Assessment of the Particularities of Thrombophilia in the Management of Pregnant Women in the Western Part of Romania.

Background and objectives: Thrombophilia in pregnant women is a condition whose incidence is constantly increasing worldwide, and, under these conditions, the development of preventive procedures is becoming essential. In this study, we aimed to evaluate thrombophilia in pregnant women in the western part of Romania and to establish anthropometric characteristics, socioeconomic features, and genetic and risk factors. Material and Methods: 178 pregnant women were divided into three study groups, according to the type of thrombophilia, aiming to carry out the genetic profile and the acquired one. Anthropometric measures and biological tests were performed. Results: The mixed type of thrombophilia predominates. The particularities of pregnant women diagnosed with thrombophilia are higher age, living in an urban environment, with normal BMI, approximately 36 weeks of gestational period, and having at least one miscarriage. Regarding the most frequent thrombophilic genetic markers, we obtained the MTFHR gene mutation C677T and A1298C, followed by the PAI-1 4G/5G gene mutation. Smoking represents an aggravating factor in the evolution of this pathology, manifested through the increase of D-dimers and the decrease in antithrombin values, simultaneously with the increase in therapeutic need. Conclusions: The predominance of MTHFR and PAI-1 4G/5G gene polymorphism is a particularity of pregnant women with thrombophilia from the western part of Romania. Smoking is confirmed as an important risk factor in spontaneous abortion.

Yoga: A Natural Solution to Decrease Disease Burden in Children of MTHFR Deficient Parents.

Introduction: MTHFR being a key regulatory enzyme of 1-carbon metabolism pathway serves critical function of generation of SAM, replenishment of glutathione and nucleotide synthesis and finally methylation of the bio molecules. MTHFR gene mutation is a rare au-tosomal recessive inborn error of metabolism and presents with severe hyperhomocysteinemia. MTHFR polymorphisms on the other hand are commonly encountered of which two 677 C>T and 1298 A>C have been most widely studied and reported to increase the vulnerability to neural tube defects, congenital heart disease, various neuropsychiatric disorders like autism spectrum diseases and attention deficit hyperactiv-ity disease, cleft lip/ palate, acute leukaemia, cardiovascular diseases, occlusive vascular disease in children. Methods: We conducted this prospective clinical trial to examine whether yoga practice can up regulate MTHFR gene expression. Considering the prevalence of MTHFR polymorphism, varied spectrum of its implications in disease causation including male infertility, we conducted the trial involving 30 infertile men who underwent 3 weeks of supervised YBLI. Pre and post intervention assessment of the blood and semen sample was done to see the effects. Results: We have found more than fivefold up-regulation in the expression of MTHFR gene with significant reduction of seminal free radical levels after 3 weeks of yoga practice. Interestingly we noticed significantly higher MTHFR polymorphic variants in infertile male patients compared to healthy fertile controls. Conclusion: MTHFR polymorphisms are also independently associated with many paediatric diseases. Diagnosing MTHFR deficiency in children is a challenging job and requires high index of suspicion and continuous vigilance. Yoga based lifestyle may be adopted both by parents planning conception and also by adolescent children who are sufferers of this condition to halt the consequences of mild to moderate MTHFR deficiency.

Assessment of the relationship between methylenetetrahydrofolate reductase polymorphism and acute lymphoblastic leukemia: Evidence from an updated meta-analysis.

OBJECTIVE: The methylenetetrahydrofolate reductase gene C677T polymorphism is closely related to the acute lymphoblastic leukemia. Several case-control studies have investigated this association; however, no conclusions could be drawn. A comprehensive updated meta-analysis is established to explain these contradictions and clarify the overall impact of this variant on the susceptibility to acute lymphoblastic leukemia. METHODS: Electronic searches were conducted to select published studies prior to June 2018. Pooled odds ratios and stratification analysis were performed under different genetic comparison models, age, and ethnicity. RESULTS: Totally, 66 case-control studies including 9619 acute lymphoblastic leukemia cases and 17,396 controls were selected. Our analyses showed that methylenetetrahydrofolate reductase C677T polymorphism was protective mainly in Asian and European countries, under all genetic models and regardless of age, but leukemogenic in mixed population. CONCLUSION: Thus, C677T polymorphism may be a promising acute lymphoblastic leukemia biomarker, but they should be interpreted with caution considering other factors such as folic acid intake, gene-gene and gene-environment interactions.

