poor settings with high prevalence of folate deficiency. PMID:27168705

  12. Characterization of mitochondrial thioredoxin reductase from C. elegans

    SciTech Connect

    Lacey, Brian M.; Hondal, Robert J. . E-mail: Robert.Hondal@uvm.edu

    2006-08-04

    Thioredoxin reductase catalyzes the NADPH-dependent reduction of the catalytic disulfide bond of thioredoxin. In mammals and other higher eukaryotes, thioredoxin reductases contain the rare amino acid selenocysteine at the active site. The mitochondrial enzyme from Caenorhabditis elegans, however, contains a cysteine residue in place of selenocysteine. The mitochondrial C. elegans thioredoxin reductase was cloned from an expressed sequence tag and then produced in Escherichia coli as an intein-fusion protein. The purified recombinant enzyme has a k {sub cat} of 610 min{sup -1} and a K {sub m} of 610 {mu}M using E. coli thioredoxin as substrate. The reported k {sub cat} is 25% of the k {sub cat} of the mammalian enzyme and is 43-fold higher than a cysteine mutant of mammalian thioredoxin reductase. The enzyme would reduce selenocysteine, but not hydrogen peroxide or insulin. The flanking glycine residues of the GCCG motif were mutated to serine. The mutants improved substrate binding, but decreased the catalytic rate.

  13. Role of plasma homocysteine levels and MTHFR polymorphisms on IQ scores in children and young adults with epilepsy treated with antiepileptic drugs.

    PubMed

    Di Rosa, Gabriella; Lenzo, Patrizia; Parisi, Eleonora; Neri, Milena; Guerrera, Silvia; Nicotera, Antonio; Alibrandi, Angela; Germanò, Eva; Caccamo, Daniela; Spanò, Maria; Tortorella, Gaetano

    2013-12-01

    Homocysteine (Hcy) is a sulfur-containing amino acid involved in methionine metabolism. High plasma total Hcy (tHcy) has been quite frequently reported in patients with epilepsy treated with antiepileptic drugs (AEDs) mainly related to plasma folate reduction induced by AEDs themselves. The role of C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase gene (MTHFR) on the increase of plasma tHcy in patients with epilepsy taking AEDs is still controversial. Cognitive impairment may be associated with epilepsy either as the result of the epileptic syndrome per se or as a side effect induced by the AEDs. High plasma tHcy levels were associated with lower cognitive performances in patients affected by Alzheimer's disease and mild cognitive impairment and in healthy elderly. We searched for a correlation between plasma tHcy levels with the intelligence quotient (IQ) scores in a population of children and young adults with epilepsy treated with old and/or newer AEDs. The study group encompassed 179 patients (92 M, 51.5%) followed at our Unit of Child Neuropsychiatry and aged between 4 and 25years (mean+SD: 14.03±4.25). The inclusion criteria included the following: 1) diagnosis of epilepsy of "unknown cause" (cryptogenic) according to the ILAE classification, 2) age older than 3years, 3) stabilized antiepileptic treatment for at least 6months, and 4) clinical records of cognitive tests, plasma tHcy value, and results of MTHFR polymorphisms. Patients' mean tHcy value was 9.71±3.13μM/L (tHcy<9μM/L as our laboratory cutoff in nonepileptic controls). The mean TIQ score was 85.22 (SD±24.12); the mean VIQ score was 86.32 (SD±20.86); and the mean PIQ score was 86.94 (SD±21.51). C677T and A1298C MTHFR polymorphisms were detected in 74/92 (80%) examined patients and distributed into the following: CT (22.3%), TT (14.9%), CC (10.3%) for C677T, AC (16%), CC (1.1%), and AA (30.3%) for A1298C. Plasma tHcy levels were not significantly related to the IQ scores

  14. Methylenetetrahydrofolate Reductase C677T Polymorphism and Recurrent Pregnancy Loss Risk in Asian Population: A Meta-analysis.

    PubMed

    Rai, Vandana

    2016-10-01

    The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene was implicated to be associated with thrombophilia due to its role in catalyzing the formation of 5-methylenetetrahydrofolate, a co-substrate for the conversion of homocysteine to methionine. Several case-control studies were investigated MTHFR C677T polymorphism as risk for recurrent pregnancy loss (RPL). These studies rendered contradictory results, some indicating that the polymorphism is associated with the risk of RPL whereas others concluded there is no association. To shed light on these inconclusive findings, a meta-analysis of all available studies published from Asian population relating the C677T polymorphism to the risk of RPL was conducted. The following electronic databases were searched without language restrictions: PubMed, Google Scholars, Elsevier and Springer Link up to December, 2015. Meta-analysis was performed using MetaAnalyst and Mix version 1.7. Meta-analysis results suggested that MTHFR C677T polymorphism contributed to the increased RPL risk in Asian population using all five genetic models (for T vs. C: OR 1.35, 95 % CI 1.09-1.68, p = 0.009; for TT + CT vs. CC: OR 1.44, 95 % CI 1.14-1.82, p = 0.006; for CT vs. CC: OR 1.39, 95 % CI 1.07-1.8, p = 0.01; for TT vs. CC: OR 1.79, 95 % CI 1.23.2.6, p = 0.007; for TT vs. CT + CC: OR 1.61, 95 % CI 1.02-2.56, p = 0.04). In conclusion, this meta-analysis demonstrates a strong association between the MTHFR C677T variant and RPL in Asian population and raising the importance of the use of folate in its treatment and prevention. PMID:27605737

  15. Evaluation of Factor V G1691A, prothrombin G20210A, Factor XIII V34L, MTHFR A1298C, MTHFR C677T and PAI-1 4G/5G genotype frequencies of patients subjected to cardiovascular disease (CVD) panel in south-east region of Turkey.

    PubMed

    Oztuzcu, Serdar; Ergun, Sercan; Ulaşlı, Mustafa; Nacarkahya, Gülper; Iğci, Yusuf Ziya; Iğci, Mehri; Bayraktar, Recep; Tamer, Ali; Çakmak, Ecir Ali; Arslan, Ahmet

    2014-06-01

    Cardiovascular disease (CVD) risk factors, such as arterial hypertension, obesity, dyslipidemia or diabetes mellitus, as well as CVDs, including myocardial infarction, coronary artery disease or stroke, are the most prevalent diseases and account for the major causes of death worldwide. In the present study, 4,709 unrelated patients subjected to CVD panel in south-east part of Turkey between the years 2010 and 2013 were enrolled and DNA was isolated from the blood samples of these patients. Mutation analyses were conducted using the real-time polymerase chain reaction method to screen six common mutations (Factor V G1691A, PT G20210A, Factor XIII V34L, MTHFR A1298C and C677T and PAI-1 -675 4G/5G) found in CVD panel. The prevalence of these mutations were 0.57, 0.25, 2.61, 13.78, 9.34 and 24.27 % in homozygous form, respectively. Similarly, the mutation percent of them in heterozygous form were 7.43, 3.44, 24.91, 44.94, 41.09 and 45.66%, respectively. No mutation was detected in 92 (1.95%) patients in total. Because of the fact that this is the first study to screen six common mutations in CVD panel in south-east region of Turkey, it has a considerable value on the diagnosis and treatment of these diseases. Upon the results of the present and previous studied a careful examination for these genetic variants should be carried out in thrombophilia screening programs, particularly in Turkish population. PMID:24532105

  16. Isolated menthone reductase and nucleic acid molecules encoding same

    DOEpatents

    Croteau, Rodney B; Davis, Edward M; Ringer, Kerry L

    2013-04-23

    The present invention provides isolated menthone reductase proteins, isolated nucleic acid molecules encoding menthone reductase proteins, methods for expressing and isolating menthone reductase proteins, and transgenic plants expressing elevated levels of menthone reductase protein.

  17. Association of methylenetetrahydrofolate reductase C677T polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

    PubMed Central

    2010-01-01

    Background The association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and serum lipid profiles is still controversial in diverse ethnics. Bai Ku Yao is an isolated subgroup of the Yao minority in China. The aim of the present study was to eveluate the association of MTHFR C677T polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations. Methods A total of 780 subjects of Bai Ku Yao and 686 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the MTHFR C677T was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. Results The levels of serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.05-0.001). The frequency of C and T alleles was 77.4% and 22.6% in Bai Ku Yao, and 60.9% and 39.1% in Han (P < 0.001); respectively. The frequency of CC, CT and TT genotypes was 58.7%, 37.3% and 4.0% in Bai Ku Yao, and 32.6%, 56.4% and 11.0% in Han (P < 0.001); respectively. The levels of TC and LDL-C in both ethnic groups were significant differences among the three genotypes (P < 0.05-0.01). The T allele carriers had higher serum TC and LDL-C levels than the T allele noncarriers. The levels of ApoB in Han were significant differences among the three genotypes (P < 0.05). The T allele carriers had higher serum ApoB levels as compared with the T allele noncarriers. The levels of TC, TG and LDL-C in Bai Ku Yao were correlated with genotypes (P < 0.05-0.001), whereas the levels of LDL-C in Han were associated with genotypes (P < 0.001). Serum lipid parameters were also correlated with sex, age, body mass index, alcohol consumption, cigarette smoking, and blood pressure in the both ethnic

  18. Methylenetetrahydrofolate reductase gene C677T polymorphism and breast cancer risk: Evidence for genetic susceptibility

    PubMed Central

    Kumar, Pradeep; Yadav, Upendra; Rai, Vandana

    2015-01-01

    There are several evidences supporting the role of 5–10 methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms in breast cancer (BC). Case control association studies on breast cancer have been repeatedly performed over the last two decades, but results are inconsistent. We performed a meta-analysis to confirm the association between MTHFR C677T polymorphism and BC risk. The articles were retrieved by searching the PubMed, Google Scholar, and Springer Link databases. Crude odds ratios (OR) with 95% confidence intervals (CIs) was used to assess the strength of association between C677T polymorphism and BC. Publication bias was assessed by Egger's and Begg-Mazumdar tests. Meta-analysis was performed with Open Meta Analyst. Total 75 studies with 31,315 cases and 35, 608 controls were found suitable for the inclusion in the present meta-analysis. The results of meta-analysis suggested that there were moderate significant association between C677T polymorphism and BC risk using overall comparisons in five genetic models (T vs. C: OR = 1.08, 95% CI = 1.03–1.13, p = < 0.001; TT + CT vs. CC: OR = 1.06, 95% CI = 1.02–1.09, p = < 0.001; TT vs. CC: OR = 1.17, 95% CI = 1.06–1.28, p = 0.001; CT vs. CC OR = 1.05, 95% CI = 1.01–1.08, p = 0.005; TT vs. CT + CC: OR = 1.12, 95% CI = 1.03–1.22, p = 0.005). In conclusion, results of present meta-analysis showed modest association between MTHFR C677T polymorphism with breast cancer in total studies. However, sub-group analysis results based on ethnicity showed strong significant association between TT genotype and breast cancer (TT vs. CC; OR°=°1.26; 95% CI: 1.06–1.51; p = 0.009) in Asian population but in Caucasian population such association was not observed (TT vs. CC; OR°=°1.08; 95% CI: 0.99–1.14; p = 0.05). PMID:26629412

  19. Zeatin reductase in Phaseolus embryos

    SciTech Connect

    Martin, R.C.; Mok, David, W.S.; Mok, M.C. )

    1989-04-01

    Zeatin was converted to O-xylosylzeatin in embryos of Phaseolus vulgaris . O-xylosyldihydrozeatin was also identified as a zeatin metabolite. Incubation of embryo extracts with {sup 14}C-zeatin and {sup 14}C-O-xylosylzeatin revealed that reduction preceeds the O-xylosylation of zeatin. An enzyme responsible for reducing the N{sup 6}-side chain was isolated and partially purified using ammonium sulfate fractionation and affinity, gel filtration and anion exchange chromatography. The NADPH dependent reductase was zeatin specific and did not recognize cis-zeatin, ribosylzeatin, i{sup 6}Ade or i{sup 6}Ado. Two forms of the reductase could be separated by either gel filtration or anion exchange HPLC. The HMW isozyme (Mr. 55,000) eluted from the anion exchange column later than the LMW isozyme (Mr. 25,000). Interspecific differences in zeatin reductase activity were also detected.

