Methylenetetrahydrofolate Reductase C677T Variant Research Articles

The Influence of MTHFR C677T Variants on Neuropathy Risk Among T2dm Patients Receiving Monotherapy Metformin

Neuropathy is the most common microvascular complication among type 2 diabetes mellitus (T2DM). Metformin consumption increases neuropathy risk. The Methylenetetrahydrofolate reductase (MTHFR) enzyme has confirmed its role in neuropathy. Metformin and MTHFR could decrease folate and induce hyperhomoscysteine. One of the common variants of the MTHFR gene is C677T and its located in the exon area. This study aimed to observe the association between variant C677T in the MTHFR gene and the risk of neuropathy among newly diagnosed T2DM patients with naive metformin. This cross-sectional study recruited 103 patients. The neuropathy risk was examined according to medical judgment through Neuropathy Symptom Score (NSS) and Neuropathy Disability Score (NDS) criteria. Genotyping C677T was performed using PCR-RFLP. This study found only one patient has a homozygote mutant, but more than 50% of patients were detected with allele mutants. There were no statistical differences in patient characteristics between CC and CT genotypes (p>0.05). Association between C677T and neuropathy risk was not significant statistically, either in the genotype model (p=0.97), allele model (p=0.82), and dominant model (p=0.91). There was still no significant association after adjusting for several confounding factors. We conclude that C677T in our population did not influence neuropathy risk. More specific criteria and laboratory parameters indicated neuropathy should be examined in the future study.
 Keywords: MTHFR, neuropathy, metformin, and T2DM

Susceptibility to preoperative seizures in glioma patients with elevated homocysteine levels.

Seizures are a common clinical presentation in patients with glioma and substantially impact patients' quality of life. Hyperhomocysteinemia is defined as abnormally high serum levels of homocysteine (Hcy) and is reportedly linked to susceptibility to various nervous system diseases. However, it remains unclear whether and how hyperhomocysteinemia and its associated genetic polymorphisms promote seizures in glioma patients. We retrospectively reviewed all medical data from 127 patients with malignant gliomas, who underwent initial tumor resection by our team between July 2019 and June 2021 and had preoperative measurements of serum Hcy levels. According to whether they had at least one seizure before surgery, they were divided into the seizure and nonseizure groups. We also detected polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and measured intratumoral Hcy levels in these patients. Hyperhomocysteinemia was a susceptibility factor for preoperative seizures in glioma patients according to both univariate analyses (P < 0.001) and multivariate logistic regression analyses (OR 1.239, 95% CI 1.062-1.445, P = 0.007). Patients with the MTHFR C677T variant exhibited elevated serum Hcy levels (P = 0.027) and an increased prevalence of preoperative seizures (P = 0.019). Intratumoral Hcy levels were positively correlated with serum Hcy levels (R = 0.231, P = 0.046) and were elevated in patients with hyperhomocysteinemia (P = 0.031), the MTHFR C677T variant (P = 0.002) and preoperative seizures (P = 0.003). High intratumoral Hcy levels, rather than hyperhomocysteinemia or the MTHFR C677T variant, emerged as an independent risk factor for preoperative seizures (OR 1.303, 95% CI 1.015-1.673, P = 0.038). Furthermore, the effects of hyperhomocysteinemia on epileptic susceptibility were reduced to nonsignificance when intratumoral Hcy was controlled to the same level between groups. Glioma patients with hyperhomocysteinemia and the MTHFR C677T variant were susceptible to preoperative seizures, suggesting their potential as biomarkers for the management of seizures in glioma patients. The elevation of intratumoral Hcy is a possible mechanism underlying this susceptibility.

