Methylenetetrahydrofolate Reductase Single Nucleotide Polymorphisms Research Articles

Relationship between the methylenetetrahydrofolate reductase (MTHFR) rs1801133 SNP and serum homocysteine levels of Zhuang hypertensive patients in the central region of Guangxi

BackgroundThe relationship between the methylenetetrahydrofolate reductase (MTHFR) single nucleotide polymorphism (SNP) and serum homocysteine (Hcy) levels or H-type hypertension in different populations is inconsistent. This study aimed to explore the association between the MTHFR rs1801133 SNP and serum Hcy levels of Zhuang hypertensive patients in the central region of Guangxi.MethodsA total of 606 Zhuang inpatients with essential hypertension were recruited in our hospital from August 2016 to December 2018. The patients were divided into H-type hypertension (Hcy > 10 µmol/L, n = 528) and non–H-type hypertension (Hcy ≤ 10 µmol/L, n = 78) groups. At the same time, an age- and sex-matched group of 379 subjects with normal physical examination in our hospital were selected as the control group. Blood biochemical measurements and genotyping of the MTHFR rs1801133 SNP were performed.ResultsThe prevalence of H-type hypertension was 87.13%. The levels of serum Hcy in patients with hypertension were higher than those in control group (14.20 ± 5.78 μmol/L vs. 11.97 ± 5.39 μmol/L, P < 0.001), especially in patients with H-type hypertension (15.08 ± 5.65 μmol/L, P < 0.001). The frequencies of TT genotype (22.73%) and T allele (46.21%) in patients with H-type hypertension were significantly higher than those in control group (11.35% and 30.47%, respectively) and non–H-type hypertension group (10.26% and 28.85%, respectively; P < 0.001 for all). Multivariate linear regression analysis showed that serum Hcy levels were significantly correlated with creatinine, low-density lipoprotein cholesterol, endogenous creatinine clearance rate, and the MTHFR rs1801133 genotypes in control group, while serum Hcy levels were significantly correlated with creatinine, triglyceride, low-density lipoprotein cholesterol, endogenous creatinine clearance rate, glycosylated hemoglobin, and the MTHFR rs1801133 genotypes in H-type hypertension group (P < 0.05–0.001). Serum Hcy levels in the T allele carriers were higher than those in the T allele noncarriers in both H-type hypertension and control groups.ConclusionsThere was closely related between the MTHFR rs1801133 SNP and serum Hcy levels in Zhuang patients with H-type hypertension in the central region of Guangxi. The MTHFR SNP may be an important reason for the increase of serum Hcy levels in Zhuang patients with H-type hypertension in this region.

Methylenetetrahydrofolate reductase polymorphisms in dental caries-induced pulp inflammation and regeneration of dentine-pulp complex: Future perspectives

Dental caries (DC)-induced pulp infections usually undergo the common endodontic treatment, root canal therapy (RCT). Endodontically treated teeth are devitalized, become brittle and susceptible for re-infection which eventually results in dental loss. These complications arise because the devitalized pulp losses its ability for innate homeostasis, repair and regeneration. Therefore, restoring the vitality, structure and function of the inflamed pulp and compromised dentin have become the focal points in regenerative endodontics. There are very few evidences, so far, that connect methylenetetrahydrofolate reductase single nucleotide polymorphisms (MTHFR-SNPs) and dental disorders. However, the primary consequences of MTHFR-SNPs, in terms of excessive homocysteine and folate deficiency, are well-known contributors to dental diseases. This article identifies the possible mechanisms by which MTHFR-SNP-carriers are susceptible for DC-induced pulp inflammation (PI); and discusses a cell-homing based strategy for in vivo transplantation in an orthotopic model to regenerate the functional dentine-pulp complex which includes dentinogenesis, neurogenesis and vasculogenesis, in the SNP-carriers.

Hyperhomocysteinemia in hypofertile male patients can be alleviated by supplementation with 5MTHF associated with one carbon cycle support.