Machine Learning Models for Genetic Risk Assessment of Infants with Non-syndromic Orofacial Cleft.

The isolated type of orofacial cleft, termed non-syndromic cleft lip with or without cleft palate (NSCL/P), is the second most common birth defect in China, with Asians having the highest incidence in the world. NSCL/P involves multiple genes and complex interactions between genetic and environmental factors, imposing difficulty for the genetic assessment of the unborn fetus carrying multiple NSCL/P-susceptible variants. Although genome-wide association studies (GWAS) have uncovered dozens of single nucleotide polymorphism (SNP) loci in different ethnic populations, the genetic diagnostic effectiveness of these SNPs requires further experimental validation in Chinese populations before a diagnostic panel or a predictive model covering multiple SNPs can be built. In this study, we collected blood samples from control and NSCL/P infants in Han and Uyghur Chinese populations to validate the diagnostic effectiveness of 43 candidate SNPs previously detected using GWAS. We then built predictive models with the validated SNPs using different machine learning algorithms and evaluated their prediction performance. Our results showed that logistic regression had the best performance for risk assessment according to the area under curve. Notably, defective variants in MTHFR and RBP4, two genes involved in folic acid and vitamin A biosynthesis, were found to have high contributions to NSCL/P incidence based on feature importance evaluation with logistic regression. This is consistent with the notion that folic acid and vitamin A are both essential nutritional supplements for pregnant women to reduce the risk of conceiving an NSCL/P baby. Moreover, we observed a lower predictive power in Uyghur than in Han cases, likely due to differences in genetic background between these two ethnic populations. Thus, our study highlights the urgency to generate the HapMap for Uyghur population and perform resequencing-based screening of Uyghur-specific NSCL/P markers.

[Assessment of the sufficiency of Moscow population with folic acid, depending on the combined effect of polymorphism of MTHFR and FTO genes].

The results of assessing the sufficiency of folic acid of the residents of the Moscow region have been presented depending on rs1801133 MTHFR gene polymorphism and rs9939609 FTO gene polymorphism. A total of 326 people were examined, including 74 men and 252 women aged 20 to 65 years. The results of determining the level of folic acid in blood serum showed insufficiency of this vitamin among the population of the Moscow region of the Russian Federation. The expressed vitamin deficit (level <3,0 ng/ml) was detected in 24.2% of the surveyed residents, in 22.8% folic acid level was at the lower bound of the norm (3.0-4.5 ng/ml). The results of genotyping showed a statistically significant association of low folic acid level with rs1801133 MTHFR gene polymorphism in carriers of A allele of rs9939609 FTO gene polymorphism both in the homozygous state (genotype AA) and in the heterozygous (genotype AT) state, OR=4.26; CI (1.40-12.9), p=0.008, as well as with rs9939609 FTO gene polymorphism in carriers of the T allele of rs1801133 MTHFR gene polymorphism both in the homozygous (genotype TT) and heterozygous (CT genotype) state, OR=3.29; CI (1.07-10.1), p=0.03. In carriers of 3 alleles of risk of folic acid deficiency [rs9939609 FTO gene polymorphism and rs1801133 MTHFR gene polymorphism (genotypes CT/AA and TT/AT)] blood serum level of folic acid was below the norm, that indicated folate deficiency in this category of persons.

Medical cost savings in Sakado City and worldwide achieved by preventing disease by folic acid fortification.

The introduction of mandatory fortification of grains with folate in 1998 in the United States resulted in 767 fewer spina bifida cases annually and a cost saving of $603 million per year. However, far more significant medical cost savings result from preventing common diseases, including myocardial infarction, stroke, dementia and osteoporosis. A cost-effectiveness analysis showed a gain of 266 649 quality-adjusted life-years and $3.6 billion saved annually, mainly due to the reduction of cardiac infarction. The recommended folate intake in Japan is 240 µg/day whereas it is 400 µg/day internationally. Our Sakado Folate Project targeted individuals with genetic polymorphism of methylenetetrahydrofolate reductase or with hyperhomocysteinemia. Using, for example, folate-fortified rice, resulted in an increase in serum folate and a decrease in serum homocysteine in the participants, and reduced medical costs were achieved by decreasing myocardial infarction, stroke, dementia and fracture. Due to the small population of Sakado City (approximately 101 000) and small number of births (693) in 2015, a decrease in spina bifida could not be confirmed but there was a significant decrease in the number of very low birthweight infants. The genome notification of subjects was effective in motivating intake of folate, but the increase in serum folate (from 17.4 to 22.5 nmol/L, 129%) was less than that observed following compulsory folic acid fortification of cereals in the USA (from 12.1 to 30.2 nmol/L, 149.6%). Mandatory folic acid fortification is cheap in decreasing medical costs and is thus recommended in Japan.