  20. TPMT and MTHFR Genotype is not Associated With Altered Risk of Thioguanine-Related Sinusoidal Obstruction Syndrome in Pediatric Acute Lymphoblastic Leukemia: A Report from the Children’s Oncology Group

    PubMed Central

    Wray, Lisa; Vujkovic, Marijana; McWilliams, Thomas; Cannon, Shannon; Devidas, Meenakshi; Stork, Linda; Aplenc, Richard

    2014-01-01

    Sinusoidal obstruction syndrome is a complication of therapy for pediatric ALL and may be modified by thiopurine methyltransferase activity as well as by MTHFR genotype. We assessed TPMT * 3A, * 3B, * 3C, and MTHFR C677T and A1298C germline genetic polymorphisms among 351 patients enrolled in the thioguanine treatment arm of CCG-1952 clinical trial. TPMT and MTHFR C677T genotypes were not associated with SOS risk. The combination of MTHFR and TPMT variant genotypes was not associated with SOS risk. These suggest that germline genetic variation in TPMT and MTHFR do not significantly alter SOS risk in patients exposed to thioguanine. PMID:24737678

  1. MTHFR C677T Gene Polymorphism and Head and Neck Cancer Risk: A Meta-Analysis Based on 23 Publications

    PubMed Central

    Niu, Yu-Ming; Deng, Mo-Hong; Chen, Wen; Zeng, Xian-Tao; Luo, Jie

    2015-01-01

    Objective. Conflicting results on the association between MTHFR polymorphism and head and neck cancer (HNC) risk were reported. We therefore performed a meta-analysis to derive a more precise relationship between MTHFR C677T polymorphism and HNC risk. Methods. Three online databases of PubMed, Embase, and CNKI were researched on the associations between MTHFR C677T polymorphism and HNC risk. Twenty-three published case-control studies involving 4,955 cases and 8,805 controls were collected. Odds ratios (ORs) with 95% confidence interval (CI) were used to evaluate the relationship between MTHFR C677T polymorphism and HNC risk. Sensitivity analysis, cumulative analyses, and publication bias were conducted to validate the strength of the results. Results. Overall, no significant association between MTHFR C677T polymorphism and HNC risk was found in this meta-analysis (T versus C: OR = 1.04, 95% CI = 0.92–1.18; TT versus CC: OR = 1.15, 95% CI = 0.90–1.46; CT versus CC: OR = 1.00, 95% CI = 0.85–1.17; CT + TT versus CC: OR = 1.01, 95% CI = 0.87–1.18; TT versus CC + CT: OR = 1.11, 95% CI = 0.98–1.26). In the subgroup analysis by HWE, ethnicity, study design, cancer location, and negative significant associations were detected in almost all genetic models, except for few significant risks that were found in thyroid cancer. Conclusion. This meta-analysis demonstrates that MTHFR C677T polymorphism may not be a risk factor for the developing of HNC. PMID:25802478

  2. Genetic and epigenetic variation in the DNMT3B and MTHFR genes and colorectal adenoma risk.

    PubMed

    Ho, Vikki; Ashbury, Janet E; Taylor, Sherryl; Vanner, Stephen; King, Will D

    2016-05-01

    Polymorphisms in DNMT3B and MTHFR have been implicated in cancer etiology; however, it is increasingly clear that gene-specific DNA methylation also affects gene expression. A cross-sectional study (N = 272) investigated the main and joint effects of polymorphisms and DNA methylation in DNMT3B and MTHFR on colorectal adenoma risk. Polymorphisms examined included DNMT3B c.-6-1045G > T, and MTHFR c.665C > T and c.1286A > C. DNA methylation of 66 and 28 CpG sites in DNMT3B and MTHFR, respectively, was quantified in blood leukocytes using Sequenom EpiTYPER®. DNA methylation was conceptualized using two approaches: (1) average methylation and (2) unsupervised principal component analysis to identify variables that represented methylation around the transcription start site and the gene coding area of both genes. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) associated with the main and joint effects of polymorphisms and DNA methylation. DNA methyltransferase 3B (DNMT3B) TT versus GG/GT genotypes was associated with increased colorectal adenoma risk (OR = 2.12; 95% CI: 1.03-4.34). In addition, increasing DNA methylation in the gene-coding area of DNMT3B was associated with higher risk of colorectal adenomas (OR = 1.34; 95% CI: 1.01-1.79 per SD). In joint effect analyses, synergistic effects were observed among those with both the DNMT3B TT genotype and higher DNMT3B methylation levels compared to those with GT/GG genotypes and lower methylation levels (OR = 4.19; 95% CI: 1.45-12.13 for average methylation; OR = 4.26; 95%CI: 1.31-13.87 for methylation in the transcription start site). This research provides novel evidence that genetic and epigenetic variations contribute to colorectal adenoma risk, precursor to the majority of colorectal cancer (CRC). Environ. Mol. Mutagen. 57:261-268, 2016. © 2016 Wiley Periodicals, Inc. PMID:27062459

  3. Nitrite Reductase Activity in Engineered Azurin Variants.

    PubMed

    Berry, Steven M; Strange, Jacob N; Bladholm, Erika L; Khatiwada, Balabhadra; Hedstrom, Christine G; Sauer, Alexandra M

    2016-05-01

    Nitrite reductase (NiR) activity was examined in a series of dicopper P.a. azurin variants in which a surface binding copper site was added through site-directed mutagenesis. Four variants were synthesized with copper binding motifs inspired by the catalytic type 2 copper binding sites found in the native noncoupled dinuclear copper enzymes nitrite reductase and peptidylglycine α-hydroxylating monooxygenase. The four azurin variants, denoted Az-NiR, Az-NiR3His, Az-PHM, and Az-PHM3His, maintained the azurin electron transfer copper center, with the second designed copper site located over 13 Å away and consisting of mutations Asn10His,Gln14Asp,Asn16His-azurin, Asn10His,Gln14His,Asn16His-azurin, Gln8Met,Gln14His,Asn16His-azurin, and Gln8His,Gln14His,Asn16His-azurin, respectively. UV-visible absorption spectroscopy, EPR spectroscopy, and electrochemistry of the sites demonstrate copper binding as well as interaction with small exogenous ligands. The nitrite reduction activity of the variants was determined, including the catalytic Michaelis-Menten parameters. The variants showed activity (0.34-0.59 min(-1)) that was slower than that of native NiRs but comparable to that of other model systems. There were small variations in activity of the four variants that correlated with the number of histidines in the added copper site. Catalysis was found to be reversible, with nitrite produced from NO. Reactions starting with reduced azurin variants demonstrated that electrons from both copper centers were used to reduce nitrite, although steady-state catalysis required the T2 copper center and did not require the T1 center. Finally, experiments separating rates of enzyme reduction from rates of reoxidation by nitrite demonstrated that the reaction with nitrite was rate limiting during catalysis. PMID:27055058

  4. Quantification of key red blood cell folates from subjects with defined MTHFR 677C>T genotypes using stable isotope dilution liquid chromatography/mass spectrometry

    PubMed Central

    Huang, Yuehua; Khartulyari, Stefanie; Morales, Megan E.; Stanislawska-Sachadyn, Anna; Von Feldt, Joan M.; Whitehead, Alexander S.; Blair, Ian A.

    2014-01-01

    Red blood cell (RBC) folate levels are established at the time of erythropoiesis and therefore provide a surrogate biomarker for the average folate status of an individual over the preceding four months. Folates are present as folylpolyglutamates, highly polar molecules that cannot be secreted from the RBCs, and must be converted into their monoglutamate forms prior to analysis. This was accomplished using an individual’s plasma pteroylpolyglutamate hydrolase by lysing the RBCs in whole blood at pH 5 in the presence of ascorbic acid. Quantitative conversion of formylated tetrahydrofolate derivatives into the stable 5,10-methenyltetrahydrofolate (5,10-MTHF) form was conducted at pH 1.5 in the presence of [13C5]-5-formyltetrahydrofolate. The resulting [13C5]-5,10-MTHF was then used as an internal standard for the formylated forms of tetrahydrofolate that had been converted into 5,10-MTHF as well any 5,10-MTHF that had been present in the original sample. A stable isotope dilution liquid chromatography-multiple reaction monitoring/mass spectrometry method was validated and then used for the accurate and precise quantification of RBC folic acid, 5-methyltetrahydrofolate (5-MTHF), tetrahydrofolate (THF), and 5,10-MTHF. The method was sensitive and robust and was used to assess the relationship between different methylenetetrahydrofolate reductase (MTHFR) 677C>T genotypes and RBC folate phenotypes. Four distinct RBC folate phenotypes could be identified. These were classified according to the relative amounts of individual RBC folates as type I (5-MTHF >95%; THF <5%; 5,10-MTHF <5%), type II (5-MTHF <95%; THF 5% to 20%; 5,10-MTHF <5%), type III (5-MTHF >55%; THF >20%; 5,10-MTHF >5%), and type IV (5-MTHF <55%; THF >20%; 5,10-MTHF >5%). PMID:18634122

  5. Methotrexate consolidation treatment according to pharmacogenetics of MTHFR ameliorates event-free survival in childhood acute lymphoblastic leukaemia.

    PubMed

    Salazar, J; Altés, A; del Río, E; Estella, J; Rives, S; Tasso, M; Navajas, A; Molina, J; Villa, M; Vivanco, J L; Torrent, M; Baiget, M; Badell, I

    2012-10-01

    Recent advances in treatment for childhood acute lymphoblastic leukaemia (ALL) have significantly increased outcome. High-dose methotrexate (MTX) is the most commonly used regimen during the consolidation period, but the optimal dose remains to be defined. We investigated the usefulness of the MTHFR genotype to increase the MTX dosage in the consolidation phase in 141 childhood ALL patients enrolled in the ALL/SHOP-2005 protocol. We also investigated the pharmacogenetic role of polymorphisms in genes involved in MTX metabolism on therapy-related toxicity and survival. Patients with a favourable MTHFR genotype (normal enzymatic activity) treated with MTX doses of 5 g m⁻² had a significantly lower risk of suffering an event than patients with an unfavourable MTHFR genotype (reduced enzymatic activity) that were treated with the classical MTX dose of 3 g m⁻² (P=0.012). Our results indicate that analysis of the MTHFR genotype is a useful tool to optimise MTX therapy in childhood patients with ALL. PMID:21747412

  6. Meta- and pooled analyses of the methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer risk: a huge-GSEC review.

    PubMed

    Boccia, Stefania; Hung, Rayjean; Ricciardi, Gualtiero; Gianfagna, Francesco; Ebert, Matthias P A; Fang, Jing-Yuan; Gao, Chang-Ming; Götze, Tobias; Graziano, Francesco; Lacasaña-Navarro, Marina; Lin, Dongxin; López-Carrillo, Lizbeth; Qiao, You-Lin; Shen, Hongbing; Stolzenberg-Solomon, Rachael; Takezaki, Toshiro; Weng, Yu-Rong; Zhang, Fang Fang; van Duijn, Cornelia M; Boffetta, Paolo; Taioli, Emanuela

    2008-03-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of folate, whose role in gastric carcinogenesis is controversial. The authors performed a meta-analysis and individual data pooled analysis of case-control studies that examined the association between C677T and A1298C polymorphisms (the former being associated with low folate serum levels) and gastric cancer (meta-analyses: 16 studies, 2,727 cases and 4,640 controls for C677T and seven studies, 1,223 cases and 2,015 controls for A1298C; pooled analyses: nine studies, 1,540 cases and 2,577 controls for C677T and five studies, 1,146 cases and 1,549 controls for A1298C). An increased risk was found for MTHFR 677 TT in the meta-analysis (odds ratio (OR) = 1.52, 95% confidence interval (CI): 1.31, 1.77) and pooled analysis (OR = 1.49, 95% CI: 1.14, 1.95). No association resulted for MTHFR 1298 CC (meta-OR = 0.94, 95% CI: 0.65, 1.35; pooled OR = 0.90, 95% CI: 0.69, 1.34). Results from the pooled analysis of four studies on C677T stratified according to folate levels showed an increased risk for individuals with low (OR = 2.05, 95% CI: 1.13, 3.72) versus high (OR = 0.95, 95% CI: 0.54, 1.67) folate levels. Overall, these findings support the hypothesis that folate plays a role in gastric carcinogenesis. PMID:18162478

  7. The association of gastric cancer risk with plasma folate, cobalamin, and methylenetetrahydrofolate reductase polymorphisms in the European Prospective Investigation into Cancer and Nutrition.

    PubMed

    Vollset, Stein Emil; Igland, Jannicke; Jenab, Mazda; Fredriksen, Ase; Meyer, Klaus; Eussen, Simone; Gjessing, Håkon K; Ueland, Per Magne; Pera, Guillem; Sala, Núria; Agudo, Antonio; Capella, Gabriel; Del Giudice, Giuseppe; Palli, Domenico; Boeing, Heiner; Weikert, Cornelia; Bueno-de-Mesquita, H Bas; Carneiro, Fátima; Pala, Valeria; Vineis, Paolo; Tumino, Rosario; Panico, Salvatore; Berglund, Göran; Manjer, Jonas; Stenling, Roger; Hallmans, Göran; Martínez, Carmen; Dorronsoro, Miren; Barricarte, Aurelio; Navarro, Carmen; Quirós, José R; Allen, Naomi; Key, Timothy J; Bingham, Sheila; Linseisen, Jakob; Kaaks, Rudolf; Overvad, Kim; Tjønneland, Anne; Büchner, Frederike L; Peeters, Petra H M; Numans, Mattijs E; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine; Trichopoulou, Antonia; Lund, Eiliv; Slimani, Nadia; Ferrari, Pietro; Riboli, Elio; González, Carlos A

    2007-11-01

    Previous studies have shown inconsistent associations of folate intake and polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene with gastric cancer risk. Our nested case-control study within the European Prospective Investigation into Cancer and Nutrition cohort is the first prospective study of blood folate levels and gastric cancer. Gastric cancer cases (n=247) and controls (n=631) were matched for study center, age, sex, and time of blood donation. Two common single nucleotide polymorphisms of the MTHFR gene were determined, as were plasma concentrations of folate, cobalamin (vitamin B12), total homocysteine, and methylmalonic acid (cobalamin deficiency marker) in prediagnostic plasma. Risk measures were calculated with conditional logistic regression. Although no relations were observed between plasma folate or total homocysteine concentrations and gastric cancer, we observed a trend toward lower risk of gastric cancer with increasing cobalamin concentrations (odds ratio, 0.79 per SD increase in cobalamin; P=0.01). Further analyses showed that the inverse association between cobalamin and gastric cancer was confined to cancer cases with low pepsinogen A levels (marker of severe chronic atrophic gastritis) at the time of blood sampling. The 677 C-->T MTHFR polymorphism was not associated with gastric cancer, but we observed an increased risk with the variant genotype of the 1298 A-->C polymorphism (odds ratio, 1.47 for CC versus AA; P=0.04). In conclusion, we found no evidence of a role of folate in gastric cancer etiology. However, we observed increased gastric cancer risk at low cobalamin levels that was most likely due to compromised cobalamin status in atrophic gastritis preceding gastric cancer. PMID:18006931

  8. Assessment of tailor-made prevention of atherosclerosis with folic acid supplementation: randomized, double-blind, placebo-controlled trials in each MTHFR C677T genotype.