Homocysteine (Hcy) is a cellular poison, side product of the hydrolysis of S-Adenosyl Homocysteine, produced after the universal methylation effector S -Adenosylmethionine liberates a methyl group to recipient targets. It inhibits the methylation processes and its rising is associated with multiple disease states and ultimately is both a cause and a consequence of oxidative stress, affecting male gametogenesis. We have determined hyper homocysteinhemia (HHcy) levels can be reliably reduced in hypofertile patients in order to decrease/avoid associated epigenetic problems and protect the health of future children, in consideration of the fact that treatment with high doses of folic acid is inappropriate. Homocysteine levels were screened in male patients consulting for long-standing infertility associated with at least three failed Assisted Reproductive Technology (ART) attempts and/or repeat miscarriages. Seventy-seven patients with Hcy levels > 15 µM were treated for three months with a combination of micronutrients including 5- MethylTetraHydroFolate (5-MTHF), the compound downstream to the MTHFR enzyme, to support the one carbon cycle; re-testing was performed at the end of a 3 months treatment period. Genetic status for Methylenetetrahydrofolate Reductase (MTHFR) Single nucleotide polymorphisms (SNPs) 677CT (c.6777C > T) and 1298AC (c.1298A > C) was determined. Micronutrients/5-MTHF were highly efficient in decreasing circulating Hcy, from averages 27.4 to 10.7 µM, with a mean observed decrease of 16.7 µM. The MTHFR SNP 677TT (homozygous form) and combined heterozygous 677CT/1298AC status represent 77.9% of the patients with elevated Hcy. Estimation HHcy should not be overlooked in men suffering infertility of long duration. MTHFR SNPs, especially 677TT, are a major cause of high homocysteinhemia (HHcy). In these hypofertile patients, treatment with micronutrients including 5-MTHF reduces Hcy and even allows spontaneous pregnancies post treatment. This type of therapy should be considered in order to ensure these patients' quality of life and avoid future epigenetic problems in their descendants.

Association of Methylenetetrahydrofolate Reductase Gene Polymorphism in Mothers With Adverse Clinical Outcomes in Neonates.

The presence of polymorphic methylenetetrahydrofolate reductase(MTHFR) in mothers poses a risk for numerous detrimental outcomes in neonates. The present study investigated the association of maternal MTHFR A1298C and C677T single nucleotide polymorphisms (SNPs) with the clinical outcomes in their neonates. The cross-sectional study included 60 mothers and their neonates. Blood samples from mothers were analyzed for MTHFR A1298C and C677T SNP genotyping by real-time polymerase chain reaction. Clinical details of mothers and neonates were documented. Study groups were stratified based on wild, heterozygous, and mutant genotypes for the respective polymorphisms observed in mothers. Multinomial regression was applied for the association, followed by gene model formulation to estimate the impact of the genetic variants on the outcomes. The frequency percentages of mutant CC1298 and TT677 genotypes were 25% and 8.06%, respectively, and the mutant allele frequencies (MAF) were 42.5% and 22.5%. Percentages of adverse outcomes such as intrauterine growth restriction, sepsis, anomalies, and mortality were higher in neonates born to mothers with homozygous mutant genotypes. Maternal C677T MTHFR SNPs revealed a significant association with neonatal anomalies (p = 0.001). The multiplicative risk model depicted OR (95% CI) for CT vs. CC+TT as 3.0 (95% CI: 0.66-13.7), and for TT vs. CT+CC was 15 (95% CI: 2.01-112.12). The C677T SNP in mothers predicted a dominant model for neonatal death (OR (95% CI): 5.84 (0.57-60.03), p = 0.15), whereas the A1298C reported recessive model for 1298CC mothers (OR (95% CI): 11 (1.05-115.5), p = 0.02). Both the genotypes assumed a recessive model for adverse neonatal outcomes: OR (95%CI) for CC vs. AA+ACwas 3.2 (0.79-12.9, p = 0.1), and for TT vs. CC+CT was 5.48 (0.57-175.7, p = 0.2). The risk for sepsis in neonates was nearly six times higher in those born from mothers with homozygous CC1298 and TT677 than in the wild and heterozygous variants. Mothers with C677T and A1298C SNPs are highly susceptible to adverse outcomes in their neonates. Hence, screening the SNPs during the antenatal period can purposefully serve as a better predictive marker, following which proper clinical management could be planned.