Association of ACE ID, MTHFR C677T, and MIF-173GC variants with the clinical course of COVID-19 patients

The course of coronavirus disease-2019 (COVID-19) differs from person to person. The relationship between the genetic variations of the host and the course of COVID-19 has been a matter of interest. In this study, we investigated whether Angiotensin-Converting Enzyme (ACE) ID, Methylenetetrahydrofolate Reductase (MTHFR) C677T, and Macrophage Migration Inhibitory Factor (MIF)-173GC variants are risk factors for the clinical course of COVID-19 disease in Turkish patients. One hundred COVID-19 patients were included in the study. The diagnosis of COVID-19 was made using Reverse Transcription Polymerase Chain Reaction (RT-PCR) and Chest Computed Tomography (CT). The patients were evaluated in 3 groups: intensive care, service, and outpatient treatment. ACE ID, MTHFR C677T, and MIF-173GC variants were genotyped by PCR-Restriction Fragment Length Polymorphism (RFLP) methods. When the genotype distribution between the groups was examined, it was found that the frequency of the ACE DD genotype and the D allele was higher in the intensive care group compared to the hospitalized and outpatient groups. MTHFR C677T CT genotype T allele and MIF-173GC, CC genotype C allele were more prevalent in the intensive care group compared to other groups. Patients with PCR-positive results had a higher MTHFR C677T C/C genotype and C allele. In CT-positive patients, the MTHFR C677T CT genotype and the MIF-173GC, G allele were more common. It is predicted that genetic predisposition may contribute to COVID-19 morbidity and mortality. Our results show that ACE ID, MTHFR C677T, and MIF-173GC variants affect the course of COVID-19 disease in the Turkish population.

Methylenetetrahydrofolate Reductase C677T Gene Variant in Relation to Body Mass Index and Folate Concentration in a Polish Population.

Methylenetetrahydrofolate reductase (MTHFR) is an enzyme responsible for producing an active form of folate. The MTHFR T677T genotype may have adverse health effects associated with weight gain and a reduction in folate availability. In this study, we examined the influence of the MTHFR C677T variant on BMI and determined its role as a risk factor for obesity. We also assessed the relationships between the MTHFR C677T genotype and folate and vitamin B12 concentrations in subjects before and after radical weight loss. The study group consisted of 1712 Caucasian adults of Polish nationality with a wide range of body mass indexes (BMIs). DNA was extracted from the blood, and the C677T variant was tested with RFLP-PCR and real-time-PCR. There was no significant influence found for the MTHFR 677 TT genotype on BMI or the obesity risk in codominant, dominant or recessive inheritance models. Individuals with obesity and the TT genotype had significantly lower folate concentrations. After radical weight reduction, the impact of the risk genotype, as well as homeostasis between folate and vitamin B12 in TT homozygotes, seems to be attenuated. Although the MTHFR 677TT genotype is not directly related to a higher BMI in Polish adults, it has a detrimental effect on folate concentrations in individuals with high BMI values.

Relationship between MTHFR C677T, homocysteine, and ischemic stroke in a large sample of the Han Chinese population.

Ischemic stroke, one of the prevalent causes of death and disability worldwide, is linked to environmental and genetic factors, including polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene involved in homocysteine metabolism. The present study aimed to explore the relationship between the MTHFR C677T variant, plasma homocysteine, and risk of developing large-artery atherosclerotic ischemic stroke (LAAIS) among Han Chinese.A population-based case-control study, which included 1810 patients with LAAIS and 1765 unrelated control subjects, was conducted. Compared to the controls, LAAIS patients had a significantly higher prevalence of hypertension, diabetes mellitus, smoking, and alcohol consumption (P < .001), as well as significantly higher mean fasting blood glucose, triglyceride, total cholesterol, and plasma homocysteine levels (P < .001). The TT homozygous genotype correlated with increased risk of developing LAAIS, as indicated by a significantly higher odds ratio (OR) compared to the CT and CC genotypes, in both additive (OR = 3.215, P = .01) and recessive models (OR = 3.265, P = .01). The plasma homocysteine level was genotype-dependent according to the following trend: TT > CT > CC.In conclusion, our data demonstrate that, in spite of its low prevalence in both patients and controls (1.5% vs 0.8%), the MTHFR C677T variant could, at least in part, affect homocysteine levels and this, either alone or in combination with other factors, increases the risk of LAAIS.