    PubMed

    Miyaki, Koichi; Murata, Mitsuru; Kikuchi, Haruhito; Takei, Izumi; Nakayama, Takeo; Watanabe, Kiyoaki; Omae, Kazuyuki

    2005-01-01

    This study aimed at assessing the effect of folic acid supplementation quantitatively in each MTHFR C677T genotype and considered the efficiency of tailor-made prevention of atherosclerosis. Study design was genotype-stratified, randomized, double-blind, placebo-controlled trials. The setting was a Japanese company in the chemical industry. Subjects were 203 healthy men after exclusion of those who took folic acid or drugs known to effect folic acid metabolism. Intervention was folic acid 1 mg/day p.o. for 3 months. The primary endpoint was plasma total homocysteine level (tHcy). In all three genotypes, there were significant tHcy decreases. The greatest decrease was in the TT homozygote [6.61 (3.47-9.76) micromol/l] compared with other genotypes [CC: 2.59 (1.81-3.36), CT: 2.64 (2.16-3.13)], and there was a significant trend between the mutated allele number and the decrease. The tHcy were significantly lowered in all the genotypes, but the amount of the decrease differed significantly in each genotype, which was observed at both 1 and 3 months. Using these time-series data, the largest benefit obtained by the TT homozygote was appraised as 2.4 times compared with the CC homozygote. Taking into account the high allele frequency of this SNP, this quantitative assessment should be useful when considering tailor-made prevention of atherosclerosis with folic acid. PMID:15895286

  9. Methylenetetrahydrofolate reductase gene polymorphisms and the risk of anencephaly in Mexico.

    PubMed

    Muñoz, Julia Blanco; Lacasaña, Marina; Cavazos, Ricardo García; Borja-Aburto, Victor Hugo; Galavíz-Hernández, Carlos; Garduño, Clemente Aguilar

    2007-06-01

    The precise etiology of neural tube defects (NTDs) is not known. There is some evidence that mutations in MTHFR gene provide susceptibility to NTDs in some populations; however, other studies have not found this association. One of the problems with previous studies is that they treat NTDs as a homogeneous group, when specific defects could have different etiologies. We conducted a case-control study specifically for anencephaly, based on the Mexican Epidemiological Surveillance System of Neural Tube Defects to evaluate its association with maternal MTHFR 677C > T and 1298A > C polymorphisms, in three states with high frequencies of NTDs: Puebla, Estado de México and Guerrero. We interviewed and collected blood samples from 118 case mothers and 112 control mothers. The questionnaire included information on their reproductive history, socioeconomic characteristics, prenatal care, tobacco and alcohol use, presence of chronic diseases, acute illnesses and fever, consumption of multivitamins and drugs during the periconceptional period. After adjusting for potential confounders, the risk from the mutated homozygous mothers (677TT genotype) was significantly higher than that from mothers with 677CC genotype (OR 3.16, 95% CI 1.29-7.73); in the case of the heterozygous mothers, an increased risk of anencephaly was observed, even though this was not statistically significant (OR 1.81 95% CI 0.78-4.25). The association found between maternal 677TT genotype and anencephaly and the elevated presence of the 677T allele among Mexican women of fertile age urges intensifying folic acid supplementation which has proved to modify this genetic risk in other populations. PMID:17439956

  10. Association between MTHFR C677T polymorphism and depression: a meta-analysis in the Chinese population.

    PubMed

    Jiang, Wei; Xu, Jun; Lu, Xiao-Jie; Sun, Yang

    2016-09-01

    Depression is a worldwide public health issue, and its prevalence increases each year. Although a number of studies have been conducted on the association between MTHFR C677T polymorphism and depression in China, this association remains elusive and controversial. To clarify the impact of MTHFR C677T polymorphism on the risk of depression, a meta-analysis was performed in the Chinese population. Relevant studies were identified using PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure and Chinese Biology Medicine through May 5, 2015. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. A total of 13 case-control studies including 1895 patients and 1913 controls were involved in this meta-analysis. Overall, T variant of MTHFR C677T gene polymorphism was significantly associated with an increased risk of depression in the Chinese population (T vs. C: OR = 1.52, 95% CI = 1.24-1.85; TT + CT vs. CC: OR = 1.64, 95% CI = 1.16-2.30; TT vs. CC: OR = 2.19, 95% CI = 1.49-3.24; TT vs. CC + CT: OR = 1.80, 95% CI = 1.31-2.46). In subgroup analyses stratified by geographic area and source of controls, the significant results were found in population-based studies, in hospital-based studies, in North and South China. The risk conferred by MTHFR C677T polymorphism is higher in North China than in South China. In conclusion, this meta-analysis suggests that MTHFR C677T polymorphism is associated with depression in the Chinese population, but these associations vary in different geographic locations. PMID:26681493

  11. A novel point mutation in a 3{prime} splice site of the NADH-cytochrome b{sub 5} reductase gene results in immunologically undetectable enzyme and impaired NADH-dependent ascorbate regeneration in cultured fibroblasts of a patient with type II hereditary methemoglobinemia

    SciTech Connect

    Shirabe, Komie; Takeshita, Masazumi; Landi, M.T.

    1995-08-01

    Hereditary methemoglobinemia with generalized deficiency of NADH-cytochrome b{sub 5} reductase (b{sub 5}R) (type II) is a rare disease characterized by severe developmental abnormalities, which often lead to premature death. Although the molecular relationship between the symptoms of this condition and the enzyme deficit are not understood, it is thought that an important cause is the loss of the lipid metabolizing activities of the endoplasmic reticulum-located reductase. However, the functions of the form located on outer mitochondrial membranes have not been considered previously. In this study, we have analyzed the gene of an Italian patient and identified a novel G{r_arrow}T transversion at the splice-acceptor site of the 9th exon, which results in the complete absence of immunologically detectable b{sub 5}R in blood cells and skin fibroblasts. In cultured fibroblasts of the patient, NADH-dependent cytochrome c reductase, ferricyanide reductase, and semidehydroascorbate reductase activities were severely reduced. The latter activity is known to be due to b{sub 5}R located on outer mitochondrial membranes. Thus, our results demonstrate that the reductase in its two membrane locations, endoplasmic reticulum and outer mitochondrial membranes, is the product of the same gene and suggest that a defect in ascorbate regeneration may contribute to the phenotype of hereditary methemoglobinemia of generalized type. 37 refs., 5 figs., 2 tabs.

  12. Perchlorate Reductase Is Distinguished by Active Site Aromatic Gate Residues.

    PubMed

    Youngblut, Matthew D; Tsai, Chi-Lin; Clark, Iain C; Carlson, Hans K; Maglaqui, Adrian P; Gau-Pan, Phonchien S; Redford, Steven A; Wong, Alan; Tainer, John A; Coates, John D

    2016-04-22

    Perchlorate is an important ion on both Earth and Mars. Perchlorate reductase (PcrAB), a specialized member of the dimethylsulfoxide reductase superfamily, catalyzes the first step of microbial perchlorate respiration, but little is known about the biochemistry, specificity, structure, and mechanism of PcrAB. Here we characterize the biophysics and phylogeny of this enzyme and report the 1.86-Å resolution PcrAB complex crystal structure. Biochemical analysis revealed a relatively high perchlorate affinity (Km = 6 μm) and a characteristic substrate inhibition compared with the highly similar respiratory nitrate reductase NarGHI, which has a relatively much lower affinity for perchlorate (Km = 1.1 mm) and no substrate inhibition. Structural analysis of oxidized and reduced PcrAB with and without the substrate analog SeO3 (2-) bound to the active site identified key residues in the positively charged and funnel-shaped substrate access tunnel that gated substrate entrance and product release while trapping transiently produced chlorate. The structures suggest gating was associated with shifts of a Phe residue between open and closed conformations plus an Asp residue carboxylate shift between monodentate and bidentate coordination to the active site molybdenum atom. Taken together, structural and mutational analyses of gate residues suggest key roles of these gate residues for substrate entrance and product release. Our combined results provide the first detailed structural insight into the mechanism of biological perchlorate reduction, a critical component of the chlorine redox cycle on Earth. PMID:26940877

  13. Molecular analysis of the 5 alpha-steroid reductase type 2 gene in a family with deficiency of the enzyme.

    PubMed

    Vilchis, F; Canto, P; Chávez, B; Ulloa-Aguirre, A; Méndez, J P

    1997-03-01

    This report describes the identification of a point mutation in the 5 alpha-reductase type 2 (5 alpha-SR2) gene from a family in which both sibs (6 and 3 years old) have steroid 5 alpha-reductase 2 deficiency. The five exons of the gene were individually amplified by the polymerase chain reaction (PCR) and analysed for single-strand conformation polymorphisms (SSCP) to detect mutations. Direct sequencing of the mutant PCR products demonstrated a single C-->T mutation, within exon 4, changing codon 227 from CGA (Arg) to TGA (premature termination signal). Both patients were homozygous for the mutation, but their parents were heterozygous. These results suggest that the mutation at codon 227 impairs normal 5 alpha-SR2 function, thus leading to the phenotypical expression of this rare enzymatic defect. PMID:9066886

  14. Purine salvage pathways of Bacillus subtilis and effect of guanine on growth of GMP reductase mutants.

    PubMed

    Endo, T; Uratani, B; Freese, E

    1983-07-01

    We have isolated numerous mutants containing mutations in the salvage pathways of purine synthesis. The mutations cause deficiencies in adenine phosphoribosyltransferase (adeF), in hypoxanthine-guanine phosphoribosyltransferase (guaF), in adenine deaminase (adeC), in inosine-guanosine phosphorylase, (guaP), and in GMP reductase (guaC). The physiological properties of mutants containing one or more of these mutations and corresponding enzyme measurements have been used to derive a metabolic chart of the purine salvage pathway of Bacillus subtilis. PMID:6408059

  15. Purine salvage pathways of Bacillus subtilis and effect of guanine on growth of GMP reductase mutants.

    PubMed Central

    Endo, T; Uratani, B; Freese, E

    1983-01-01

    We have isolated numerous mutants containing mutations in the salvage pathways of purine synthesis. The mutations cause deficiencies in adenine phosphoribosyltransferase (adeF), in hypoxanthine-guanine phosphoribosyltransferase (guaF), in adenine deaminase (adeC), in inosine-guanosine phosphorylase, (guaP), and in GMP reductase (guaC). The physiological properties of mutants containing one or more of these mutations and corresponding enzyme measurements have been used to derive a metabolic chart of the purine salvage pathway of Bacillus subtilis. PMID:6408059

  16. Fatty acyl-CoA reductase

    SciTech Connect

    Reiser, Steven E.; Somerville, Chris R.

    1998-12-01

    The present invention relates to bacterial enzymes, in particular to an acyl-CoA reductase and a gene encoding an acyl-CoA reductase, the amino acid and nucleic acid sequences corresponding to the reductase polypeptide and gene, respectively, and to methods of obtaining such enzymes, amino acid sequences and nucleic acid sequences. The invention also relates to the use of such sequences to provide transgenic host cells capable of producing fatty alcohols and fatty aldehydes.

  17. Recessive congenital methaemoglobinaemia: cytochrome b(5) reductase deficiency.

    PubMed

    Percy, Melanie J; Lappin, Terry R

    2008-05-01

    Some 60 years ago, Quentin Gibson reported the first hereditary disorder involving an enzyme when he deduced that familial methaemoglobinaemia was caused by an enzymatic lesion associated with the glycolysis pathway in red blood cells. This disorder, now known as recessive congenital methaemoglobinaemia (RCM), is caused by NADH-cytochrome b5 reductase (cb(5)r) deficiency. Two distinct clinical forms, types I and II, have been recognized, both characterized by cyanosis from birth. In type II, the cyanosis is accompanied by neurological impairment and reduced life expectancy. Cytochrome b(5) reductase is composed of one FAD and one NADH binding domain linked by a hinge region. It is encoded by the CYB5R3 (previously known as DIA1) gene and more than 40 mutations have been described, some of which are common to both types of RCM. Mutations associated with type II tend to cause incorrect splicing, disruption of the active site or truncation of the protein. At present the description of the sequence variants of cb(5)r in the literature is confusing, due to the use of two conventions which differ by one codon position. Herein we propose a new system for nomenclature of cb(5)r based on recommendations of the Human Genome Variation Society. The development of a heterologous expression system has allowed the impact of naturally occurring variants of cb(5)r to be assessed and has provided insight into the function of cb(5)r. PMID:18318771

  18. The prenyltransferase UBIAD1 is the target of geranylgeraniol in degradation of HMG CoA reductase

    PubMed Central

    Schumacher, Marc M; Elsabrouty, Rania; Seemann, Joachim; Jo, Youngah; DeBose-Boyd, Russell A

    2015-01-01

    Schnyder corneal dystrophy (SCD) is an autosomal dominant disorder in humans characterized by abnormal accumulation of cholesterol in the cornea. SCD-associated mutations have been identified in the gene encoding UBIAD1, a prenyltransferase that synthesizes vitamin K2. Here, we show that sterols stimulate binding of UBIAD1 to the cholesterol biosynthetic enzyme HMG CoA reductase, which is subject to sterol-accelerated, endoplasmic reticulum (ER)-associated degradation augmented by the nonsterol isoprenoid geranylgeraniol through an unknown mechanism. Geranylgeraniol inhibits binding of UBIAD1 to reductase, allowing its degradation and promoting transport of UBIAD1 from the ER to the Golgi. CRISPR-CAS9-mediated knockout of UBIAD1 relieves the geranylgeraniol requirement for reductase degradation. SCD-associated mutations in UBIAD1 block its displacement from reductase in the presence of geranylgeraniol, thereby preventing degradation of reductase. The current results identify UBIAD1 as the elusive target of geranylgeraniol in reductase degradation, the inhibition of which may contribute to accumulation of cholesterol in SCD. DOI: http://dx.doi.org/10.7554/eLife.05560.001 PMID:25742604

  19. A case of recurrent pancytopenia in a patient with acute promyelocytic leukemia on maintenance chemotherapy and concomitant methyltetrahydrofolate reductase and thiopurine S-methyltransferase mutation - review of literature.