Genetic impairments in folate enzymes increase dependence on dietary choline for phosphatidylcholine production at the expense of betaine synthesis.

Although single nucleotide polymorphisms (SNPs) in folate-mediated pathways predict susceptibility to choline deficiency during severe choline deprivation, it is unknown if effects persist at recommended intakes. Thus, we used stable isotope liquid chromatography-mass spectrometry (LC-MS) methodology to examine the impact of candidate SNPs on choline metabolism in a long-term, randomized, controlled feeding trial among pregnant, lactating, and nonpregnant (NP) women consuming 480 or 930 mg/d choline (22% as choline-d9, with d9 indicating a deuterated trimethyl amine group) and meeting folate-intake recommendations. Variants impairing folate metabolism, methylenetetrahydrofolate reductase (MTHFR) rs1801133, methionine synthase (MTR) rs1805087 [wild-type (WT)], MTR reductase (MTRR) rs1801394, and methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase-formyltetrahydrofolate synthetase (MTHFD1) rs2236225, influenced choline dynamics, frequently through interactions with reproductive state and choline intake, with fewer genotypic alterations observed among pregnant women. Women with these variants partitioned more dietary choline toward phosphatidylcholine (PC) biosynthesis via the cytidine diphosphate (CDP)-choline pathway at the expense of betaine synthesis even when use of betaine as a methyl donor was increased. Choline intakes of 930 mg/d restored partitioning of dietary choline between betaine and CDP-PC among NP (MTHFR rs1801133 and MTR rs1805087 WT) and lactating (MTHFD1 rs2236225) women with risk genotypes. Overall, our findings indicate that loss-of-function variants in folate-metabolizing enzymes strain cellular PC production, possibly via impaired folate-dependent phosphatidylethanolamine-N-methyltransferase (PEMT)-PC synthesis, and suggest that women with these risk genotypes may benefit from choline intakes exceeding current recommendations.-Ganz, A. B., Shields, K., Fomin, V. G., Lopez, Y. S., Mohan, S., Lovesky, J., Chuang, J. C., Ganti, A., Carrier, B., Yan, J., Taeswuan, S., Cohen, V. V., Swersky, C. C., Stover, J. A., Vitiello, G. A., Malysheva, O. V., Mudrak, E., Caudill, M. A. Genetic impairments in folate enzymes increase dependence on dietary choline for phosphatidylcholine production at the expense of betaine synthesis.

Mitochondrial dysfunction by pro-oxidant vanadium: ex vivo assessment of individual susceptibility.

The aim was to assess the individual susceptibility to mitochondrial impairment induced by ex vivo exposure to vanadium, an airborne pro-oxidant pollutant. In lymphocyte cultures V(IV)-treated of forty-five healthy subjects, we evaluated the mitochondrial transmembrane potential (Δψm) and the H2O2 in comparison to background values. As variables, we included both lifestyle factors and genetic polymorphisms (GSTM1 and GSTT1 variants, and C677T and A1298C variants of methylenetetrahydrofolate reductase MTHFR). H2O2 mitochondrial content increased significantly (P<0.05) after metal exposure while, in comparison to basal Δψm, both depolarisation and hyperpolarisation were recorded. This underlined the mitochondrial dysfunction vanadium-induced that worsens the redox imbalance by endogenous ROS overproduction. Only age was found to contribute significantly to the high inter-individual variability, as assessed by multivariate analysis. In older subjects, the H2O2/Δψm values underline the organelle impairment and, under V-exposure, Δψm values were inversely related to age (R=-0.591; P=0.012).

Quantitative assessment of association between rs1801133 polymorphism and susceptibility to stroke.

Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism, which is essential for DNA synthesis and methylation. Genetic variations in the MTHFR gene seem to contribute to a decreased activity of MTHFR, ultimately confer increased susceptibility to stroke. To assess the association between this polymorphism and stroke risk, we conducted a comprehensive meta-analysis based on 73 eligible studies. A total of 73 studies, including 10,225 cases and 13,800 controls identified between 1999 and 2012, were selected through researching the PubMed, MEDLINE, EMBASE, Cochrane Library, Web of Science, and Chinese Biomedical Chinese National Knowledge Infrastructure and Literature database databases. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the association. Overall, a significant elevated risk of stroke risk was associated with the rs1801133 polymorphism in all genetic models (homozygote model: OR 1.296, 95% CI 1.109-1.514; dominant model: OR 1.179, 95% CI 1.058-1.315; recessive model: OR 1.209, 95% CI 1.063-1.375; allele comparison model: OR 1.154, 95% CI 1.061-1.256). In the stratified analyses, significantly increased stroke risks were indicated among Asians in all genetic models (homozygote model: OR 1.726, 95% CI 1.314-2.267; dominant model: OR 1.535, 95% CI 1.282-1.838; recessive model: OR 1.452, 95% CI 1.160-1.818; allele comparison model: OR 1.403, 95% CI 1.211-1.626).The present meta-analysis suggests that rs1801133 polymorphism contributes to the risk of stroke, of note, in Asian populations.

Genetic and environmental risk assessment and colorectal cancer screening in an average-risk population: a randomized trial.

BACKGROUND: New methods are needed to improve health behaviors, such as adherence to colorectal cancer (CRC) screening. Personalized genetic information to guide medical decisions is increasingly available. Whether such information motivates behavioral change is unknown. OBJECTIVE: To determine whether individualized genetic and environmental risk assessment (GERA) of CRC susceptibility improves adherence to screening in average-risk persons. DESIGN: 2-group, randomized, controlled trial. (ClinicalTrials.gov: NCT0087360). SETTING: 4 medical school-affiliated primary care practices. PARTICIPANTS: 783 participants at average risk for CRC who were not adherent to screening at study entry. INTERVENTION: Participants were randomly assigned to usual care or GERA, which evaluated methylenetetrahydrofolate reductase polymorphisms and serum folate levels. On the basis of prespecified combinations of polymorphisms and serum folate levels, GERA recipients were told that they were at elevated or average risk for CRC. MEASUREMENTS: The primary outcome was CRC screening within 6 months of study entry. RESULTS: Overall screening rates for CRC did not statistically significant differ between the usual care (35.7%) and GERA (33.1%) groups. After adjustment for baseline participant factors, the odds ratio for screening completion for GERA versus usual care was 0.88 (95% CI, 0.64 to 1.22). Within the GERA group, screening rates did not significantly differ between average-risk (38.1%) and elevated-risk (26.9%) participants. Odds ratios for elevated- versus average-risk participants remained nonsignificant after adjustment for covariates (odds ratio, 0.75 [CI, 0.39 to 1.42]). LIMITATION: Only 1 personalized genetic and environmental interaction and 1 health behavior (CRC screening) were assessed. CONCLUSION: In average-risk persons, CRC screening uptake was not positively associated with feedback from a single personalized GERA. Additional studies will be required to evaluate whether other approaches to providing GERA affect screening utilization differently. These findings raise concern about the effectiveness of moderately predictive assessment of genetic risk to promote favorable health care behavior. PRIMARY FUNDING SOURCE: National Institutes of Health.

Quantitative assessment of the association between MTHFR rs1801131 polymorphism and risk of liver cancer.

Methylenetetrahydrofolate reductase (MTHFR) is one of the most important enzymes for folate metabolism which plays a key role in cell metabolism. MTHFR rs1801131 (A1298C) polymorphism can decrease in vitro MTHFR enzyme activity and has been hypothesized to be associated with liver cancer risk. This study aimed to quantify the strength of the association between MTHFR rs1801131 polymorphism and liver cancer risk by performing a meta-analysis. We searched the PubMed and Wanfang databases for studies relating on the association between MTHFR rs1801131 polymorphism and risk of liver cancer. Seven studies with 2,030 cases of liver cancer and 3,096 controls were finally included into the meta-analysis. Meta-analysis of a total of seven studies showed that the homozygote genotype CC of MTHFR rs1801131 polymorphism was significantly associated with decreased risk of liver cancer (for CC versus AA: odds ratio (OR) = 0.65, 95% confidence interval (CI) 0.47-0.89, P = 0.007; for CC versus AA + AC: OR = 0.65, 95% CI 0.48-0.89, P = 0.006). Subgroup by race showed that the homozygote genotype CC of MTHFR rs1801131 polymorphism was significantly associated with decreased risk of liver cancer in Asians (CC versus AA: OR = 0.64, 95% CI 0.46-0.90, P = 0.010; for CC versus AA + AC: OR = 0.63, 95% CI 0.45-0.88, P = 0.007). However, the association in Caucasians was still unclear owing to the limited data available now. Thus, Asian individuals with the homozygote genotype CC of MTHFR rs1801131 polymorphism are significantly associated with decreased risk of liver cancer. The association in Caucasians needs further studies.