A retrospective examination of adjunctive L-methylfolate in children and adolescents with unipolar depression

BackgroundAdjunctive l-methylfolate is commonly prescribed for children and adolescents with treatment-resistant mood disorders; however, the relationship between l-methylfolate augmentation across methylenetetrahydrofolate reductase (MTHFR) genotypes in youths with depressive symptoms is unclear. MethodsWe retrospectively examined the electronic health records of patients (N = 412) with depressive symptoms associated with unipolar depressive disorders and their MTHFR C677T genotypes from 2013 to 2019. Patients were ≤18 years of age at the time of MTHFR pharmacogenetic testing. Treatment response was assessed with Clinical Global Impression–Improvement (CGI-I) score reported in the medical record. ResultsPatients with an MTHFR C677T C/T or T/T genotype were more likely to be prescribed l-methylfolate when the clinician knew their MTHFR genotype (p < 0.0001, OR: 15.1, 95 % CI: [5.1, 44.2]), but not when the clinician did not know their genotype (p = 0.4, OR: 2.1, 95 % CI: [0.4, 11.4]). Change in baseline and endpoint CGI-I scores between patients with an MTHFR C677T variant who were prescribed and not prescribed l-methylfolate did not significantly differ (p = 0.39). Response rate was not associated with l-methylfolate prescription (p = 0.17) or l-methylfolate dose (p = 0.69). LimitationsThis was a retrospective study, which yielded a heterogeneous patient population and limited data availability (e.g., adherence). Patients are severely ill and may have a refractory illness that limits response to adjunctive l-methylfolate. ConclusionClinicians prescribe l-methylfolate to children and adolescents with depressive symptoms associated with unipolar depressive disorders who have an MTHFR C677T variant, although augmentation may not be associated with treatment response, regardless of MTHFR genotype or dose.

Thrombophilic mutations and risk of vascular complications in sickle cell disease

IntroductionSickle cell disease (SCD) is an inherited hemoglobinopathy that is characterized by hemolysis and hypercoagulability. The coinheritance of genetic variants causing thrombophilia may aggravate the hypercoagulable state in SCD patients. The identification of SCD patients with the risk factors for developing thrombosis may play an important role in the prevention and management of vaso-occlusive crises (VOCs) and vascular complications in these patients. The objective of the current case control study was to determine the relationship between thrombophilic variants, methylenetetrahydrofolate reductase (MTHFR) C677T, Factor V Leiden (FVLG1691A), prothrombin gene (PRT) G20210A variants and susceptibility to VOCs and vascular complications in Egyptian SCD patients. Patients and methodsEighty two patients (53 SS, 29 S/β thalassemia) and 70 healthy individuals were genotyped for these thrombophilic variants using PCR-RFLP. Sanger sequencing and real time PCR-based SNP genotyping assay were done for positive cases. ResultsMTHFR C677T was found in 40.2% of cases in heterozygous state (43.4% of SS, 34.5% of S/β thalassemia) with a highly significant difference in the prevalence between cases and healthy subjects (P = 0.001). Heterozygous FVLG1691A mutation was found in 13.4% of cases (15.1% of SS, 10.3% of S/β thalassemia). Seven cases carried both FVLG1691A and MTHFR C677T variants. There was a statistical significant difference between the frequency of acute painful crises and the heterozygosity for MTHFR C677T and FVLG1691A variants (P = 0.003). The heterozygote state of PRT G20210A mutation was present in one SS patient. ConclusionOur data suggested that the MTHFR C677T and FVLG1691A variants have a high impact as risk factors for VOCs in SCD.