    PubMed

    Keung, Yi-Kong; Keung, Lap-Woon; Hong-Lung Hu, Eddie

    2016-06-01

    Pharmacogenetics is a study of how genetic variation of an individual affects the drug response. We report a case of recurrent pancytopenia resulting from maintenance chemotherapy in a patient with acute promyelocytic leukemia and two pharmacogenetic mutations, namely, methylene tetrahydrofolate reductase C677T homozygous mutation and thiopurine methyltransferase mutation. PMID:25791511

  20. The nitrate-sensing NasST system regulates nitrous oxide reductase and periplasmic nitrate reductase in Bradyrhizobium japonicum.

    PubMed

    Sánchez, Cristina; Itakura, Manabu; Okubo, Takashi; Matsumoto, Takashi; Yoshikawa, Hirofumi; Gotoh, Aina; Hidaka, Masafumi; Uchida, Takafumi; Minamisawa, Kiwamu

    2014-10-01

    The soybean endosymbiont Bradyrhizobium japonicum is able to scavenge the greenhouse gas N2O through the N2O reductase (Nos). In previous research, N2O emission from soybean rhizosphere was mitigated by B. japonicum Nos(++) strains (mutants with increased Nos activity). Here, we report the mechanism underlying the Nos(++) phenotype. Comparative analysis of Nos(++) mutant genomes showed that mutation of bll4572 resulted in Nos(++) phenotype. bll4572 encodes NasS, the nitrate (NO3(-))-sensor of the two-component NasST regulatory system. Transcriptional analyses of nosZ (encoding Nos) and other genes from the denitrification process in nasS and nasST mutants showed that, in the absence of NO3(-) , nasS mutation induces nosZ and nap (periplasmic nitrate reductase) via nasT. NO3(-) addition dissociated the NasS-NasT complex in vitro, suggesting the release of the activator NasT. Disruption of nasT led to a marked decrease in nosZ and nap transcription in cells incubated in the presence of NO3(-). Thus, although NasST is known to regulate the NO3(-)-mediated response of NO3(-) assimilation genes in bacteria, our results show that NasST regulates the NO3(-) -mediated response of nosZ and napE genes, from the dissimilatory denitrification pathway, in B. japonicum. PMID:24947409

  1. Livedoid vasculopathy associated with combined prothrombin G20210A and factor V (Leiden) heterozygosity and MTHFR C677T homozygosity.

    PubMed

    Irani-Hakime, Noha A; Stephan, Farid; Kreidy, Raghid; Jureidini, Isabelle; Almawi, Wassim Y

    2008-08-01

    Livedoid vasculopathy (LV) is an occlusive thrombotic disease of lower extremities. A 34-year-old woman presented with 4-year history of recurrent necrotic and painful lesions with violaceous and purpuric border on both legs. Initial treatment with hydroxychloroquine, dapsone and prednisone were unsuccessful. Skin biopsy showed inflammatory infiltrate with epidermal necrosis. Prothrombin G20210A and factor V-Leiden heterozygosity, and MTHFR C677T homozygosity with hyperhomocysteinemia were confirmed. LV diagnosis was made; acetylsalicylic acid, folic acid, vitamin B12, and prednisone treatement resulted in complete healing. This is the first report on coexistence of prothrombin G20210A, factor V-Leiden, and homozygous MTHFR C677T with hyperhomocysteinemia in LV. PMID:18360788

  2. Dihydropteridine reductase from Escherichia coli.

    PubMed Central

    Vasudevan, S G; Shaw, D C; Armarego, W L

    1988-01-01

    A dihydropteridine reductase from Escherichia coli was purified to apparent homogeneity. It is a dimeric enzyme with identical subunits (Mr 27000) and a free N-terminal group. It can use NADH (Vmax./Km 3.36 s-1) and NADPH (Vmax./Km 1.07 s-1) when 6-methyldihydro-(6H)-pterin is the second substrate, as well as quinonoid dihydro-(6H)-biopterin (Vmax./Km 0.69 s-1), dihydro-(6H)-neopterin (Vmax./Km 0.58 s-1), dihydro-(6H)-monapterin 0.66 s-1), 6-methyldihydro-(6H)-pterin and cis-6,7-dimethyldihydro-(6H)-pterin (Vmax./Km 0.66 s-1) when NADH is the second substrate. The pure reductase has a yellow colour and contains bound FAD. The enzyme also has pterin-independent NADH and NADPH oxidoreductase activities when potassium ferricyanide is the electron acceptor. Images Fig. 2. PMID:3060113

  3. Association of MTHFR C677T Genotype With Ischemic Stroke Is Confined to Cerebral Small Vessel Disease Subtype

    PubMed Central

    Traylor, Matthew; Adib-Samii, Poneh; Thijs, Vincent; Sudlow, Cathie; Rothwell, Peter M.; Boncoraglio, Giorgio; Dichgans, Martin; Meschia, James; Maguire, Jane; Levi, Christopher; Rost, Natalia S.; Rosand, Jonathan; Hassan, Ahamad; Bevan, Steve; Markus, Hugh S.

    2016-01-01

    Background and Purpose— Elevated plasma homocysteine levels are associated with stroke. However, this might be a reflection of bias or confounding because trials have failed to demonstrate an effect from homocysteine lowering in stroke patients, although a possible benefit has been suggested in lacunar stroke. Genetic studies could potentially overcome these issues because genetic variants are inherited randomly and are fixed at conception. Therefore, we tested the homocysteine levels–associated genetic variant MTHFR C677T for association with magnetic resonance imaging–confirmed lacunar stroke and compared this with associations with large artery and cardioembolic stroke subtypes. Methods— We included 1359 magnetic resonance imaging–confirmed lacunar stroke cases, 1824 large artery stroke cases, 1970 cardioembolic stroke cases, and 14 448 controls, all of European ancestry. Furthermore, we studied 3670 ischemic stroke patients in whom white matter hyperintensities volume was measured. We tested MTHFR C677T for association with stroke subtypes and white matter hyperintensities volume. Because of the established association of homocysteine with hypertension, we additionally stratified for hypertension status. Results— MTHFR C677T was associated with lacunar stroke (P=0.0003) and white matter hyperintensity volume (P=0.04), but not with the other stroke subtypes. Stratifying the lacunar stroke cases for hypertension status confirmed this association in hypertensive individuals (P=0.0002), but not in normotensive individuals (P=0.30). Conclusions— MTHFR C677T was associated with magnetic resonance imaging–confirmed lacunar stroke, but not large artery or cardioembolic stroke. The association may act through increased susceptibility to, or interaction with, high blood pressure. This heterogeneity of association might explain the lack of effect of lowering homocysteine in secondary prevention trials which included all strokes. PMID:26839351

  4. Polymorphism 677C → T MTHFR gene in Mexican mothers of children with complex congenital heart disease.

    PubMed

    Balderrábano-Saucedo, Norma A; Sánchez-Urbina, Rocio; Sierra-Ramírez, José A; García-Hernández, Normand; Sánchez-Boiso, Adriana; Klunder-Klunder, Miguel; Arenas-Aranda, Diego; Bravo-Hernández, Gabriela; Noriega-Zapata, Penelope; Vizcaíno-Alarcón, Alfredo

    2013-01-01

    Congenital heart defects (CHD) are the third leading cause of death in children <1 year of age in Mexico where there is a high prevalence of the 677C → T polymorphism of the MTHFR gene. This is important because the homozygous 677T/T MTHFR gene and deficiency of folic acid (FA) intake have been associated with CHD. Our objective was to analyze the possible association between the genotype 677T/T of the MTHFR gene and supplementation of FA in Mexican women with the presence of complex CHD in their children. We analyzed genotypes of 31 mothers of children with complex CHD (group I) and 62 mothers of healthy children (group II) and investigated FA supplementation during pregnancy in both study groups. Allele frequencies in group I were 41.9 % for C and 58.1 % for T and 22.6 % for genotype frequencies CC, 38.7 % for CT, and 38.7 % for TT. Allele frequencies in group II were 63.7 % for C and 36.3 % for T and 38.7 % for genotype frequencies CC, 50 % for CT and 11.3 % for TT. Both populations are in Hardy-Weinberg equilibrium. Odds ratio for having a child with a complex CHD was 5.9, p = 0.008 (95 % CI 1.67; 20.63) for the TT genotype. FA supplementation at any time during pregnancy was 90.3 and 87.9 % in groups II and I respectively (p > 0.05). Association was found between the maternal genotype (677/TT MTHFR) with the presence of complex CHD in their offspring. No differences in FA supplementation during any stage were found between groups. PMID:22660520

  5. High-resolution melting curve analysis for genotyping of common SNP in MTHFR gene using fixed-cell suspension.

    PubMed

    Sinthuwiwat, Thivaratana; Poowasanpetch, Phanasit; Wongngamrungroj, Angsana; Promso, Somying; Auewarakul, Chirayu; Mooney, Sean; Tocharoentanaphol, Chintana

    2008-01-01

    Genetic variation in MTHFR might explain the interindividual differences in both therapeutic and toxic responses to the treatment of cancer and rheumatoid arthritis with methotrexate, and can be involved in the sensitivity of developing diseases like cancer and congenital anomalies. We investigated the common sequence variation, C677T, in the MTHFR gene in fixed-cell specimens archived after chromosomal analysis using a novel gene scanning method based on post PCR analysis of high-resolution melting curves (HRM). These fixed specimens were stored after routine chromosomal analysis for 1 year at -20 degrees C in a 3:1 methanol:acetic acid solution. The method revealed a distinct pattern between homozygous and heterozygous alleles. Sensitivity and specificity of the HRM based method were comparable to that obtained by a hybridization probe. While the success rate for genotyping of a common SNP in MTHFR was similar to the hybridization probe approach, the HRM based method was more cost-effective and had a shorter turnaround time. PMID:18725286

  6. GSTP1 and MTHFR polymorphisms are related with toxicity in breast cancer adjuvant anthracycline-based treatment.

    PubMed

    Zárate, R; González-Santigo, S; de la Haba, J; Bandres, E; Morales, R; Salgado, J; Gómez, A; Aranda, E; García-Foncillas, J

    2007-06-01

    We have analyzed several members of drug-metabolizing enzymes (DMEs) and other polymorphisms in genes implicated in tumor aggressivity regarding possible links between specific genetic variability in systemic drug bioavailability and toxicity in breast cancer patients treated with adjuvant anthracycline-based treatment. PCR-RFLP and sequencing analyses technique were used for evaluating fourteen previously identified polymorphisms in 94 patients. GSTP1A>G and MTHFR 1298A>C genotypes remained as significant predictors in a multivariate logistic regression analysis. GSTP1 polymorphism was linked to haematological GIII-IV toxicity (P = 0.044, HR= 6.4, 95% CI = 1.05 to 39. Increased and significant HR was obtained for MTHFR-1298 AC+CC group when non-haematological toxicities GIII-IV toxicities were evaluated (HR = 24; 95% CI = 2.3 to 254), P = 0.008. Our results suggest that GSTP1 and MTHFR genotypes may be consider relevant and independent factors of toxicity in adjuvant anthracycline-based treatment of breast cancer. PMID:17584018

  7. Polymorphisms of MTHFR Associated with Higher Relapse/Death Ratio and Delayed Weekly MTX Administration in Pediatric Lymphoid Malignancies

    PubMed Central

    Fukushima, Takashi; Sakai, Aiko; Suzuki, Ryoko; Nakajima-Yamaguchi, Ryoko; Kobayashi, Chie; Iwabuchi, Atsushi; Saito, Makoto; Yoshimi, Ai; Nakao, Tomohei; Kato, Keisuke; Tsuchida, Masahiro; Takahashi, Hideto; Koike, Kazutoshi; Kiyokawa, Nobutaka; Noguchi, Emiko; Sumazaki, Ryo