Quantitative assessment of the association between MHTFR C677T (rs1801133, Ala222Val) polymorphism and susceptibility to bladder cancer.

BACKGROUND: The association between Methylenetetrahydrofolate reductase (MTHFR) Ala222Val (rs1801133) has been implicated to alter the risk of bladder cancer, but the results are controversial. METHODS: A comprehensive databases of Pubmed, Embase, Web of Science, and the Chinese Biomedical Database (CBM) were searched for case-control studies investigating the association between MTHFR Ala222Val polymorphism and bladder cancer susceptibility. Odds ratios (OR) and 95% confidence intervals (95%CI) were used to assess this possible association. A χ2-based Q-test was used to examine the heterogeneity assumption. Begg's and Egger's test were used to examine the potential publication bias. The leave-one-out sensitivity analysis was conducted to determine whether our assumptions or decisions have a major effect on the results of the review. Statistical analysis was performed with the software program Stata 12.0. RESULTS: A total of 15 independent studies were identified, including 3,570 cases and 3,926 controls. Our analysis suggested that Ala222Val was not associated with bladder cancer risk in overall population under additive model (OR=0.96, 95%CI=0.76-1.21, P=0.731), dominant model (OR=1.00, 95%CI=0.87-1.15, P=0.975), recessive model (OR=0.92, 95%CI=0.79-1.07, P=0.279), and Ala allele versus Val allele (OR=0.96, 95%CI=0.86-1.07, P=0.427). In the subgroup analysis stratified by ethnicity and sources of controls, there were also no significant associations detected among different descent populations, population-based studies and hospital-based studies. CONCLUSION: This meta-analysis showed the evidence that MTHFR Ala222Val polymorphism was not contributed to the development of bladder cancer. VIRTUAL SLIDE: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2117182849994994.

Pharmacogenomic assessment of outcomes of pemetrexed-treated patients with adenocarcinoma of the lung.

PURPOSE: The main objective of this study was to evaluate the association between polymorphisms of the target genes of pemetrexed and clinical outcomes in non-small cell lung cancer (NSCLC) patients treated with pemetrexed. MATERIALS AND METHODS: We assessed polymorphisms at 8 sites in 4 genes [thymidylate synthase (TS), dihydrofolate reductase (DHFR; 1610, 680, 317, intron 1), methylenetetrahydrofolate reductase (MTHFR; 677, 1298), glycinamide ribonucleotide formyl transferase (GARFT; 2255)] associated with pemetrexed metabolism using polymerase chain reaction, gene scanning, and restriction fragment length polymorphism analysis in 90 patients with adenocarcinoma of the lung. RESULTS: Survival was significantly longer with pemetrexed in patients with TS 3RGCC/3RGCC or 3RGGC/3RGGC compared with the other groups (PFS; 5.2 months vs. 3.7 months, p=0.03: OS; 31.8 months vs. 18.5 months, p=0.001). Patients with DHFR 680CC experienced fatigue more frequently (50% vs. 8.6%, p=0.008). Polymorphisms of MTHFR and GARFT were not significantly associated with clinical outcomes of pemetrexed. CONCLUSION: The TS genotype was associated with survival and one DHFR polymorphism was associated with fatigue in NSCLC patients treated with pemetrexed. Further large prospective studies are required to identify other biomarkers that affect patients being treated with pemetrexed for adenocarcinoma of the lung.

Assessment of genetic risk factors for thromboembolic complications in adults with idiopathic nephrotic syndrome.