Association of MTHFR C677T variant genotype with serum folate and Vit B12 in Iranian patients with colorectal cancer or adenomatous polyps

BackgroundThe incidence of colorectal cancer (CRC) has increased during recent years in Iran and other developing countries. Clinical studies suggest that essential folate dietary intake and moderate deficiency of methylenetetrahydrofolate reductase (MTHFR) may protect and reduce the risk of CRC. The present study aimed to investigate the clinical significance of C677T polymorphism within the MTHFR gene and its correlation with the serum folate and Vit B12 in the Iranian population suffering from CRC.MethodsBlood samples were taken from 1017 Iranian individuals (517 cases and 500 controls) who were referred for colonoscopy. TaqMan probe assay was performed for C677T MTHFR polymorphism. Sera were fractionated from the blood samples of 43 patients and controls and folate and Vit B12 concentrations were measured by a monobind kit. The correlation of MTHFR polymorphisms and folate/vitamin-B12 with CRC risk was analyzed.ResultsIn the current study, we found the frequency of three different genotypes of MTHFR polymorphism in the Iranian population i.e., CC, CT, and TT, to be 51.31, 26.73, 21.96 and 61, 32.2, 6.8 in case and control groups, respectively. The homozygote genotype of MTHFR rs1801133 polymorphism is associated with an increased risk of CRC by 3.68, 1.42, and 3.74-fold in codominant, dominant, and recessive models respectively (p value < 0.01). Our study revealed that there was no significant difference between the amount of folate and Vit B12 in the case and control groups (p value > 0.05).ConclusionsThis study revealed that there was no significant difference between the amount of folate and Vit B12 in the case and control groups. Furthermore, our results demonstrated a higher risk association for 677TT and 677TT + C677T genotypes of MTHFR compared with 677CC carriers among CRC patients.

A Case-Control Study Investigating the Effect of MTHFR C677T Variant on Performance of Elite Athletes.

Increased level of plasma homocysteine (Hcy) is a potential risk factor for several multi-system diseases. The Methylenetetrahydrofolate reductase (MTHFR) gene C677T variant has been established as an important genetic determinant of hyperhomocysteinemia. There are conflicting reports about the effects of physical activity on plasma Hcy. Therefore, the main aim of this study was to investigate whether the MTHFR C677T variant affects elite athletic performance. This study was carried out on 214 individuals (114 elite athletes and 100 sedentary controls). Genotyping was performed using PCR- RFLP method. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. There was a significant difference between the athletes and the control group in genotype distribution and allele frequency of the MTHFR C677T variant. MTHFR C677T CC genotype and C allele were more prevalent in elite athletes than those in the sedentary controls (p =0.007, OR: 2.16, 95%:1.26-3.70; p=0.009, OR: 1.84, 95%:1.18-2.89, respectively). The control group had a higher MTHFR C677T CT genotype than the athletes (p=0.019, OR: 0.51, 95%:0.30-0.88). There was no deviation from HWE for the MTHFR C677T variant in the groups. Our findings support that there is an association between the MTHFR C677T C allele and athletic performance among the elite Turkish athletes.

Associations of Homocysteine Metabolism With the Risk of Spinal Osteoarthritis Progression in Postmenopausal Women.

Although homocysteine accumulation is a reported risk factor for several age-related disorders, little is known about its relationship with osteoarthritis (OA). We investigated for associations of homocysteine and C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR), which is involved in homocysteine clearance, with the development and progression of spinal OA through a combined cross-sectional and longitudinal cohort study. A total of 1306 Japanese postmenopausal outpatients participating in the Nagano Cohort Study were followed for a mean 9.7-year period. Cross-sectional multiple logistic regression for spinal OA prevalence at registration by serum homocysteine level was performed with adjustment for confounders. In addition to Kaplan-Meier analysis, multivariate Cox regression was employed to examine the independent risk of MTHFR C677T variant for spinal OA progression. Multivariate regression analysis revealed a significant association between homocysteine and spinal OA prevalence (odds ratio 1.38; 95% CI 1.14-1.68). Kaplan-Meier curves showed a gene dosage effect of the T allele in MTHFR C677T polymorphism on the accelerated progression of spinal OA severity (P = 0.003). A statistically significant independent risk of the T allele for spinal OA advancement was validated by Cox regression analysis. Respective adjusted hazard ratios for the CT/TT and TT genotypes were 1.68 (95% CI, 1.16-2.42) and 1.67 (95% CI, 1.23-2.28). Circulating homocysteine and C677T variant in MTHFR are associated with the prevalence rate and ensuing progression, respectively, of spinal OA. These factors may represent potential interventional targets to prevent OA development and improve clinical outcomes.