    2013-01-01

    Backgrounds. Outcome of childhood malignancy has been improved mostly due to the advances in diagnostic techniques and treatment strategies. While methotrexate (MTX) related polymorphisms have been under investigation in childhood malignancies, many controversial results have been offered. Objectives. To evaluate associations of polymorphisms related MTX metabolisms and clinical course in childhood lymphoid malignancies. Method. Eighty-two acute lymphoblastic leukemia and 21 non-Hodgkin's lymphoma children were enrolled in this study. Four single nucleotide polymorphisms in 2 genes (MTHFR (rs1801133/c.677C>T/p.Ala222Val and rs1801131/c.1298A>C/p.Glu429Ala) and SLCO1B1 (rs4149056/c.521T>C/p.V174A and rs11045879/c.1865+4846T>C)) were genotyped by Taqman PCR method or direct sequencing. Clinical courses were reviewed retrospectively. Results. No patient who had the AC/CC genotype of rs1801131 (MTHFR) had relapsed or died, in which distribution was statistically different among the AA genotype of rs1801131 (P = 0.004). Polymorphisms of SLCO1B1 (rs11045879 and rs4149056) were not correlated with MTX concentrations, adverse events, or disease outcome. Conclusions. Polymorphisms of MTHFR (rs1801131) could be the plausive candidate for prognostic predictor in childhood lymphoid malignancies. PMID:24386571

  8. The Frequency of Some Thrombophilic Mutations in Eastern Turkey

    PubMed Central

    Ozturk, Nurinnisa; Bakan, Ebubekir; Gul, Mehmet Ali; Bakan, Nuri; Sebin, Engin; Kiziltunc, Ahmet

    2016-01-01

    Objective: Factor V / Factor II / Methylenetetrahydrofolate reductase, gene polymorphisms are closely associated with thrombophilia. Regional frequencies of these mutations may show a characteristic state. The aim of our study was to evaluate the frequency of commonly seen Factor V / Factor II / Methylenetetrahydrofolate reductase gene polymorphisms in Eastern Turkey. Materials and Methods: In 433 patients sent to the laboratory with the suspicion of thrombophilia, using whole blood samples, an automated Nucleic Acid Test was used for mutation determinations in Verigene System. The kit module was designed to detect the Factor V G1691A / Factor II G20210A / Methylenetetrahydrofolate reductase gene C677T single nucleotide polymorphisms. Results: In 433 patients, 8.7% for Factor V G1691A polymorphisms were heterozygous genotype, 3.9% for Factor II G20210A polymorphisms were heterozygous genotype, and 43.9% for methylenetetrahydrofolate reductase 677C>T polymorphisms were heterozygous genotype and 3.0% homozygous mutation genotype. Conclusion: Detection of these commonly seen Factor V / Factor II / Methylenetetrahydrofolate reductase single nucleotide polymorphisms can help to identify patients in high risk group and to evaluate the interaction of genetic and acquired risk factors. Our findings suggest that commonly seen thrombophilic allele mutation frequency in our region is the same as the data reported in the literature. PMID:27026755

  9. DNA damage induction of ribonucleotide reductase.

    PubMed Central

    Elledge, S J; Davis, R W

    1989-01-01

    RNR2 encodes the small subunit of ribonucleotide reductase, the enzyme that catalyzes the first step in the pathway for the production of deoxyribonucleotides needed for DNA synthesis. RNR2 is a member of a group of genes whose activities are cell cycle regulated and that are transcriptionally induced in response to the stress of DNA damage. An RNR2-lacZ fusion was used to further characterize the regulation of RNR2 and the pathway responsible for its response to DNA damage. beta-Galactosidase activity in yeast strains containing the RNR2-lacZ fusion was inducible in response to DNA-damaging agents (UV light, 4-nitroquinoline-1-oxide [4-NQO], and methyl methanesulfonate [MMS]) and agents that block DNA replication (hydroxyurea [HU] and methotrexate) but not heat shock. When MATa cells were arrested in G1 by alpha-factor, RNR2 mRNA was still inducible by DNA damage, indicating that the observed induction can occur outside of S phase. In addition, RNR2 induction was not blocked by the presence of cycloheximide and is therefore likely to be independent of protein synthesis. A mutation, rnr2-314, was found to confer hypersensitivity to HU and increased sensitivity to MMS. In rnr2-314 mutant strains, the DNA damage stress response was found to be partially constitutive as well as hypersensitive to induction by HU but not MMS. The induction properties of RNR2 were examined in a rad4-2 mutant background; in this genetic background, RNR2 was hypersensitive to induction by 4-NQO but not MMS. Induction of the RNR2-lacZ fusion in a RAD(+) strain in response to 4-NQO was not enhanced by the presence of an equal number of rad4-2 cells that lacked the fusion, implying that the DNA damage stress response in cell autonomous. Images PMID:2513480

  10. Phenotypic classification of male pseudohermaphroditism due to steroid 5{alpha}-reductase 2 deficiency

    SciTech Connect

    Sinnecker, G.H.G; Hiort, O.; Kruse, K.; Dibbelt, L.

    1996-05-03

    Conversion of testosterone (T) to dihydrotestosterone (DHT) in genital tissue is catalysed by the enzyme 5{alpha}-reductase 2, which is encoded by the SRD5A2 gene. The potent androgen DHT is required for full masculinization of the external genitalia. Mutations of the SRD5A2 gene inhibit enzyme activity, diminish DHT formation, and hence cause masculinization defects of varying degree. The classical syndrome, formerly described as pseudovaginal perineoscrotal hypospadias, is characterized by a predominantly female phenotype at birth and significant virilization without gynecomastia at puberty. We investigated nine patients with steroid 5{alpha}-reductase 2 deficiency (SRD). T/DHT-ratios were highly increased in the classical syndrome, but variable in the less severe affected patients. Mutations in the SRD5A2 gene had been characterized using PCR-SSCP analysis and direct DNA sequencing. A small deletion was encountered in two patients, while all other patients had single base mutations which result in amino acid substitutions. We conclude that phenotypes may vary widely in patients with SRD5A2 gene mutations spanning the whole range from completely female to normal male without distinctive clinical signs of the disease. Hence, steroid 5{alpha}-reductase deficiency should be considered not only in sex reversed patients with female or ambiguous phenotypes, but also in those with mild symptoms of undermasculinization as encountered in patients with hypospadias and/or micropenis. A classification based on the severity of the masculinization defect may be used for correlation of phenotypes with enzyme activities and genotypes, and for comparisons of phenotypes between different patients as the basis for clinical decisions to be made in patients with pseudohermaphroditism due to steroid 5{alpha}-reductase 2 deficiency. 22 refs., 2 figs., 2 tabs.

  11. An electrogenic nitric oxide reductase.

    PubMed

    Al-Attar, Sinan; de Vries, Simon

    2015-07-22

    Nitric oxide reductases (Nors) are members of the heme-copper oxidase superfamily that reduce nitric oxide (NO) to nitrous oxide (N₂O). In contrast to the proton-pumping cytochrome oxidases, Nors studied so far have neither been implicated in proton pumping nor have they been experimentally established as electrogenic. The copper-A-dependent Nor from Bacillus azotoformans uses cytochrome c₅₅₁ as electron donor but lacks menaquinol activity, in contrast to our earlier report (Suharti et al., 2001). Employing reduced phenazine ethosulfate (PESH) as electron donor, the main NO reduction pathway catalyzed by Cu(A)Nor reconstituted in liposomes involves transmembrane cycling of the PES radical. We show that Cu(A)Nor reconstituted in liposomes generates a proton electrochemical gradient across the membrane similar in magnitude to cytochrome aa₃, highlighting that bacilli using Cu(A)Nor can exploit NO reduction for increased cellular ATP production compared to organisms using cNor. PMID:26149211

  12. Tetrathionate reductase of Salmonella thyphimurium: a molybdenum containing enzyme

    SciTech Connect

    Hinojosa-Leon, M.; Dubourdieu, M.; Sanchez-Crispin, J.A.; Chippaux, M.

    1986-04-29

    Use of radioactive molybdenum demonstrates that the tetrathionate reductase of Salmonella typhimurium is a molydenum containing enzyme. It is proposed that this enzyme shares with other molybdo-proteins, such as nitrate reductase, a common molybdenum containing cofactor the defect of which leads to the loss of the tetrathionate reductase and nitrate reductase activities.

  13. Evolution Alters the Enzymatic Reaction Coordinate of Dihydrofolate Reductase

    PubMed Central

    2015-01-01

    How evolution has affected enzyme function is a topic of great interest in the field of biophysical chemistry. Evolutionary changes from Escherichia coli dihydrofolate reductase (ecDHFR) to human dihydrofolate reductase (hsDHFR) have resulted in increased catalytic efficiency and an altered dynamic landscape in the human enzyme. Here, we show that a subpicosecond protein motion is dynamically coupled to hydride transfer catalyzed by hsDHFR but not ecDHFR. This motion propagates through residues that correspond to mutational events along the evolutionary path from ecDHFR to hsDHFR. We observe an increase in the variability of the transition states, reactive conformations, and times of barrier crossing in the human system. In the hsDHFR active site, we detect structural changes that have enabled the coupling of fast protein dynamics to the reaction coordinate. These results indicate a shift in the DHFR family to a form of catalysis that incorporates rapid protein dynamics and a concomitant shift to a more flexible path through reactive phase space. PMID:25369552

  14. Genetics Home Reference: sepiapterin reductase deficiency

    MedlinePlus

    ... reductase enzyme. This enzyme is involved in the production of a molecule called tetrahydrobiopterin (also known as ... is responsible for the last step in the production of tetrahydrobiopterin. Tetrahydrobiopterin helps process several building blocks ...

  15. Divergent evolution of protein conformational dynamics in dihydrofolate reductase.

    PubMed

    Bhabha, Gira; Ekiert, Damian C; Jennewein, Madeleine; Zmasek, Christian M; Tuttle, Lisa M; Kroon, Gerard; Dyson, H Jane; Godzik, Adam; Wilson, Ian A; Wright, Peter E

    2013-11-01

    Molecular evolution is driven by mutations, which may affect the fitness of an organism and are then subject to natural selection or genetic drift. Analysis of primary protein sequences and tertiary structures has yielded valuable insights into the evolution of protein function, but little is known about the evolution of functional mechanisms, protein dynamics and conformational plasticity essential for activity. We characterized the atomic-level motions across divergent members of the dihydrofolate reductase (DHFR) family. Despite structural similarity, Escherichia coli and human DHFRs use different dynamic mechanisms to perform the same function, and human DHFR cannot complement DHFR-deficient E. coli cells. Identification of the primary-sequence determinants of flexibility in DHFRs from several species allowed us to propose a likely scenario for the evolution of functionally important DHFR dynamics following a pattern of divergent evolution that is tuned by cellular environment. PMID:24077226

  16. Structure of a bacterial homologue of vitamin K epoxide reductase

    SciTech Connect

    Li, Weikai; Schulman, Sol; Dutton, Rachel J.; Boyd, Dana; Beckwith, Jon; Rapoport, Tom A.

    2010-03-19

    Vitamin K epoxide reductase (VKOR) generates vitamin K hydroquinone to sustain {gamma}-carboxylation of many blood coagulation factors. Here, we report the 3.6 {angstrom} crystal structure of a bacterial homologue of VKOR from Synechococcus sp. The structure shows VKOR in complex with its naturally fused redox partner, a thioredoxin-like domain, and corresponds to an arrested state of electron transfer. The catalytic core of VKOR is a four transmembrane helix bundle that surrounds a quinone, connected through an additional transmembrane segment with the periplasmic thioredoxin-like domain. We propose a pathway for how VKOR uses electrons from cysteines of newly synthesized proteins to reduce a quinone, a mechanism confirmed by in vitro reconstitution of vitamin K-dependent disulphide bridge formation. Our results have implications for the mechanism of the mammalian VKOR and explain how mutations can cause resistance to the VKOR inhibitor warfarin, the most commonly used oral anticoagulant.

  17. Divergent evolution of protein conformational dynamics in dihydrofolate reductase

    PubMed Central

    Bhabha, Gira; Ekiert, Damian C.; Jennewein, Madeleine; Zmasek, Christian M.; Tuttle, Lisa M.; Kroon, Gerard; Dyson, H. Jane; Godzik, Adam; Wilson, Ian A.; Wright, Peter E.

    2013-01-01

    Molecular evolution is driven by mutations, which may affect the fitness of an organism and are then subject to natural selection or genetic drift. Analysis of primary protein sequences and tertiary structures has yielded valuable insights into the evolution of protein function, but little is known about evolution of functional mechanisms, protein dynamics and conformational plasticity essential for activity. We characterized the atomic-level motions across divergent members of the dihydrofolate reductase (DHFR) family. Despite structural similarity, E. coli and human DHFRs use different dynamic mechanisms to perform the same function, and human DHFR cannot complement DHFR-deficient E. coli cells. Identification of the primary sequence determinants of flexibility in DHFRs from several species allowed us to propose a likely scenario for the evolution of functionally important DHFR dynamics, following a pattern of divergent evolution that is tuned by the cellular environment. PMID:24077226

  18. A dissimilatory nitrite reductase in Paracoccus halodenitrificans

    NASA Technical Reports Server (NTRS)

    Grant, M. A.; Hochstein, L. I.

    1984-01-01

    Paracoccus halodenitrificans produced a membrane-associated nitrite reductase. Spectrophotometric analysis showed it to be associated with a cd-cytochrome and located on the inner side of the cytoplasmic membrane. When supplied with nitrite, membrane preparations produced nitrous oxide and nitric oxide in different ratios depending on the electron donor employed. The nitrite reductase was maximally active at relatively low concentrations of sodium chloride and remained attached to the membranes at 100 mM sodium chloride.