MTHFR Gene Polymorphisms in Iraqi Kurdish Rheumatoid Arthritis Patients: Relation to Methotrexate Response and Toxicity

Methotrexate (MTX) is still one of the gold standard treatments for rheumatoid arthritis (RA). It shows diverse outcomes in blood level and clinical response, this was demonstrated by its relation to the genetic polymorphism in the pharmacogenetic study. This study aimed to investigate the role of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms in relation to MTX efficacy and toxicity in Iraqi Kurdish RA patients. Sixty-four RA patients were involved in this study with an average age of 47.78 ±14.08 and female to male ratio of (8.1). Diagnosis and disease activity were confirmed. Blood analyses, including those of laboratory markers of disease activity, were done. The 28 joint disease activity score (DAS28-CRP) was calculated. MTHFR gene polymorphisms were analyzed by real-time polymerase chain reaction. The most frequent genotypes which were identified in RA patients were the CT genotype of the C677T single nucleotide polymorphism (SNP) (51.6%) and the AC genotype of the A1298C SNP (48.4%). Patients with non-response to treatment had high frequencies of genotypes CT and TT (58.0% and 12.0%) of the C677T SNP respectively, as compared to those in the responder group; 28.6% and 0.0%); T-allele was associated with drug non-responding OR=4.17, P value=.0.009, meanwhile; genotypes AC and CC of the A1298C SNP were seen in (54.0% and 16.0%) in non-responder group. Patients with active RA had increased frequencies of CT and TT genotypes of the C677T SNP (60.0% and16.0%) respectively as compared to those who were in remission (26.6% and 0.0%); T-allele was associated with high disease activity; OR = 5.11. No association was found between C677T SNP and A1298C SNP, and MTX level status (P&gt; 0.05). However, the variant alleles (T and C) were associated with the MTX toxic level (OR: 2.05, 95% CI [0.97 – 4.32]) and (OR: 1.99, 95% CI [0.96 – 4.18]) respectively. This study suggests that genetic polymorphisms of MTHFR SNP (C677T and A1298C) are associated with MTX efficacy but not toxicity in RA patients. This may assist the physicians in personalizing RA treatment in Iraqi patients.

T677T Methylenetetrahydrofolate Reductase Single Nucleotide Polymorphisms Increased Prevalence in a Subgroup of Infertile Patients with Endometriosis.

<b><i>Background:</i></b> Approximately 10% (190 million) of women worldwide are affected by endometriosis, ectopic deposits of endometrial tissue that create a major source of pain that affects lifestyle and reproductive function. The pathogenesis of endometriosis is an estrogen-dependent inflammatory process, influenced/catalyzed by oxidative stress and consequently defective methylation, with biochemical features centered around the folate and one-carbon cycles. We aimed to determine whether a link could be found between the two major methylenetetrahydrofolate reductase single nucleotide polymorphisms (MTHFR SNPs), c.677C&gt;T and c.1298A&gt;C, involved in methylation process/epigenetic marking failures, and endometriosis. <b><i>Material and Methods:</i></b> We studied a population of 158 patients in a group of &gt;1500 referred for treatment of infertility. All the patients had experienced &gt;2 failed assisted reproductive technology cycles and/or &gt;2 miscarriages, a classical cohort for investigation in our group. Patients with endometriosis had at least stage 2+ disease confirmed by laparoscopy. <b><i>Results:</i></b> The prevalence of the homozygous c.677C&gt;T isoform is doubled in the endometriosis group, 21.5% versus 10.2% in the non-endometriosis group (<i>p</i> &gt; 0.01). Symmetrically, the percentage of patients in the endometriosis group with the wild type MTHFR significantly decreased by one-half (8.2%-17.2%) in the non-endometriosis group (<i>p</i> &lt; 0.001). <b><i>Conclusion:</i></b> Determination of MTHFR c.677C&gt;T should not be overlooked in patients with harmful endometriosis affecting their fertility. As folates metabolism is impaired in these MTHFR SNPs carrier patients, co-treatment with 5-methyl folate may constitute a successful (co)-treatment modality.

Methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphisms in breast cancer: A Filipino preliminary case-control study

Single nucleotide polymorphisms (SNP) present in folate metabolic enzymes, such as methylenetetrahydrofolate reductase (MTHFR), affect DNA synthesis and methylation processes that can lead to cancer development. Several studies suggest that MTHFR SNP is associated with breast cancer risk, particularly among Asian populations. Thus, this study determined the association of MTHFR 677C>T SNP with breast cancer risk in selected Filipino population. DNA samples from breast cancer cases (n = 100) and clinically healthy controls (n = 100) were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The differences in MTHFR genotype and allele frequencies were evaluated by computing for the odds ratio (OR) with a 95 % confidence interval (CI). The CT genotype (OR: 0.775, 95 % CI: 0.35–1.71, p = 0.53), T allele (OR: 0.703, 95 % CI: 0.34–1.48, p = 0.35), and presence of at least one T allele (ORCT+TT: 0.729, 95 % CI: 0.33–1.60, p = 0.43) were not associated with breast cancer risk. Based on the SNP interaction with other risk factors, no significant difference (p > 0.05) was observed for the tumor characteristics, menarche age, and menopause age. Interestingly, a decreased risk (OR: 0.342, 95 % CI: 0.14–0.84, p = 0.019) was observed for the CC genotype in individuals who consumed dietary fibers. Meanwhile, there was an increased risk for passive smokers with the CC genotype (OR: 6.31, 95 % CI: 2.68–14.9, p < 0.001). Overall, the MTHFR 677C>T was not significantly associated with breast cancer risk in a selected Filipino population. Since this study involved a relatively small number of participants, increasing the number of samples is recommended for a more conclusive test of association of MTHFR 677C>T with breast cancer risk in Filipinos.

MTHFR SNPs (Methyl Tetrahydrofolate Reductase, Single Nucleotide Polymorphisms) C677T and A1298C Prevalence and Serum Homocysteine Levels in >2100 Hypofertile Caucasian Male Patients

Methylation is a crucially important ubiquitous biochemical process, which covalently adds methyl groups to a variety of molecular targets. It is the key regulatory process that determines the acquisition of imprinting and epigenetic marks during gametogenesis. Methylation processes are dependent upon two metabolic cycles, the folates and the one-carbon cycles. The activity of these two cycles is compromised by single nucleotide polymorphisms (SNPs) in the gene encoding the Methylenetetrahydrofolate reductase (MTHFR) enzyme. These SNPs affect spermatogenesis and oocyte maturation, creating cytologic/chromosomal anomalies. The two main MTHFR SNP variants C677T (c.6777C>T) and A1298C (c.1298A>C) together with serum homocysteine levels were tested in men with >3 years’ duration of infertility who had failed several ART attempts with the same partner. These patients are often classified as having “idiopathic infertility”. We observed that the genetic status with highest prevalence in this group is the heterozygous C677T, followed by the combined heterozygous C677T/A1298C, and then A1298C; these three variants represent 65% of our population. Only 13.1% of the patients tested are wild type (WT), C677C/A1298A). The homozygous 677TT and the combined heterozygote 677CT/1298AC groups have the highest percentage of patients with an elevated circulating homocysteine level of >15 µMolar (57.8% and 18.8%, respectively, which is highly significant for both). Elevated homocysteine is known to be detrimental to spermatogenesis, and the population with this parameter is not marginal. In conclusion, determination of these two SNPs and serum homocysteine should not be overlooked for patients with severe infertility of long duration, including those with repeated miscarriages. Patients must also be informed about pleiotropic medical implications relevant to their own health, as well as to the health of future children.

Metabolic Analysis of Methylenetetrahydrofolate Reductase Single Nucleotide Polymorphisms (MTHFR 677C