Association of C677T (rs1081133) and A1298C (rs1801131) Methylenetetrahydrofolate Reductase Variants with Breast Cancer Susceptibility Among Asians: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis were conducted to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms with breast cancer (BC) in Asians. Systematic searches were conducted in PubMed, EMBASE, Web of Science, and Scopus by May 2020. Inter-study heterogeneity was also assessed with a Q test, along with I2 statistics. Random-effects models were applied to pooled crude ORs with corresponding 95% CIs for the genetic models. A total of 1097 identified results, along with 36 qualified studies were included: for MTHFR C677T polymorphism, a total of 36 studies was comprised of 11,261 cases and 13,318 controls and for MTHFR A1298C polymorphism, a number of 19 studies contained 7424 cases and 8204 controls. Likewise, for C677T polymorphism, an increased risk of BC was seen for the allelic (OR 1.21, 95% CI 1.09-1.33, P < 0.01, I2 = 78.9%), dominant (OR 1.17, 95% CI 1.05-1.30, P < 0.01, I2 = 71.8%), recessive (OR 1.43, 95% CI 1.23-1.67, P < 0.01, I2 = 55.8%), and homozygous models (OR 1.48, 95% CI 1.25-1.75, P < 0.01, I2 59.9%) among BC patients compared to controls. Also, in terms of A1298C polymorphism, an association was found between the allelic (OR 1.15, 95% CI 1.04-1.28, P < 0.01, I2 70.4%) and homozygous models (OR 1.38, 95% CI 1.15-1.66, P < 0.01, I2 44.2%) with the risk of BC. In conclusion, findings revealed that MTHFR C677T variant might be a factor that predisposes BC in Asians. Furthermore, it was found that A1298C variant acts as a BC risk factor, particularly in a Western Asia population.

Connection between small vessel disease related stroke and the MTHFR C677T polymorphism in a Hungarian population

IntroductionThere are conflicting results in the literature regarding the connection between thrombophilias and ischaemic stroke. However, most of the clinical studies have not differentiated between various ischaemic stroke subtypes. Our aim was to investigate whether there is an association between the methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism and ischaemic stroke due to small vessel disease (SVD) in patients ≤50 years of age. Patients and methodsWe performed a retrospective search in the database used at our Health Centre. Our study population consisted of 100 ischaemic stroke patients. 65 patients had MTHFR C677T variants: 21 were homozygous (TT allele), 45 were heterozygous (CT). 35 stroke patients did not carry MTHFR C677T polymorphism (wild genotype, CC). Stroke subtypes were determined according to the TOAST classification. Pearson's chi-squared test of independence was used to evaluate differences between subgroups and multivariate logistic regression was also performed. ResultsMore than half of our study population (52.00%) had lacunar strokes. The ratio of SVD in patients ≤50 years of age with TT homozygous variant was significantly higher compared to heterozygous and wild type subjects (p = 0.032 and p = 0.03 respectively). Multivariate logistic regression also showed, that apart from hypertension, only TT homozygosity was a predictive factor for SVD related stroke (p = 0.014, OR 1.619, 95% CI 1.390–18.338). ConclusionOur results demonstrate that in a Hungarian population of ischaemic stroke patients ≤50 years of age, SVD is the most common stroke subtype. In addition, we found association of SVD stroke with hypertension and MTHFR 677TT homozygous polymorphism.

Involvement of C677T MTHFR variant but not A1298C in methotrexate-induced toxicity in acute lymphoblastic leukemia.