  19. Sequential backbone resonance assignments of the E. coli dihydrofolate reductase Gly67Val mutant: folate complex.

    PubMed

    Puthenpurackal Narayanan, Sunilkumar; Maeno, Akihiro; Wada, Yuji; Tate, Shin-Ichi; Akasaka, Kazuyuki

    2016-04-01

    Occasionally, a mutation in an exposed loop region causes a significant change in protein function and/or stability. A single mutation Gly67Val of E. coli dihydrofolate reductase (DHFR) in the exposed CD loop is such an example. We have carried out the chemical shift assignments for H(N), N(H), C(α) and C(β) atoms of the Gly67Val mutant of E. coli DHFR complexed with folate at pH 7.0, 35 °C, and then evaluated the H(N), N(H), C(α) and C(β) chemical shift changes caused by the mutation. The result indicates that, while the overall secondary structure remains the same, the single mutation Gly67Val causes site-specific conformational changes of the polypeptide backbone restricted around the adenosine-binding subdomain (residues 38-88) and not in the distant catalytic domain. PMID:26482924

  20. Multiple aldehyde reductases of human brain.

    PubMed

    Hoffman, P L; Wermuth, B; von Wartburg, J P

    1980-01-01

    Human brain contains four forms of aldehyde reducing enzymes. One major activity, designated AR3, has properties indicating its identity with the NADPH-dependent aldehyde reductase, EC 1.1.1.2. The other major form of human brain enzyme, AR1, which is also NADPH-dependent, reduces both aldehyde and ketone-containing substrates, including vitamin K3 (menadione) and daunorubicin, a cancer chemotherapeutic agent. This enzyme is very sensitive to inhibition by the flavonoids quercitrin and quercetine, and may be analogous to a daunorubicin reductase previously described in liver of other species. One minor form of human brain aldehyde reductase, AR2, demonstrates substrate specificity and inhibitor sensitivity which suggest its similarity to aldose reductases found in lens and other tissues of many species. This enzyme, which can also use NADH as cofactor to some extent, is the most active in reducing the aldehyde derivatives of the biogenic amines. The fourth human brain enzyme ("SSA reductase") differs from the other forms in its ability to use NADH as well as or better than NADPH as cofactor, and in its molecular weight, which is nearly twice that of the other forms. It is quite specific for succinic semialdehyde (SSA) as substrate, and was found to be significantly inhibited only by quercetine and quercitrin. AR3 can also reduce SSA, and both enzymes may contribute to the production of gamma-hydroxybutyric acid in vivo. These results indicate that the human brain aldehyde reductases can play relatively specific physiologic roles. PMID:7424738

  1. Thioredoxin Reductase and its Inhibitors

    PubMed Central

    Saccoccia, Fulvio; Angelucci, Francesco; Boumis, Giovanna; Carotti, Daniela; Desiato, Gianni; Miele, Adriana E; Bellelli, Andrea

    2014-01-01

    Thioredoxin plays a crucial role in a wide number of physiological processes, which span from reduction of nucleotides to deoxyriboucleotides to the detoxification from xenobiotics, oxidants and radicals. The redox function of Thioredoxin is critically dependent on the enzyme Thioredoxin NADPH Reductase (TrxR). In view of its indirect involvement in the above mentioned physio/pathological processes, inhibition of TrxR is an important clinical goal. As a general rule, the affinities and mechanisms of binding of TrxR inhibitors to the target enzyme are known with scarce precision and conflicting results abound in the literature. A relevant analysis of published results as well as the experimental procedures is therefore needed, also in view of the critical interest of TrxR inhibitors. We review the inhibitors of TrxR and related flavoreductases and the classical treatment of reversible, competitive, non competitive and uncompetitive inhibition with respect to TrxR, and in some cases we are able to reconcile contradictory results generated by oversimplified data analysis. PMID:24875642

  2. Characterization of thyroidal glutathione reductase

    SciTech Connect

    Raasch, R.J.

    1989-01-01

    Glutathione levels were determined in bovine and rat thyroid tissue by enzymatic conjugation with 1-chloro-2,4-dinitrobenzene using glutathione S-transferase. Bovine thyroid tissue contained 1.31 {+-} 0.04 mM reduced glutathione (GSH) and 0.14 {+-} 0.02 mM oxidized glutathione (GSSG). In the rat, the concentration of GSH was 2.50 {+-} 0.05 mM while GSSG was 0.21 {+-} 0.03 mM. Glutathione reductase (GR) was purified from bovine thyroid to electrophoretic homogeneity by ion exchange, affinity and molecular exclusion chromatography. A molecular weight range of 102-109 kDa and subunit size of 55 kDa were determined for GR. Thyroidal GR was shown to be a favoprotein with one FAD per subunit. The Michaelis constants of bovine thyroidal GR were determined to be 21.8 {mu}M for NADPH and 58.8 {mu}M for GSSG. The effect of thyroid stimulating hormone (TSH) and thyroxine (T{sub 4}) on in vivo levels of GR and glucose 6-phosphate dehydrogenase were determined in rat thyroid homogenates. Both enzymes were stimulated by TSH treatment and markedly reduced following T{sub 4} treatment. Lysosomal hydrolysis of ({sup 125}I)-labeled and unlabeled thyroglobulin was examined using size exclusion HPLC.

  3. Meta-analysis supports association of a functional SNP (rs1801133) in the MTHFR gene with Parkinson's disease.

    PubMed

    Zhu, Zhi-Gang; Ai, Qing-Long; Wang, Wen-Min; Xiao, Zhi-Cheng

    2013-11-15

    The MTHFR is a candidate risk gene for Parkinson's disease (PD), and a functional SNP (rs1801133) in the coding region of this gene has been investigated for the associations with the illness extensively among worldwide populations, but overall the results were inconsistent. Here, to assess the relationship between rs1801133 and risk of PD in general populations, we conducted a systematic meta-analysis by combining all available case-control samples in European and Asian populations, with a total of 1820 PD cases and 7530 healthy controls, and the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) for rs1801133 and PD were calculated using the Mantel-Haenszel method with a fixed-effect model. Overall, rs1801133 was significantly associated with the risk of PD (allelic model, pooled OR=1.212 for T allele, 95% CI=1.097-1.340, p-value=0.0002). When stratifying for ethnicity, significant association was also observed in European (allelic model, pooled OR=1.187 for T allele, 95% CI=1.058-1.332, p-value=0.004) and Asian samples (allelic model, pooled OR=1.293 for T allele, 95% CI=1.058-1.580, p-value=0.012) respectively. In addition, rs1801133 was also significantly associated with MTHFR mRNA expression in both CEU (European, p-value=0.0149) and CHB (Chinese, p-value=0.0178) HapMap populations. Collectively, our meta-analysis suggests that rs1801133 is significantly associated with susceptibility to PD in European and Asian populations, and MTHFR is likely an authentic risk gene for PD. PMID:23916622

  4. Association between the MTHFR C677T polymorphism and risk of cancer: evidence from 446 case-control studies.

    PubMed

    Xie, Shu-Zhe; Liu, Zhi-Zhong; Yu, Jun-hua; Liu, Li; Wang, Wei; Xie, Dao-Lin; Qin, Jiang-Bo

    2015-11-01

    Many molecular epidemiological studies have been performed to explore the association between MTHFR C677T polymorphism and cancer risk in diverse populations. However, the results were inconsistent. Hence, we performed a meta-analysis to investigate the association between cancer risk and MTHFR C677T (150,086 cases and 200,699 controls from 446 studies) polymorphism. Overall, significantly increased cancer risk was found when all eligible studies were pooled into the meta-analysis. In the further stratified and sensitivity analyses, significantly increased breast cancer risk was found in Asians and Indians, significantly decreased colon cancer risk was found, significantly decreased colorectal cancer risk was found in male population, significantly increased gastric cancer risk was found in Caucasians and Asians, significantly increased hepatocellular cancer risk was found in Asians, significantly decreased adult acute lymphoblastic leukemia (AALL) risk was found in Caucasians, significantly decreased childhood acute lymphoblastic leukemia (CALL) risk was found in Asians, and significantly increased multiple myeloma and NHL risk was found in Caucasians. In summary, this meta-analysis suggests that MTHFR C677T polymorphism is associated with increased breast cancer, gastric cancer, and hepatocellular cancer risk in Asians, is associated with increased gastric cancer, multiple myeloma, and NHL risk in Caucasians, is associated with decreased AALL risk in Caucasians, is associated with decreased CALL risk in Asians, is associated with increased breast cancer risk in Asians, is associated with decreased colon cancer risk, and is associated with decreased colorectal cancer risk in male population. Moreover, this meta-analysis also points out the importance of new studies, such as Asians of HNC, Asians of lung cancer, and Indians of breast cancer, because they had high heterogeneity in this meta-analysis (I(2) > 75%). PMID:26081619

  5. A phase II trial of sequential ribonucleotide reductase inhibition in aggressive myeloproliferative neoplasms

    PubMed Central

    Zeidner, Joshua F.; Karp, Judith E.; Blackford, Amanda L.; Smith, B. Douglas; Gojo, Ivana; Gore, Steven D.; Levis, Mark J.; Carraway, Hetty E.; Greer, Jacqueline M.; Ivy, S. Percy; Pratz, Keith W.; McDevitt, Michael A.

    2014-01-01

    Myeloproliferative neoplasms are a varied group of disorders that can have prolonged chronic phases, but eventually accelerate and can transform into a secondary acute myeloid leukemia that is ultimately fatal. Triapine is a novel inhibitor of the M2 subunit of ribonucleotide reductase. Sequential inhibition of ribonucleotide reductase with triapine and an M1 ribonucleotide reductase inhibitor (fludarabine) was noted to be safe, and led to a 29% complete plus partial response rate in myeloproliferative neoplasms. This article reports the findings of a phase II trial of triapine (105 mg/m2/day) followed by fludarabine (30 mg/m2/day) daily for 5 consecutive days in 37 patients with accelerated myeloproliferative neoplasms and secondary acute myeloid leukemia. The overall response rate was 49% (18/37), with a complete remission rate of 24% (9/37). Overall response rates and complete remissions were seen in all disease subsets, including secondary acute myeloid leukemia, in which the overall response rate and complete remission rate were 48% and 33%, respectively. All patients with known JAK2 V617F mutations (6/6) responded. The median overall survival of the entire cohort was 6.9 months, with a median overall survival of both overall responders and complete responders of 10.6 months. These data further demonstrate the promise of sequential inhibition of ribonucleotide reductase in patients with accelerated myeloproliferative neoplasms and secondary acute myeloid leukemia. This study was registered with clinicaltrials.gov (NCT00381550). PMID:24362550

  6. Risk of venous thromboembolism associated with single and combined effects of Factor V Leiden, Prothrombin 20210A and Methylenetethraydrofolate reductase C677T: a meta-analysis involving over 11,000 cases and 21,000 controls

    PubMed Central

    Simone, B; De Stefano, V; Leoncini, E; Zacho, J; Martinelli, I; Emmerich, J; Rossi, E; Folsom, AR; Almawi, WY; Scarabin, PY; den Heijer, M; Cushman, M; Penco, S; Vaya, A; Angchaisuksiri, P; Okumus, G; Gemmati, D; Cima, S; Akar, N; Oguzulgen, KI; Ducros, V; Lichy, C; Fernandez-Miranda, C; Szczeklik, A; Nieto, JA; Torres, JD; Le Cam-Duchez, V; Ivanov, P; Cantu, C; Shmeleva, VM; Stegnar, M; Ogunyemi, D; Eid, SS; Nicolotti, N; De Feo, E; Ricciardi, W; Boccia, S

    2014-01-01

    BACKGROUND Genetic and environmental factors interact in determining the risk of venous thromboembolism (VTE). The risk associated with the polymorphic variants G1691A of factor V (Factor V Leiden,FVL), G20210A of prothrombin (PT20210A) and C677T of methylentetrahydrofolate reductase (C677T MTHFR) genes has been investigated in many studies. METHODS We performed a pooled analysis of case-control and cohort studies investigating in adults the association between each variant and VTE, published on Pubmed, Embase or Google through January 2010. Authors of eligible papers, were invited to provide all available individual data for the pooling. The Odds Ratio (OR) for first VTE associated with each variant, individually and combined with the others, were calculated with a random effect model, in heterozygotes and homozygotes (dominant model for FVL and PT20210A; recessive for C677T MTHFR). RESULTS We analysed 31 databases, including 11,239 cases and 21,521 controls. No significant association with VTE was found for homozygous C677T MTHFR (OR: 1.38; 95% confidence intervals [CI]: 0.98–1.93), whereas the risk was increased in carriers of either heterozygous FVL or PT20210 (OR=4.22; 95% CI: 3.35–5.32; and OR=2.79;95% CI: 2.25–3.46, respectively), in double hterozygotes (OR=3.42; 95%CI 1.64-7.13), and in homozygous FVL or PT20210A (OR=11.45; 95%CI: 6.79-19.29; and OR: 2.79; 95%CI: 2.25 – 3.46, respectively). The stratified analyses showed a stronger effect of FVL on individuals ≤45 years (p-value for interaction = 0.036) and of PT20210A in women using oral contraceptives (p-value for interaction = 0.045). CONCLUSIONS In this large pooled analysis, inclusive of large studies like MEGA, no effect was found for C677T MTHFR on VTE; FVL and PT20210A were confirmed to be moderate risk factors. Notably, double carriers of the two genetic variants produced an impact on VTE risk significantly increased but weaker than previously thought. PMID:23900608

  7. Structural and mechanistic insights on nitrate reductases.

    PubMed

    Coelho, Catarina; Romão, Maria João

    2015-12-01

    Nitrate reductases (NR) belong to the DMSO reductase family of Mo-containing enzymes and perform key roles in the metabolism of the nitrogen cycle, reducing nitrate to nitrite. Due to variable cell location, structure and function, they have been divided into periplasmic (Nap), cytoplasmic, and membrane-bound (Nar) nitrate reductases. The first crystal structure obtained for a NR was that of the monomeric NapA from Desulfovibrio desulfuricans in 1999. Since then several new crystal structures were solved providing novel insights that led to the revision of the commonly accepted reaction mechanism for periplasmic nitrate reductases. The two crystal structures available for the NarGHI protein are from the same organism (Escherichia coli) and the combination with electrochemical and spectroscopic studies also lead to the proposal of a reaction mechanism for this group of enzymes. Here we present an overview on the current advances in structural and functional aspects of bacterial nitrate reductases, focusing on the mechanistic implications drawn from the crystallographic data. PMID:26362109

  8. Atomic Structure of Salutaridine Reductase from the Opium Poppy (Papaver somniferum)

    SciTech Connect

    Higashi, Yasuhiro; Kutchan, Toni M.; Smith, Thomas J.