Neural tube defects (NTDs)are among the most prevalent and debilitating birth defects with their causes are still unknown, despite mounting evidence that genetic and/or environmental factors may play a role. We aimed to analyze two single nucleotide polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene, serum folate and vitamin B12 status among a cohort of Egyptian children with NTDs and their mothers. A case-control study has been conducted on 50 Egyptian children with various types of NTDs and their mothers. They were comparable with 50 unrelated healthy, age and sex matched children and their mothers (50) selected as controls. Pediatric and neurosurgical assessments were performed to the included cases. Serum folate and vitamin B12 were measured using ELISA kits. MTHFR 677C<T (rs1801133) and MTHFR1298A<C (rs1801131) were analyzed by restriction fragment length polymorphism using polymerase chain reaction. Lumbosacral meningomyelocele was the most frequent NTDs (50%). Significantly lower serum folate and vitamin B12 among cases and case mothers compared to the control and control mothers (p<0.05 for all). Significantly higher frequencies of both heterozygous mutant (CT) and homozygous mutant (TT) genotypes, and mutant T allele of MTHFR 677C<T among case mothers compared to control mothers (p<0.05 for all), with lack of significant differences of this SNP between pediatric groups. Mutant homozygous (AA) genotype and mutant A allele of MTHFR 1298A<C among control mothers were significantly frequent compared to case mothers (p<0.05 for both), with OR 6.081 and 7.071, [95%CI were 3.071-11.287 and 3.296-15.172, respectively]. Significantly frequent wild homozygous (CC) genotype and normal C allele of MTHFR 1298A<C among children with NTDs compared to the controls (p<0.05 for both), with OR 0.231 and 0.754, [95%CI were 0.095-0.561and 0.432-1.317, respectively].Low serum folate and B12 are frequently common among children with NTDs and their mothers. MTHFR 677C<T in mothers could be considered as genetic risk factors for development of NTDs in their children, while MTHFR1298A<C could be protective genetic factor against NTDs development.

The Risk Stratification of Coronary Vascular Disease as Linked to Homocysteine, its Modulating Genes, Genetic Polymorphisms, Conventional Predictors, and with Antihypertensive Medicaments

Cardiovascular disease (CVD) have multifactorial nature, and owing to their disparate etiological roots, it is difficult to ascertain exact determinants of CVD. In the current study, primary objective was to determine association of single nucleotide polymorphisms (SNP) in folate pathway genes, homocysteine, antihypertensive medication, and of known risk factors in relation to CVD outcomes. The participants numbered 477 (controls, n = 201, ischemic heart disease patients, n = 95, and myocardial infarction cases, n = 181, respectively). SNPs that were queried for homocysteine pathway genes included, "methylene tetrahydrofolate reductase (MTHFR)" gene SNPs rs1801133 and rs1801131, "methyltransferase (MTR)" SNP rs1805087, "paraoxonase 1 (PON1)" SNP rs662, and angiotensin-converting enzyme (ACE) gene polymorphisms rs4646994. Medication data were collected through questionnaire, and serum-based parameters were analyzed through commercial kits. The analysis of variance and multiple comparison scrutiny revealed that age, gender, family history, cholesterol, creatinine, triglyceride, high density lipoproteins (HDL), homocysteine, beta-blocker, ACE inhibitors, MTHFR and PON1 SNPs related to coronary artery disease (CAD). On regression, rs662 SNPs and C-reactive protein had nonsignificant odds ratio, whereas age, gender, creatinine, and HDL were nonsignificant. Family history, cholesterol, homocysteine, beta blocker, and ACE inhibitors, homocysteine, rs1801133 and rs1801131 SNP maintained significance/significant odds for CAD. The current study indicates an intricate relationship between genetic variants, traditional factors, and drug usage in etiogenesis of arterial disease. Differences in SNPs, their modulated effects in consensus with medicinal usage may be related to ailment outcomes affecting coronary vasculature.

The Connotation of Variances in the Risk Predictors, Medications, Homocysteine, and Homocysteine Pathway Gene Polymorphisms with CVA/Stroke.