Methotrexate (MTX) is a key drug in acute lymphoblastic leukemia (ALL) treatment; it inhibits DNA replication by blocking the conversion of 5, 10 Methylenetetrahydrofolate to 5-methylene tetrahydrofolate by methylenetetrahydrofolate reductase (MTHFR). Variants of the Methylenetetrahydrofolate reductase (MTHFR) and MTX related toxicities were largely investigated in several populations, nevertheless, the results are conflicting. This study aimed to assess the prevalence of MTHFR SNVs: C677>T and A1298>C in Tunisian patients with ALL and the relation to the frequency of drug-induced complications. 28 ALL patients were included in the study. They were treated according to EORTOC, in which a high dose of MTX (HDMTX) was prescribed. A toxicity score (ST) is calculated for each patient, summing the grades of toxicities. Genotyping of MTHFR variants was done with a PCR-based restriction fragment length polymorphism assay. The toxicity's score (TS) was higher with C677T variant compared to wild genotype (C677C) (TS = 4; IC95% [-2.65-13.32] versus TS = 2.5; IC95% [1.65-4.55], respectively; p = 0.2); but lower with the A1298C mutation compared to those with the wild genotype (A1298A) (TS = 2.5; IC95% [0.48-4.77], versus TS =3; IC95% [1.9-5.69], p = 0.4). HDMTX-related toxicity is associated with the 677CT genotype in ALL patients (RR = 1.41, p = 0.2); not for the A1298C [OR = 0.46, [0.08-2.61], p = 0.18]. Our preliminary findings highlight the impact of the C677T variant of MTHFR, but not the A1289C; in HD-MTX chemotherapy-related adverse effects in younger Tunisian ALL.

Methylenetetrahydrofolate Reductase (MTHFR) C677T and A1298C Polymorphisms in Georgian Females with Hypothyroidism.

The aim of this study was to investigate the frequency of methylenetetrahydrofolate reductase ( MTHFR) gene polymorphisms in Georgian females with hypothyroidism. Thirty-four patients and 29 healthy individuals were recruited in this study. Polymerase chain reaction-restriction fragment length polymorphism analyses were used for genotyping of MTHFR polymorphisms. The results of this study suggest that the MTHFR C677T variant was significantly associated with hypothyroidism. In addition, in individuals with T allele risk of hypothyroidism significantly increased. Combination of CT/AA genotypes was more prevalent in the hypothyroid patients than in the control group. Thus, C677T polymorphism could be a possible genetic factor contributing to the pathophysiology of hypothyroidism, possibly through hyperhomocysteinemia.

Association between A1298C and C677T methylenetetrahydrofolate reductase gene polymorphisms and the risk of acute lymphoid and myeloid leukemia

Background: Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme involved in folate metabolism, DNA methylation and synthesis. Two MTHFR polymorphisms, C677T and A1298C, have been associated with reduced enzyme activity. Rapidly replicating cell types, such as hematopoietic cells, may be especially sensitive to changes in the availability of intracellular folate. The aim of this case-control study was to evaluate whether the mentioned polymorphisms in MTHFR gene plays a role in altering susceptibility to acute myeloid leukemia and acute lymphoblastic leukemia. Material and methods: 281 patients comprising 101 patients with acute lymphoblastic leukemia and 180 patients with acute myeloid leukemia as well as 490 normal individuals as control group were studied for the C677T and the A1298C MTHFR gene polymorphisms using PCR. The PCR products were digested with HinfI and Mbo‌‌‌‌‌II restriction enzymes respectively (RFLP). The results were electrophoresed on agaros gel and analyzed using SPSS software. Results: The number of patients with acute lymphoblastic leukemia who had C677T polymorphism was less than the control group, but this difference was not significant. Also, combination of C677T/A1298C genotypes in both case and control groups, showed no increase of susceptibility to acute myeloid leukemia and/or acute lymphoblastic leukemia risk. There was no significant relationship between common MTHFR variants and the risk of acute myeloid leukemia and acute lymphoblastic leukemia in controls and the cases. Conclusion: Our findings showed that the MTHFR C677T and A1298C gene variants do not have a major influence on the susceptibility to acute lymphoblastic leukemia and acute myeloid leukemia in Iranian individuals. However, the C677T polymorphism has a protection role in acute lymphoblastic leukemia group, but this difference was not statistically significant.