    2011-11-18

    The opium poppy (Papaver somniferum L.) is one of the oldest known medicinal plants. In the biosynthetic pathway for morphine and codeine, salutaridine is reduced to salutaridinol by salutaridine reductase (SalR; EC 1.1.1.248) using NADPH as coenzyme. Here, we report the atomic structure of SalR to a resolution of {approx}1.9 {angstrom} in the presence of NADPH. The core structure is highly homologous to other members of the short chain dehydrogenase/reductase family. The major difference is that the nicotinamide moiety and the substrate-binding pocket are covered by a loop (residues 265-279), on top of which lies a large 'flap'-like domain (residues 105-140). This configuration appears to be a combination of the two common structural themes found in other members of the short chain dehydrogenase/reductase family. Previous modeling studies suggested that substrate inhibition is due to mutually exclusive productive and nonproductive modes of substrate binding in the active site. This model was tested via site-directed mutagenesis, and a number of these mutations abrogated substrate inhibition. However, the atomic structure of SalR shows that these mutated residues are instead distributed over a wide area of the enzyme, and many are not in the active site. To explain how residues distal to the active site might affect catalysis, a model is presented whereby SalR may undergo significant conformational changes during catalytic turnover.

  9. High dose methotrexate treatment in childhood ALL: pilot study on the impact of the MTHFR 677C>T and 1298A>C polymorphisms on MTX-related toxicity.

    PubMed

    Haase, R; Elsner, K; Merkel, N; Stiefel, M; Mauz-Körholz, C; Kramm, C M; Körholz, D

    2012-04-01

    Methotrexate (MTX) is commonly administered in high doses for treatment of childhood acute lymphoblastic leukemia (ALL). The aim of this analysis was to study the influence of 2 common MTHFR polymorphisms (MTHFR 677C>T and 1298 A>C) on MTX toxicity in children with ALL.Retrospective analysis of 129 MTX courses in 34 pediatric patients with ALL.677C>T variants (CT or TT) were found in 19 (14 heterozygous, 5 homozygous) and 1298A>C variants (AC or CC) in 20 (16 heterozygous, 4 homozygous) patients. The MTHFR 677C>T wild type was associated with an increased frequency of grade III and IV leukopenia (60% vs. 31%, p<0.05) compared to the variants. The rate of severe infections (21% vs. 0%, p<0.05) and grade III-IV anemia (26% vs. 5%, p<0.05) was increased in carriers of the MTHFR 677C>T wild type compared to patients with the TT variant. Grade III-IV anemia was more frequent in patients with the MTHFR 1298A>C CC variant compared to the wild type (56% vs. 21%, p<0.05). The differences were not significant in a patient-based analysis.MTX related toxicity might be influenced by the MTHFR 677C>T or the MTHFR 1298A>C polymorphisms. Differences in MTX toxicity are only partially explainable by these 2 polymorphisms. PMID:22513795

  10. Lack of association between the methylenetetrahydropholate reductase gene A1298C polymorphism and neural tube defects in a Turkish study group.

    PubMed

    Yildiz, S H; Ozdemir Erdogan, M; Solak, M; Eser, O; Arıkan Terzi, E S; Eser, B; Kocabaş, V; Aslan, A

    2016-01-01

    The etiology underlying neural tube defects (NTDs) is not fully understood and is believed to involve a complex milieu of genetic and environmental factors. The A1298C polymorphism in the methylenetetrahydropholate reductase gene (MTHFR) has been associated with mild risk for NTDs. In this study, the genotype distribution of the MTHFR gene A1298C polymorphism and the levels of serum homocysteine, vitamin B12, and folate were evaluated in 33 children with NTDs, their mothers, and 46 healthy controls. Genotyping of the A1298C polymorphism was performed by real-time polymerase chain reaction. The A and C allele frequencies in children with NTDs and their mothers were similar to controls (P = 0.160). The 1298AA and 1298CC genotype frequencies (P = 0.551 and 0.062, respectively) in children with NTDs and their mothers did not differ from controls. On the other hand, the 1298AC genotype frequencies in children with NTDs and their mothers were significantly different from controls (P = 0.025). The genotype frequency of 1298AC was lower in children with NTDs than in controls. There was no significant association between clinical distribution of NTDs and 1298AA/AC/CC genotypes (P > 0.05). Serum vitamin B12 levels were higher in children with NTDs than their mothers and controls (P = 0.001). There were no differences among serum homocysteine and folate levels in all groups (P = 0.494 and 0.141, respectively). Both genetic and nutritional factors are important in the etiology of NTDs. Thus, the A1298C polymorphism cannot be regarded as a major risk factor for NTDs. PMID:27323133

  11. Respiratory arsenate reductase as a bidirectional enzyme

    USGS Publications Warehouse

    Richey, C.; Chovanec, P.; Hoeft, S.E.; Oremland, R.S.; Basu, P.; Stolz, J.F.

    2009-01-01

    The haloalkaliphilic bacterium Alkalilimnicola ehrlichii is capable of anaerobic chemolithoautotrophic growth by coupling the oxidation of arsenite (As(III)) to the reduction of nitrate and carbon dioxide. Analysis of its complete genome indicates that it lacks a conventional arsenite oxidase (Aox), but instead possesses two operons that each encode a putative respiratory arsenate reductase (Arr). Here we show that one homolog is expressed under chemolithoautotrophic conditions and exhibits both arsenite oxidase and arsenate reductase activity. We also demonstrate that Arr from two arsenate respiring bacteria, Alkaliphilus oremlandii and Shewanella sp. strain ANA-3, is also biochemically reversible. Thus Arr can function as a reductase or oxidase. Its physiological role in a specific organism, however, may depend on the electron potentials of the molybdenum center and [Fe–S] clusters, additional subunits, or constitution of the electron transfer chain. This versatility further underscores the ubiquity and antiquity of microbial arsenic metabolism.

  12. Respiratory arsenate reductase as a bidirectional enzyme

    SciTech Connect

    Richey, Christine; Chovanec, Peter; Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 ; Hoeft, Shelley E.; Oremland, Ronald S.; Basu, Partha; Stolz, John F.

    2009-05-01

    The haloalkaliphilic bacterium Alkalilimnicola ehrlichii is capable of anaerobic chemolithoautotrophic growth by coupling the oxidation of arsenite (As(III)) to the reduction of nitrate and carbon dioxide. Analysis of its complete genome indicates that it lacks a conventional arsenite oxidase (Aox), but instead possesses two operons that each encode a putative respiratory arsenate reductase (Arr). Here we show that one homolog is expressed under chemolithoautotrophic conditions and exhibits both arsenite oxidase and arsenate reductase activity. We also demonstrate that Arr from two arsenate respiring bacteria, Alkaliphilus oremlandii and Shewanella sp. strain ANA-3, is also biochemically reversible. Thus Arr can function as a reductase or oxidase. Its physiological role in a specific organism, however, may depend on the electron potentials of the molybdenum center and [Fe-S] clusters, additional subunits, or constitution of the electron transfer chain. This versatility further underscores the ubiquity and antiquity of microbial arsenic metabolism.

  13. Phylogenomics of Mycobacterium Nitrate Reductase Operon.

    PubMed

    Huang, Qinqin; Abdalla, Abualgasim Elgaili; Xie, Jianping

    2015-07-01

    NarGHJI operon encodes a nitrate reductase that can reduce nitrate to nitrite. This process enhances bacterial survival by nitrate respiration under anaerobic conditions. NarGHJI operon exists in many bacteria, especially saprophytic bacteria living in soil which play a key role in the nitrogen cycle. Most actinomycetes, including Mycobacterium tuberculosis, possess NarGHJI operons. M. tuberculosis is a facultative intracellular pathogen that expands in macrophages and has the ability to persist in a non-replicative form in granuloma lifelong. Nitrogen and nitrogen compounds play crucial roles in the struggle between M. tuberculosis and host. M. tuberculosis can use nitrate as a final electron acceptor under anaerobic conditions to enhance its survival. In this article, we reviewed the mechanisms regulating nitrate reductase expression and affecting its activity. Potential genes involved in regulating the nitrate reductase expression in M. tuberculosis were identified. The conserved NarG might be an alternative mycobacterium taxonomic marker. PMID:25980349

  14. Optical observation of correlated motions in dihydrofolate reductase

    NASA Astrophysics Data System (ADS)

    Xu, Mengyang; Niessen, Katherine; Pace, James; Cody, Vivian; Markelz, Andrea

    2015-03-01

    Enzyme function relies on its structural flexibility to make conformational changes for substrate binding and product release. An example of a metabolic enzyme where such structural changes are vital is dihydrofolate reductase (DHFR). DHFR is essential in both prokaryotes and eukaryotes for the nucleotide biosynthesis by catalyzing the reduction of dihydrofolate to tetrahydrofolate. NMR dynamical measurements found large amplitude fast dynamics that could indicate rigid-body, twisting-hinge motion for ecDHFR that may mediate flux. The role of such long-range correlated motions in function was suggested by the observed sharp decrease in enzyme activity for the single point mutation G121V, which is remote from active sites. This decrease in activity may be caused by the mutation interfering with the long-range intramolecular vibrations necessary for rapid access to functional configurations. We use our new technique of crystal anisotropy terahertz microscopy (CATM), to observe correlated motions in ecDHFR crystals with the bonding of NADPH and methotrexate. We compare the measured intramolecular vibrational spectrum with calculations using normal mode analysis.

  15. Loop interactions during catalysis by dihydrofolate reductase from Moritella profunda.

    PubMed

    Behiry, Enas M; Evans, Rhiannon M; Guo, Jiannan; Loveridge, E Joel; Allemann, Rudolf K

    2014-07-29

    Dihydrofolate reductase (DHFR) is often used as a model system to study the relation between protein dynamics and catalysis. We have studied a number of variants of the cold-adapted DHFR from Moritella profunda (MpDHFR), in which the catalytically important M20 and FG loops have been altered, and present a comparison with the corresponding variants of the well-studied DHFR from Escherichia coli (EcDHFR). Mutations in the M20 loop do not affect the actual chemical step of transfer of hydride from reduced nicotinamide adenine dinucleotide phosphate to the substrate 7,8-dihydrofolate in the catalytic cycle in either enzyme; they affect the steady state turnover rate in EcDHFR but not in MpDHFR. Mutations in the FG loop also have different effects on catalysis by the two DHFRs. Despite the two enzymes most likely sharing a common catalytic cycle at pH 7, motions of these loops, known to be important for progression through the catalytic cycle in EcDHFR, appear not to play a significant role in MpDHFR. PMID:25014120

  16. IN VITRO INHIBITION OF GLUTATHIONE REDUCTASE BY ARSENOTRI-GLUTATHIONE

    EPA Science Inventory

    Arsenotriglutathione, a product of the reduction of arsenate and the complexation of arsenite by glutathione, is a mixed type inhibitor of the reduction of glutathione disulfide by purified yeast glutathione reductase or the glutathione reductase activity in rabbit erythrocyte ly...

  17. Role of the Tat Transport System in Nitrous Oxide Reductase Translocation and Cytochrome cd1 Biosynthesis in Pseudomonas stutzeri

    PubMed Central

    Heikkilä, Mari P.; Honisch, Ulrike; Wunsch, Patrick; Zumft, Walter G.

    2001-01-01

    By transforming N2O to N2, the multicopper enzyme nitrous oxide reductase provides a periplasmic electron sink for a respiratory chain that is part of denitrification. The signal sequence of the enzyme carries the heptameric twin-arginine consensus motif characteristic of the Tat pathway. We have identified tat genes of Pseudomonas stutzeri and functionally analyzed the unlinked tatC and tatE loci. A tatC mutant retained N2O reductase in the cytoplasm in the unprocessed form and lacking the metal cofactors. This is contrary to viewing the Tat system as specific only for fully assembled proteins. A C618V exchange in the electron transfer center CuA rendered the enzyme largely incompetent for transport. The location of the mutation in the C-terminal domain of N2O reductase implies that the Tat system acts on a completely synthesized protein and is sensitive to a late structural variation in folding. By generating a tatE mutant and a reductase-overproducing strain, we show a function for TatE in N2O reductase translocation. Further, we have found that the Tat and Sec pathways have to cooperate to produce a functional nitrite reductase system. The cytochrome cd1 nitrite reductase was found in the periplasm of the tatC mutant, suggesting export by the Sec pathway; however, the enzyme lacked the heme D1 macrocycle. The NirD protein as part of a complex required for heme D1 synthesis or processing carries a putative Tat signal peptide. Since NO reduction was also inhibited in the tatC mutant, the Tat protein translocation system is necessary in multiple ways for establishing anaerobic nitrite denitrification. PMID:11160097

  18. Evaluation of nitrate reductase activity in Rhizobium japonicum

    SciTech Connect

    Streeter, J.G.; DeVine, P.J.