Cerebrovascular accidents (CVAs) are vascular multifactorial, multigenic ailments with intricate genetic, environmental risk influences. The present study aimed to establish affiliation of CVAs/stroke with blood parameters, differences in prescribed drugs consumption, and with differences in homocysteine pathway genes polymorphisms. The participants in study included controls n = 251, transient ischemic attack (TIA) patients n = 16, and stroke cases n = 122, respectively, (total participants, n = 389). The analyzed single nucleotide polymorphisms (SNPs) included C677T(rs1801133), A1298C(rs1801131) of methylene tetrahydrofolate reductase ( MTHFR ), A2756G(rs1805087) of methyl tetrahydrofolate homocysteine methyltransferase/methionine synthase ( MS ), and the A192G(rs662) of paraoxonase 1( PON1 ) genes, all validated by tetra-primer allele refractory mutation system polymerase chain reaction (T-ARMS-PCR). The insertion deletion (I/D; rs4646994) polymorphism in angiotensin converting enzyme ( ACE ) gene was analyzed using routine PCR. All studied traits were scrutinized through analysis of variance (ANOVA), and later through regression analysis. Through ANOVA and multiple comparison, there was association of CVA with serum homocysteine, cholesterol, and with diastolic blood pressure readings. When data was subjected to regression, serum homocysteine and diastolic blood pressure (significant through ANOVA), as well as two additional traits, high-density lipoproteins (HDL), and rs1801133 MTHFR SNP sustained statistical significance and noteworthy odds in relation to CVA and stroke. The ailments affecting cerebral vasculature are mutifactorial, whereby genes, proteins, and environmental cues all exert cumulative effects enhancing CVA risk. The current study emphasizes that SNPs and variation in circulating biomarkers can be used for screening purposes and for reviewing their effects in stroke/CVA-linked risk progression.

Association between MTHFR C677T/A1298C and susceptibility to autism spectrum disorders: a meta-analysis

BackgroundAutism spectrum disorder (ASD) is becoming increasingly prevalent of late. Methylenetetrahydrofolate reductase (MTHFR) has a significant role in folate metabolism. Owing to the inconsistencies and inconclusiveness on the association between MTHFR single nucleotide polymorphism (SNP) and ASD susceptibilities, a meta-analysis was conducted to settle the inconsistencies.MethodsFor this meta-analysis, a total of 15 manuscripts published up to January 26, 2020, were selected from PubMed, Google Scholar, Medline, WangFang, and CNKI databases using search terms “MTHFR” OR “methylenetetrahydrofolate reductase” AND “ASD” OR “Autism Spectrum Disorders” OR “Autism” AND “polymorphism” OR “susceptibility” OR “C677T” OR “A1298C”.ResultsThe findings of the meta-analysis indicated that MTHFR C677T polymorphism is remarkably associated with ASD in the five genetic models, viz., allelic, dominant, recessive, heterozygote, and homozygote. However, the MTHFR A1298C polymorphism was not found to be significantly related to ASD in the five genetic models. Subgroup analyses revealed significant associations of ASD with the MTHFR (C677T and A1298C) polymorphism. Sensitivity analysis showed that this meta-analysis was stable and reliable. No publication bias was identified in the associations between MTHFRC677T polymorphisms and ASD in the five genetic models, except for the one with regard to the associations between MTHFRA1298C polymorphisms and ASD in the five genetic models.ConclusionThis meta-analysis showed that MTHFR C677T polymorphism is a susceptibility factor for ASD, and MTHFR A1298C polymorphism is not associated with ASD susceptibility.

Association between methylene tetrahydrofolate reductase polymorphisms and risk of ischemic stroke

Background: The methylene tetrahydrofolate reductase (MTHFR) is a folate-dependent enzyme which catalyzes the conversion of homocysteine to methionine. Two single nucleotide polymorphisms (SNPs) within this gene namely rs1801133 (C677T) and rs1801131 (A1298C) have been associated with elevated risk of ischemic stroke and total serum homocysteine in some populations.Aim: To assess associations between MTHFR SNPs and risk of ischemic stroke in Iranian population.Methods: In the current case-control study, we genotyped rs1801133 and rs1801131 SNPs in 318 Iranian patients with history of ischemic stroke and 400 age- and sex-matched controls using tetra-primer amplification refractory mutation system-polymerase chain reaction method.Results: The rs1801133 was significantly associated with risk of stroke in recessive model (OR (95% CI) = 1.89 (1.12–3.20), p = 0.03). The CT haplotype (rs1801131 and rs1801133, respectively) was significantly over-represented in patients compared with controls (OR (95% CI) = 1.71 (0.25–2.32), p = 0.002).Conclusion: Consequently, our data demonstrate contribution of MTHFR variants in risk of ischemic stroke in Iranian population.

Single-nucleotide polymorphisms of methylenetetrahydrofolate reductase gene in a South Indian cohort with nonsyndromic cleft lip with or without palate.