The association of MTHFR C677T variant with increased risk of ischemic stroke in the elderly population: a meta-analysis of observational studies

BackgroundC677T point mutation in methylenetetrahydrofolate reductase (MTHFR) gene have been found to be associated with ischemic stroke in general population, while the results seem inconsistent. We aim to assess the association between variant MTHFR C677T variant and increased risk of ischemic stroke and focus on the elderly population.MethodsWe searched PubMed, Embase, Cochrane Library, and Web of Science for eligible studies. Odds ratios (ORs) were calculated with the two-tailed 95% confidence intervals (CIs) by using a random effects model to evaluate any possible association. Among the Chinese and non-Chinese populations, we conducted a subgroup analysis.ResultsThe electronic database search yielded 1,358 citations as of December 2017; finally, nine case-control studies involving 3,337 subjects fulfilled our eligibility criteria for inclusion in the study. The pooled results showed that MTHFR C677T variant increased the risk of ischemic stroke (OR = 1.23, 95%CI 1.06–1.43, P = 0.0067 for CT + TT vs. CC; OR = 1.18, 95%CI 1.01–1.38, P = 0.0333 for CT vs. CC; OR = 1.41, 95%CI 1.14–1.75, P = 0.0016 for TT vs. CC; OR = 1.27, 95%CI 1.05–1.54, P = 0.0145 for TT vs. CC + CT; OR = 1.18, 95%CI 1.06–1.31, P = 0.0023 for T-allele vs. C-allele). Further subgroup analyses in the Chinese population indicated that MTHFR C677T variant was associated with a higher risk of ischemic stroke.ConclusionOur findings showed that T-allele increases risk for stroke in the pooled sample. This association was statistically significant in the Chinese cohorts and showed a similar trend in the non-Chinese cohorts. (Word count: 237).

Comprehensive analysis of Methylenetetrahydrofolate reductase C677T in younger acute lymphoblastic leukemia patients: A single-center experience.

Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms, mainly the C677T, have been implicated as risk factors for several cancers as the acute lymphoblastic leukemia (ALL). In addition, a potential effect of such variant on the efficacy of methotrexate (MTX) has been reported. In this study, we evaluated the impact of the C677T variant of MTHFR on MTX-related toxicity in ALL patients from Tunisia; to provide new insights for a personalized therapy based on the human genotype. Genotyping was carried out with restriction fragment length polymorphism (RFLP) on blood samples from a total of 35 younger patients; suffering from ALL. In the ALL patients, the MTHFR 677CT genotype confers a greater risk of toxicity with 1.3 times as relative risk mainly the hepatic toxicity when compared with MTHFR 677CC. Our findings suggest that C677T polymorphism of MTHFR seems to be a good marker for MTX-related toxicity in ALL.

Influence of MSI and 18q LOH markers on capecitabine adjuvant monotherapy in colon cancer patients.