AIMS: Nephrotic syndrome (NS) may occur with acquired hypercoagulability, however, the fact that it is accompanied by an underlying hereditary thrombophilia, especially combined hereditary thrombophilia would lead to thrombotic events. In this study, we aimed to evaluate the contribution of genetic thrombophilia to development of thrombotic events in adult patients with NS. MATERIAL AND METHODS: Factor V Leiden (FVL), prothrombin, and methylenetetrahydrofolate reductase (MTHFR) gene mutation were studied in 51 newly diagnosed idiopathic NS patients and age- and gender-matched 20 healthy control subjects included in the study. Renal vein Doppler ultrasound was conducted in order to investigate the prevalence of subclinical renal vein thrombosis. RESULTS: Of 51 patients, 6 (11.8%) were established to have thromboembolic (TE) complications at the time of diagnosis (4 symptomatic, 2 subclinical), and no recurring thrombotic episode was observed. Genetic mutation was established in all patients that were found to have TE complications. Acquired hypercoagulability factors were similar in patients without and with TE complication. CONCLUSIONS: The coexistence of inherited thrombophilia in NS may facilitate thromboembolic complications. If the cause of thrombosis cannot be explained by the usual factors attributed to the occurrence of thrombosis in NS, screening for the other factors, such as FVL, MTHFR, and prothrombin gene mutation, may be beneficial.

Quantitative assessment of the associations between MTHFR C677T and A1298C polymorphisms and risk of fractures: a meta-analysis.

Many studies have investigated the associations between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and risk of fractures, but the impact of MTHFR polymorphisms on fractures risk is unclear owing to the obvious inconsistence among those studies. This study aims to quantify the strength of association between MTHFR C677T and A1298C polymorphisms and risk of fractures. We searched the PubMed, Embase and Wanfang databases for articles relating the association between MTHFR C677T and A1298C polymorphisms and risk of fractures in humans. We estimated summary odds ratios (ORs) with their confidence intervals (CIs) to assess the associations. Meta-analyses suggested MTHFR C677T polymorphism was associated with increased risk of any site fractures (for T vs. C, OR = 1.17, 95 % CI 1.03-1.32; for TT vs. CC, OR = 1. 31, 95 % CI 1.11-1.54; for TT vs. CT, OR = 1.22, 95 % CI 1.04-1.43; for TT vs. CT/CC, OR = 1.31, 95 % CI 1.13-1.51). Besides, MTHFR A1298C polymorphism was also associated with increased risk of any site fractures. Subgroup meta-analyses suggested MTHFR C677T polymorphism was associated with increased risk of vertebral fractures under three genetic contrast modes (for TT vs. CC, OR = 1.43, 95 % CI 1.05-1.95; for TT vs. CT, OR = 1.36, 95 % CI 1.01-1.85; for TT vs. CT/CC, OR = 1.50, 95 % CI 1.17-1.91), but there was no association between MTHFR C677T polymorphism and risk of hip fractures and non-vertebral fractures (all P values were more than 0.05). Thus, individuals with homozygote genotype TT of MTHFR C677T have obviously increased risk of vertebral fractures compared those with heterozygote genotype CT or homozygote genotype CC. There is no association between MTHFR C677T polymorphism and risk of hip fractures and non-vertebral fractures.

Quantitative assessment of the association between MTHFR C677T polymorphism and hemorrhagic stroke risk.

Many studies have investigated the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and hemorrhagic stroke, but the impact of MTHFR C677T on hemorrhagic stroke is unclear owing to the obvious inconsistence among those studies. This study aimed to quantify the strength of the association between MTHFR C677T polymorphism and hemorrhagic stroke risk. We searched Pubmed, Emabse and Wangfang databases for studies investigating the association between MTHFR C677T polymorphism and hemorrhagic stroke risk. We estimated the pooled odds ratio (OR) with its 95 % confidence intervals (95 % CI) to assess this possible association. Meta-analysis of included studies suggested that TT genotype was obviously associated with increased risk of hemorrhagic stroke (OR (TT versus CC) = 1.84, 95 % CI 1.45-2.34; OR (TT versus CT) = 1.53, 95 % CI 1.23-1.90; OR (TT versus CT/CC) = 1.64, 95 % CI 1.24-2.00) compared with CC or CT genotypes of MTHFR C677T polymorphism. Subgroup analyses by ethnicity further identified the association above in both Asians and Caucasians. No evidence of publication bias was observed. Thus, meta-analyses of available data suggest an obvious association between MTHFR C677T polymorphism and hemorrhagic stroke risk, and TT genotype contributes to increased risk of hemorrhagic stroke.

Quantitative assessment of the association between MTHFR C677T polymorphism and colorectal cancer risk in East Asians.