Objective:Clefts of the lip, with or without cleft palate and cleft palate only, collectively called as orofacial clefts (OFCs) are one of the most common congenital malformations with varying degrees of penetrance and phenotype expressions. The aim of this study was to investigate the association between methylenetetrahydrofolate reductase (MTHFR) cytosine-to-thymine (c. 677 C>T), adenine-to-cytosine (c.1298 A>C) single- nucleotide polymorphisms (SNPs) and South Indian patients with the nonsyndromic cleft lip with or without palate (NSCL ± P).Methods:A cohort consisting of 25 cases of NSCL ± P and 18 controls from a South Indian cohort were included in this case–control study. Genetic analysis of c.677C>T and c.1298A C polymorphisms in the MTHFR gene was carried out using Sanger sequencing and analyzed from chromatogram profiles. Data interpretation was done using statistical software MedCalc Statistical Software version 16.2 and the Statistical Package for the Social Sciences (SPSS version 22.0).Results:DNA sequence analysis of the MTHFR gene revealed c. 677C>T and c. 1298A>C polymorphisms in 16% and 76% of NSCL ± P cases, respectively. Heterozygous variant in MTHFR c. 1298A>C polymorphism was found to be a significant risk factor (P = 0.0164) for NSCL ± P in South Indian ethnic population. c.677C>T polymorphism, in particular, was apparently dormant overall in the study population. These results offer certain novelty in terms of the distinctive pattern in SNPs of genotypes observed in the study.Conclusion:NSCL ± P is one of the most common and challenging congenital malformations with complex etiological basis. Common risk factors such as MTHFR SNPs, namely c.677C>T and c.1298A>C, are subjected to variations in terms of ethnic group, geographic region and micro/macro-environmental factors. Overall, our study has explored part of South Indian ethnic population and revealed a different and unique distribution of mutations in this sample population.

The Impact of Methylenetetrahydrofolate Reductase (MTHFR) Sperm Methylation and Variants on Semen Parameters and the Chance of Recurrent Pregnancy Loss in the Couple.

Recurrent pregnancy loss (RPL) defined as three or more consecutive spontaneous miscarriages before the 20th week of gestation is caused by different factors including genetic and epigenetic background. However the involvement of paternal background on RPL is an interesting novel argument, which is not well studied. The main focus of the present study was to investigate for the association of paternal methylenetetrahydrofolate reductase (MTHFR) epigenotypes with sperm parameters and RPL. Moreover, the frequency of two of MTHFR Single Nucleotide Polymorphisms (SNPs) in males was assessed. This is a case-control study. Methylation Specific PCR (MSP) was used to evaluate the methylation status of MTHFR promoter on sperm DNA of 25 male partners of RPL and 25 male partners of non-RPL couples. PCR-RFLP method was used to analyze 1,298 A>C (rs1801131) and 677 C>T (rs1801133) polymorphisms. No significant difference was observed in frequency of methylated MTHFR epigenotype between RPL and non-RPL males. Furthermore, methylated MTHFR epigenotype was more frequent (but not statistically significant) among men with abnormal sperm parameters compared to normal-sperm men. Among studied polymorphisms, only the mutated allele of C677T showed statistically higher prevalence among RPL males. Although our results do not establish any connection between MTHFR epigenotypes and RPL they do highlight the impact of C677T in the pathology.

Prediction of severe toxicity in adult patients under treatment with 5-fluorouracil: a prospective cohort study.

5-Fluorouracil (5-FU) has long been used for the treatment of gastrointestinal tumors harboring interindividual variability in both the pharmacokinetic and the pharmacogenetic profiles, which in turn may lead to life-threatening toxicities. We carried out a prospective cohort study of adult patients initiating treatment with 5-FU between 2013 and 2015. Primary exposures of interest were the methylenetetrahydrofolate reductase single nucleotide polymorphism in exons 4 and 7 and 5'-untranslated region-thymidylate synthase VNTR genotypes, in addition to baseline clinical and demographic variables. The primary outcome was the time to the occurrence of severe toxicity. We used a Cox regression model to evaluate patients' survival and toxicity experience and its association with baseline characteristics and a priori determined genetic polymorphisms. A total of 197 patients were included, 40.1% developed severe toxicity during follow-up. Variables that were significantly associated with developing severe toxicity were the European Organization for Research and Treatment of Cancer functional score [hazard ratio (HR): 0.98; 95% confidence interval (CI): 0.97-0.99]; type of tumor [anus (HR: 2.50; 95% CI: 1.07-5.82), head and neck/esophagus/stomach (HR: 2.95; 95% CI: 1.64-5.33)] and 5-FU continuous infusion regimens over 4-5 days (HR: 9.35; 95% CI: 2.68-32.59). We found a significant association between baseline functional status, type of tumor and continuous infusion regimens and the occurrence of severe toxicity during the follow-up of patients receiving 5-FU. No association was found with the genotypic variants evaluated. Future validation and modeling of an everyday easy-to-use score to predict toxicity among these subgroup of patients remains warranted.