    1983-08-01

    Nitrate reductase activity was evaluated by four approaches, using four strains of Rhizobium japonicum and 11 chlorate-resistant mutants of the four strains. It was concluded that in vitro assays with bacteria or bacteroids provide the most simple and reliable assessment of the presence or absence of nitrate reductase. Nitrite reductase activity with methyl viologen and dithionite was found, but the enzyme activity does not confound the assay of nitrate reductase. 18 references

  19. PAI-1 4G-4G and MTHFR 677TT in non-hepatitis C virus/hepatitis B virus-related liver cirrhosis

    PubMed Central

    Pasta, Linda; Pasta, Francesca

    2015-01-01

    AIM: To evaluate the different roles of thrombophilia in patients with and without viral etiology. The thrombophilic genetic factors (THRGFs), PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q and prothrombin 20210A, were studied as risk factors in 1079 patients with liver cirrhosis (LC), enrolled from January 2000 to January 2014. METHODS: All Caucasian LC patients consecutively observed in a fourteen-year period were included; the presence of portal vein thrombosis (PVT) and Budd Chiari syndrome (BCS) was registered. The differences between the proportions of each THRGF with regard to the presence or absence of viral etiology and the frequencies of the THRGF genotypes with those predicted in a population by the Hardy-Weinberg equilibrium were registered. RESULTS: Four hundred and seventeen/one thousand and seventy-six patients (38.6%) showed thrombophilia: 217 PAI-1 4G-4G, 176 MTHFR C677TT, 71 V Leiden factor and 41 prothrombin G20210 A, 84 with more than 1 THRGF; 350 presented with no viral liver cirrhosis (NVLC) and 729 with, called viral liver cirrhosis (VLC), of whom 56 patients were hepatitis C virus + hepatitis B virus. PAI-1 4G-4G, MTHFR C677TT, the presence of at least one TRHGF and the presence of > 1 THRGF, were statistically more frequent in patients with NVLC vs patients with VLC: All χ2 > 3.85 and P < 0.05. Patients with PVT and/or BCS with at least one TRHGF were 189/352 (53.7%). The Hardy-Weinberg of PAI-1 and MTHFR 677 genotypes deviated from that expected from a population in equilibrium in patients with NVLC (respectively χ2 = 39.3; P < 0.000 and χ2 = 27.94; P < 0.05), whereas the equilibrium was respected in VLC. CONCLUSION: MTHFR 677TT was nearly twofold and PAI-1 4G-4G more than threefold more frequently found in NVLC vs patients with VLC; the Hardy-Weinberg equilibrium of these two polymorphisms confirms this data in NVLC. We suggest that PAI-1 4G-4G and MTHFR 677TT could be considered as factors of fibrosis and thrombosis mechanisms, increasing

  20. Correlation with Platelet Parameters and Genetic Markers of Thrombophilia Panel (Factor II g.20210G>A, Factor V Leiden, MTHFR (C677T, A1298C), PAI-1, β-Fibrinogen, Factor XIIIA (V34L), Glycoprotein IIIa (L33P)) in Ischemic Strokes.

    PubMed

    Tasdemir, Sener; Erdem, Haktan Bagis; Sahin, Ibrahim; Ozel, Lutfi; Ozdemir, Gokhan; Eroz, Recep; Tatar, Abdulgani

    2016-06-01

    An important type of arterial thrombosis, ischemic stroke is associated with increased mortality risk, severe disability and life quality impairment. In this study, we analyzed mean platelet volume, platelet count values and genetic thrombophilia markers of patients who have ischemic stroke history and searched the relationship with genetic predisposition of ischemic strokes and platelet parameters. A retrospective, clinical trial was performed by reviewing the ischemic stroke history (except cryptogenic events) of 599 patients and 100 controls. The results of the genetic thrombophilia panel were used to classify the study group and control group into low and high risk for thrombophilia groups. The high-risk group included patients homozygous/heterozygous for Factor II g.20210G>A or Factor V Leiden mutations with/without any other polymorphism. The low-risk group included patients heterozygous or homozygous for MTHFR (C677T, A1298C), PAI-1, β-fibrinogen, Factor XIIIA (V34L) and glycoprotein IIIa (L33P) polymorphisms or negative in terms of both mutations and polymorphisms. The results of study showed us that high-risk group mutations are important risk factors for ischemic stroke but low-risk group polymorphisms are not significant. According to platelet parameters, although there was a significant difference between MPV and PLT values of ischemic stroke and control group, thrombophilia mutations and polymorphisms have not a significant effect on MPV and PLT values in ischemic stroke patients. PMID:26951304

  1. FACKEL is a sterol C-14 reductase required for organized cell division and expansion in Arabidopsis embryogenesis

    PubMed Central

    Schrick, Kathrin; Mayer, Ulrike; Horrichs, Andrea; Kuhnt, Christine; Bellini, Catherine; Dangl, Jeff; Schmidt, Jürgen; Jürgens, Gerd

    2000-01-01

    In flowering plants, the developing embryo consists of growing populations of cells whose fates are determined in a position-dependent manner to form the adult organism. Mutations in the FACKEL (FK) gene affect body organization of the Arabidopsis seedling. We report that FK is required for cell division and expansion and is involved in proper organization of the embryo. We isolated FK by positional cloning. Expression analysis in embryos revealed that FK mRNA becomes localized to meristematic zones. FK encodes a predicted integral membrane protein related to the vertebrate lamin B receptor and sterol reductases across species, including yeast sterol C-14 reductase ERG24. We provide functional evidence that FK encodes a sterol C-14 reductase by complementation of erg24. GC/MS analysis confirmed that fk mutations lead to accumulation of intermediates in the biosynthetic pathway preceding the C-14 reductase step. Although fk represents a sterol biosynthetic mutant, the phenotype was not rescued by feeding with brassinosteroids (BRs), the only plant sterol signaling molecules known so far. We propose that synthesis of sterol signals in addition to BRs is important in mediating regulated cell growth and organization during embryonic development. Our results indicate a novel role for sterols in the embryogenesis of plants. PMID:10859166

  2. Short Report: Detection of the Dihydrofolate Reductase–164L Mutation in Plasmodium falciparum Infections from Malawi by Heteroduplex Tracking Assay

    PubMed Central

    Juliano, Jonathan J.; Trottman, Paul; Mwapasa, Victor; Meshnick, Steven R.

    2008-01-01

    Standard polymerase chain reaction methods often cannot detect drug-resistance mutations in Plasmodium falciparum infections if the mutation is present in ≤ 20% of the parasites. A heteroduplex tracking assay was developed that can detect dihydrofolate reductase 164-L mutations in variants representing 1% of the parasites in an individual host. Using this assay, we confirmed the presence of the mutation in P. falciparum infections in Malawi. PMID:18541765

  3. Bacteriophage T4 Virion Baseplate Thymidylate Synthetase and Dihydrofolate Reductase

    PubMed Central

    Kozloff, L. M.; Lute, M.; Crosby, L. K.

    1977-01-01

    Additional evidence is presented that both the phage T4D-induced thymidylate synthetase (gp td) and the T4D-induced dihydrofolate reductase (gp frd) are baseplate structural components. With regard to phage td it has been found that: (i) low levels of thymidylate synthetase activity were present in highly purified preparations of T4D ghost particles produced after infection with td+, whereas particles produced after infection with td− had no measurable enzymatic activity; (ii) a mutation of the T4D td gene from tdts to td+ simultaneously produced a heat-stable thymidylate synthetase enzyme and heat-stable phage particles (it should be noted that the phage baseplate structure determines heat lability); (iii) a recombinant of two T4D mutants constructed containing both tdts and frdts genes produced particles whose physical properties indicate that these two molecules physically interact in the baseplate. With regard to phage frd it has been found that two spontaneous revertants each of two different T4D frdts mutants to frd+ not only produced altered dihydrofolate reductases but also formed phage particles with heat sensitivities different from their parents. Properties of T4D particles produced after infection with parental T4D mutants presumed to have a deletion of the td gene and/or the frd gene indicate that these particles still retain some characteristics associated with the presence of both the td and the frd molecules. Furthermore, the particles produced by the deletion mutants have been found to be physically different from the parent particles. PMID:894793

  4. Post-translational Regulation of Nitrate Reductase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrate reductase (NR) catalyzes the reduction of nitrate to nitrite, which is the first step in the nitrate assimilation pathway, but can also reduce nitrite to nitric oxide (NO), an important signaling molecule that is thought to mediate a wide array of of developmental and physiological processes...

  5. Promiscuity and diversity in 3-ketosteroid reductases.

    PubMed

    Penning, Trevor M; Chen, Mo; Jin, Yi

    2015-07-01

    Many steroid hormones contain a Δ(4)-3-ketosteroid functionality that undergoes sequential reduction by 5α- or 5β- steroid reductases to produce 5α- or 5β-dihydrosteroids; and a subsequent 3-keto-reduction to produce a series of isomeric tetrahydrosteroids. Apart from steroid 5α-reductase all the remaining enzymes involved in the two step reduction process in humans belong to the aldo-keto reductase (AKR) superfamily. The enzymes involved in 3-ketosteroid reduction are AKR1C1-AKR1C4. These enzymes are promiscuous and also catalyze 20-keto- and 17-keto-steroid reduction. Interest in these reactions exist since they regulate steroid hormone metabolism in the liver, and in steroid target tissues, they may regulate steroid hormone receptor occupancy. In addition many of the dihydrosteroids are not biologically inert. The same enzymes are also involved in the metabolism of synthetic steroids e.g., hormone replacement therapeutics, contraceptive agents and inhaled glucocorticoids, and may regulate drug efficacy at their cognate receptors. This article reviews these reactions and the structural basis for substrate diversity in AKR1C1-AKR1C4, ketosteroid reductases. This article is part of a Special Issue entitled 'Steroid/Sterol signaling'. PMID:25500069

  6. Promiscuity and diversity in 3-ketosteroid reductases

    PubMed Central

    Penning, Trevor M.; Chen, Mo; Jin, Yi

    2014-01-01

    Many steroid hormones contain a Δ4-3-ketosteroid functionality that undergoes sequential reduction by 5α- or 5β- steroid reductases to produce 5α- or 5β-dihydrosteroids; and a subsequent 3-keto-reduction to produce a series of isomeric tetrahydrosteroids. Apart from steroid 5α-reductase all the remaining enzymes involved in the two step reduction process in humans belong to the aldo-keto reductase (AKR) superfamily. The enzymes involved in 3-ketosteroid reduction are AKR1C1–AKR1C4. These enzymes are promiscuous and also catalyze 20-keto- and 17-keto-steroid reduction. Interest in these reactions exist since they regulate steroid hormone metabolism in the liver, and in steroid target tissues, they may regulate steroid hormone receptor occupancy. In addition many of the dihydrosteroids are not biologically inert. The same enzymes are also involved in the metabolism of synthetic steroids e.g., hormone replacement therapeutics, contraceptive agents and inhaled glucocorticoids, and may regulate drug efficacy at their cognate receptors. This article reviews these reactions and the structural basis for substrate diversity in AKR1C1–AKR1C4, ketosteroid reductases. This article is part of a Special Issue entitled ‘Steroid/Sterol signaling’. PMID:25500069

  7. Ferrisiderophore reductase activity in Agrobacterium tumefaciens.

    PubMed Central

    Lodge, J S; Gaines, C G; Arceneaux, J E; Byers, B R

    1982-01-01

    Reduction of the iron in ferriagrobactin by the cytoplasmic fraction of Agrobacterium tumefaciens strictly required NaDH as the reductant. Addition of flavin mononucleotide and anaerobic conditions were necessary for the reaction; when added with flavin mononucleotide, magnesium was stimulatory. This ferrisiderophore reductase activity may be a part of the iron assimilation process in A. tumefaciens. PMID:7056702

  8. Functional studies of aldo-keto reductases in Saccharomyces cerevisiae*

    PubMed Central

    Chang, Qing; Griest, Terry A.; Harter, Theresa M.; Petrash, J. Mark

    2007-01-01

    SUMMARY We utilized the budding yeast Saccharomyces cerevisiae as a model to systematically explore physiological roles for yeast and mammalian aldo-keto reductases. Six open reading frames encoding putative aldo-keto reductases were identified when the yeast genome was queried against the sequence for human aldose reductase, the prototypical mammalian aldo-keto reductase. Recombinant proteins produced from five of these yeast open reading frames demonstrated NADPH-dependent reductase activity with a variety of aldehyde and ketone substrates. A triple aldo-keto reductase null mutant strain demonstrated a glucose-dependent heat shock phenotype which could be rescued by ectopic expression of human aldose reductase. Catalytically-inactive mutants of human or yeast aldo-keto reductases failed to effect a rescue of the heat shock phenotype, suggesting that the phenotype results from either an accumulation of one or more unmetabolized aldo-keto reductase substrates or a synthetic deficiency of aldo-keto reductase products generated in response to heat shock stress. These results suggest that multiple aldo-keto reductases fulfill functionally redundant roles in the stress response in yeast. PMID:17140678