A great number of studies regarding the association between MTHFR C677T polymorphism and risk of colorectal cancer (CRC) in East Asians were published, but the results were inconsistent. Thus, a meta-analysis was performed to investigate the association. PubMed, Embase, and CBM databases were searched for eligible publications. Pooled odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were calculated using random or fixed effect models. Finally, 24 case-control studies with a total of 7,230 CRC cases and 9,285 controls were included. Meta-analyses of a total of 24 studies showed there was a statistically significant association between MTHFR C677T polymorphism and decreased CRC risk in East Asians under four genetic models (T versus C, OR = 0.92, 95 % CI 0.85-0.99; TT versus CC, OR = 0.80, 95 % CI 0.69-0.94; TT versus CT/CC, OR = 0.82, 95 % CI 0.71-0.95; TT/CT versus CC, OR = 0.92, 95 % CI 0.86-0.98). The cumulative meta-analyses for the allele contrast (T versus C), homozygote (TT versus CC), dominant (TT/CT versus CC), and recessive (TT versus CT/CC) models all showed a trend of more obvious association as information accumulated by year. Subgroup analyses by country further identified this association in Korea and Japan. This meta-analysis suggests that MTHFR C677T polymorphism is associated with decreased risk of colorectal cancer in East Asians, and MTHFR 677T variant has a protective effect on colorectal cancer.

Quantitative assessment of the effect of MTHFR polymorphisms on the risk of lung carcinoma.

Published studies on the relationships between 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms and lung cancer risk have been conflicting. To derive a more precise estimation of the relationship, a meta-analysis was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between MTHFR C677T and A1298C polymorphisms and lung cancer risk. A total of 15 studies including 10,753 cases and 11,275 controls described C677T genotypes, among which 11 articles totalling 6,161 cases and 7,684 controls described A1298C genotypes, were also involved in this meta-analysis. Overall, no significantly elevated lung cancer risk was found in any genetic models when all studies were pooled. For C677T polymorphism: (TT vs. CC: OR = 1.17, 95% CI = 0.97-1.42; TC vs. CC: OR = 1.06, 95% CI = 0.94-1.20; dominant model: OR = 1.09, 95% CI = 0.96-1.24; and recessive model: OR = 1.08, 95% CI = 0.95-1.24); for A1298C polymorphism: (CC vs. AA: OR = 1.04, 95% CI = 0.91-1.19; AC vs. AA: OR = 0.98, 95% CI = 0.91-1.06; dominant model: OR = 0.99, 95% CI = 0.92-1.06; and recessive model: OR = 1.05, 95% CI = 0.92-1.20). In the subgroup analyses, the results showed that 677T varients could decrease lung cancer risk in female (OR = 0.63, 95% CI = 0.41-0.95, P-value = 0.03, 677CC as reference). No evidence of any associations of MTHFR A1298C polymorphism with lung cancer was found in overall or subgroup analyses. Our meta-analysis supports that the common polymorphisms of C677T and A1298C in MTHFR gene are not susceptibility gene for lung cancer from currently available evidence.

Genome-wide association analysis and fine mapping of NT-proBNP level provide novel insight into the role of the MTHFR-CLCN6-NPPA-NPPB gene cluster.

High blood concentration of the N-terminal cleavage product of the B-type natriuretic peptide (NT-proBNP) is strongly associated with cardiac dysfunction and is increasingly used for heart failure diagnosis. To identify genetic variants associated with NT-proBNP level, we performed a genome-wide association analysis in 1325 individuals from South Tyrol, Italy, and followed up the most significant results in 1746 individuals from two German population-based studies. A genome-wide significant signal in the MTHFR-CLCN6-NPPA-NPPB gene cluster was replicated, after correction for multiple testing (replication one-sided P-value = 8.4 × 10(-10)). A conditional regression analysis of 128 single-nucleotide polymorphisms in the region of interest identified novel variants in the CLCN6 gene as independently associated with NT-proBNP. In this locus, four haplotypes were associated with increased NT-proBNP levels (haplotype-specific combined P-values from 8.3 × 10(-03) to 9.3 × 10(-11)). The observed increase in the NT-proBNP level was proportional to the number of haplotype copies present (i.e. dosage effect), with an increase associated with two copies that varied between 20 and 100 pg/ml across populations. The identification of novel variants in the MTHFR-CLCN6-NPPA-NPPB cluster provides new insights into the biological mechanisms of cardiac dysfunction.