Methylenetetrahydrofolate Reductase Polymorphisms and Risk of Recurrent Pregnancy Loss: a Case-Control Study.

The balance between coagulation and fibrinolysis is an essential part in early pregnancy. Mutations in methylenetetrahydrofolate reductase (MTHFR) gene lead to decreased activity of the enzyme and hyperhomocysteinemia, which then induces platelet aggregation by promoting endothelial oxidative damage, possibly resulting in adverse effect on maintenance of pregnancy. We investigated the role of MTHFR single nucleotide polymorphisms (SNPs), C677T and A1298C, in Korean patients with recurrent pregnancy loss (RPL). We conducted a prospective case-control study in the Korean population. Subjects included 302 women with 2 or more consecutive, unexplained, spontaneous miscarriages before 20 weeks of gestation and 315 control women without a history of recurrent miscarriages. The genotyping for C677T and A1298C polymorphisms was performed using the TaqMan assay. Continuous variables were compared using Student's t-test, and χ2 test was used to evaluate differences in the genotype distributions between the RPL and the controls. The genotype distribution of both polymorphisms in the RPL group did not differ from those of the controls. For further analysis, if RPL patients were divided according to the numbers of pregnancy losses (≥ 2 and ≥ 3) neither group was significantly different compared with controls. MTHFR gene C677T and A1298C polymorphisms are not associated with idiopathic RPL in Korean women, suggesting that those may not be susceptible allelic variants or be deficient to cause RPL.

The Frequency of Some Thrombophilic Mutations in Eastern Turkey.

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. 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. 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. 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.

P36. Identifying a novel link between preeclampsia and chronic hypertension in the MTHFR-gene using the population based Norwegian HUNT Study

Introduction Preeclampsia is a complex genetic disease of pregnancy including new-onset hypertension with proteinuria. Research has demonstrated that after preeclamptic pregnancies these women are at increased risk for cardiovascular diseases (CVD) later in life. Although the link between the diseases is currently obscure, the pathophysiology of both conditions incorporates dysregulated inflammation. Objectives In this study we aimed to identify genetic components of the shared pathophysiology of preeclampsia and the CVD risk factor chronic hypertension. Methods A cohort from the Norwegian HUNT Study was selected, containing 1006 women with a history of preeclampsia and 816 women with non-preeclamptic pregnancies. From significant findings in existing genome-wide association studies on either chronic hypertension or inflammation we identified 122 candidate single nucleotide polymorphisms (SNPs). These SNPs were genotyped on the Sequenom MassArray System and tested for association with preeclampsia and chronic hypertension in the selected HUNT Study cohort in a multiple logistic regression model in PLINK software. Results After Bonferroni-adjustment the minor allele of the intronic SNP rs17367504 in the methylenetetrahydrofolate reductase (MTHFR) gene was significantly associated with a protective effect on preeclampsia (minor allele frequency 13%, OR 0.65, CI 95% 0.53–0.80, p =3.52×10 −5 ). This SNP did not demonstrate a significant association with chronic hypertension in our data set. Conclusion Our study demonstrates a genetic link between PE and CVD. The MTHFR enzyme has been linked repeatedly to the regulation of folic acid while the minor allele of the MTHFR SNP rs17367504 is known to be associated with a protective effect on chronic hypertension in CVD-based cohorts. We have identified a novel effect of the MTHFR SNP rs17367504, finding this SNP to be associated with reduced risk of preeclampsia.

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

PurposeCongenital 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.Methods138 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.ResultsThere 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).ConclusionsBesides 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.