PurposeThe aim of this study was to evaluate whether pretreatment analysis of selected molecular markers can be used for the prediction of disease-free survival (DFS)/overall survival (OS) of capecitabine adjuvant monotherapy in colon cancer patients.Patients and methodsA total of 126 patients enrolled in a capecitabine Phase IV clinical trial were analyzed for microsatellite instability (MSI), 18q loss of heterozygosity (LOH), thymidylate synthase (TYMS) 5′ variable number of tandem repeat (VNTR), and methylene tetrahydrofolate reductase (MTHFR) C677T variants. The significance in predicting 5-year DFS/OS was assessed by Kaplan–Meier and Cox regression analyses.ResultsThe MSI-high (MSI-H) genotype was significantly associated with DFS (HR 0.205, 95% CI 0.05–0.88, P=0.033) and OS (HR 0.208, 95% CI 0.05–0.89, P=0.035) compared to the microsatellite stable genotype. In models stratified according to clinicopathologic characteristics, the MSI-H genotype remained a positive predictive factor for DFS/OS only in patients with stage III (P=0.023) and patients with tumors localized proximally to the splenic flexure (P=0.004). Distal colon cancers with 18q LOH have a greater survival rate when treated with capecitabine than patients with stable tumors (81.3% vs 50.0%, HR for relapse 0.348, 95% CI 0.13–0.97, P=0.043). TYMS 5′VNTR and MTHFR C677T variants were not associated with DFS or OS.ConclusionMSI and 18q LOH markers have the potential to be utilized in the selection of colon cancer patients eligible for capecitabine adjuvant monotherapy.

A12999 The Methylenetetrahydrofolate Reductase C677T Gene Variant as a Risk Factor for Hypertension in a Rural Indonesian-Sundanese Population

Objectives: Methylenetetrahydrofolate Reductase (MTHFR) C677T gene variant is associated with hypertension depending on ethnic and geographic region. Several studies found that the affordable and widely available riboflavin or vitamin B2 as a cofactor of MTHFR could lower blood pressure in patients with MTHFR variants. The benefits of risk stratification and therapeutic potential made it interesting to be studied. No study of MTHFR C677T variant effect on hypertension is available in Indonesia. This study sought to determine the association of MTHFR C677T gene variant and hypertension in rural Sundanese population of Gunung Sari Village, Bogor-Indonesia. Methods: A total of 415 subjects consisting of 213 hypertensive subjects and 202 non-hypertensive subjects as a control group were enrolled in this population based case-control study. The genotypes of the MTHFR C677T were determined by a TaqMan assay. Odds ratio with 95 % confidence interval was used to assess the risk of association. Results: There was a significant difference of MTHFR C677T variant between hypertensive group and control group; 62.9% CC; 34.3% CT; 2.8% TT vs 77.7% CC; 20.8% CT; 1.5% TT with p = 0.004; and mutant (TT and CT) vs wild type genotype (CC) with p = 0.001 respectively. After adjustment of age, body mass index, waist circumference, and diabetes mellitus, there was an association between MTHFR C677T variant with hypertension (OR 2.1; 95% CI 1.3–3.5). Conclusion: MTHFR C677T gene variant increased the risk of hypertension in rural Indonesian-Sundanese population. Further studies in different areas in Indonesia may be conducted.

Methylenetetrahydrofolate reductase C677T variant and hyperhomocysteinemia in subarachnoid hemorrhage patients from India.

Methylenetetrahydrofolate reductase (MTHFR) polymorphism (C677T, A1298C) has been implicated in increased plasma homocysteine (Hcy) levels. The present study was designed to investigatethe association between MTHFR polymorphism and increased Hcy levels in subarachnoid haemorrhage (SAH) patients. A total of 150 subjects from North India were included in the study, comprising of 100 SAH patients and 50 healthy controls. Plasma Hcy levels was determined and MTHFR polymorphism (C677T, A1298C) was screened by High resolution melting (HRM) analysis. Plasma Hcy levels were found to be significantly higher (p < 0.001) in SAH patients than in healthy controls. No significant difference in the genotype and allele frequency of MTHFR A1298C was observed. However, frequency of MTHFR C677T genotype, CT (53% vs. 20%; p < 0.001) and TT (15% vs. 2%; p < 0.05) was significantly higher in SAH group as compared to healthy controls. The frequency of T allele (41.5% vs. 12%; p < 0.001) was also found to be higher in SAH patients in comparison to healthy controls. Furthermore, Hcy levels were higher in SAH patients with TT genotype than in patients having CT genotype, whereas CC genotype had lower Hcy levels. The study suggests that higher frequency of MTHFR C677T allele may contribute to etiopathology of SAH through increase in Hcy levels.