Doubly bi-allelic variants of MTHFR and MTHFD1 in a Chinese patient with hyperhomocysteinemia and failure of folic acid therapy

Background: Hyperhomocysteinemia (HHcy) is a risk factor for thromboembolic disease. Defects in one-carbon metabolism (1-CM)-related genes, such as methylenetetrahydrofolate reductase (MTHFR), methylenetetrahydrofolate dehydrogenase, cyclohydrolase, and formyltetrahydrofolate synthetase 1 (MTHFD1), can cause HHcy and may also affect the efficacy of folic acid therapy. The details of mechanisms are yet to be further investigated. Method: We described a Chinese family with hereditary HHcy. The proband suffered from severe thromboembolic disease and experienced failure of folic acid therapy. Two sons of the proband were also diagnosed with HHcy but were sensitive to folic acid therapy. Whole-exome sequencing (WES) was conducted to evaluate the genetic lesion of this family. Results: Compound heterozygous variants (a common polymorphism, p. A222V, and a novel variant, p. C631*fs*1) of the MTHFR gene and a homozygous missense variant (p. K134R) of the MTHFD1 gene were identified in the proband. The two sons, with successful intervention, only harbored the homozygous p. A222V variant of the MTHFR gene. Conclusion: The clinical manifestations and genetic research synergistically confirmed the diagnosis of HHcy and clarified the failure of folic acid therapy in the proband caused by doubly bi-allelic variants of the MTHFR and MTHFD1 genes. Our study increased our understanding of the molecular basis of 1-CM-related gene defects on folic acid therapy in HHcy.

[Indirect molecular genetic predisposition factors to increased thrombosis in sufferers with mechanical lower limb trauma]

THE AIM OF THE STUDY

Was to selectively determine the occurrence frequency of polymorphic alleles in candidate genes of hereditary predisposition to increased thrombosis (T) in persons with mechanical trauma of musculoskeletal system (MS), who died from pulmonary artery thromboembolia (PATE). A total of 48 deaths from PATE cases of sufferers with MS trauma. The character of single nucleotide polymorphisms carriage (SNPC) in 13 candidate genes of hereditary predisposition to increased T (in genes, responsible for the synthesis of plasma proteins of the hemostatic system, platelet factors affecting tension of vessel wall and folate cycle) was determined. It has been established that the most common «mutant» alleles are found in PAI-1 -675 5G/4G, MTHFR 677 CT and MTRR 66AG genes, and in 87.8, 53.85 and 75.0% of the analysed cases, respectively. The consideration of SNP carriage character in the genes of predisposition to increased T is required for the full expert judgement on the causality between a mechanical trauma and PATE.

MTHFR Polymorphisms and Cardiac Parameters in Patients with Diabetic Retinopathy

BACKGROUND

Diabetes Mellitus (DM) is directly associated with cardiovascular dysfunctions and microvascular complications, such as diabetic retinopathy (DR). The association between DR and increased risks of developing cardiovascular diseases has been described. The low activity of the Methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in the metabolism of homocysteine, can lead to hyperhomocysteinemia that has already been related to cardiac outcomes and resistance to insulin. The A1298C and C677T polymorphisms in the MTHFR can reduce enzyme activity.

OBJECTIVE

The study aims to analyze the association between MTHFR genotypes and cardiac parameters in patients with DR.

METHODS

DM patients diagnosed with DR (n=65) were categorized and compared according to MTHFR genotypes A1298C (AA and AC+CC groups) and C677T (CC and CT+TT) groups; biochemical, cardiological, anthropometric, genetic, lifestyle and vitamin B9 and B12 consumption variables. Fischer's exact test and Poisson regression were performed to assess the relationship between variables.

RESULTS

Comparing echocardiographic and electrocardiogram parameters within genotypic groups, we found a significant association between left atrial dilation and C677T polymorphism. Left atrium diameter was higher in the T allele carriers (CT+TT group), with a prevalence ratio of 0.912. This association was confirmed in the regression model, including confounding variables. The other cardiac structural and functional parameters studied were not significantly associated with the A1298C or C677T genotypes.

CONCLUSION

The MTHFR C677T genotype may contribute to atrial remodeling in RD patients. We found an association between the diameter of the left atrium and the T allele of the MTHFR C677T polymorphism in patients with DR.

Effects of Methylenetetrahydrofolate Reductase (MTHFR) Polymorphisms on Retinal Tissue Perfusion in Mild Diabetic Retinopathy Patients Receiving the Medical Food, Ocufolin®

Purpose

We evaluate the effects of methylenetetrahydrofolate reductase (MTHFR) polymorphisms on retinal tissue perfusion in patients with mild diabetic retinopathy (DR + PM) taking the medical food, Ocufolin^®, for 6 months.

Methods

Prospective, case-controlled study. Eight early diabetic retinopathy patients with common reduced function MTHFR polymorphisms (DR+PM) and 15 normal controls (NC) were recruited. MTHFR polymorphisms were subtyped as normal, C677T, or A1298C. Best corrected visual acuity (BCVA) was evaluated. Retinal blood flow velocity (BFV) was measured using Retinal Function Imager. Retinal tissue perfusion (RTP, blood flow rate per inner retinal volume) was calculated within a 2.5 mm diameter circle centered on the fovea. The medical food is intended to address ocular ischemia with high doses of vitamin B-complexes and antioxidants, including L-methylfolate, methylcobalamin, zinc, copper, lutein, vitamins C, D, E, and n-acetylcysteine. The subjects were provided with a medical food for a period of 6 months.

Results

BCVA and vascular indices of DR + PM patients at baseline were initially below those of NC and improved after medical food. Compared to baseline, DR + PM patients after the medical food had significantly improved BCVA during the follow-up period (P < 0.05). In comparison, overall RTP and arteriolar BFV were significantly increased at 6 months (P < 0.05). The changes varied with MTHFR subtypes. In patients with the C677T and the C677T/A1298C compound mutations, RTP was increased at 6 months as compared to that at baseline and 4 months (P < 0.05). In patients with only the A1298C mutation, all microcirculation metrics were increased from baseline at 4 and 6 months, but with less improvement at 6 months than at 4 months (P < 0.05).

Conclusion

Medical food was effective in improving both visual acuity and retinal tissue perfusion in DR + PM patients. The degree of improvement of retinal microcirculation varied among MTHFR subtypes.

Homocysteine levels, genetic background, and cognitive impairment in Parkinson's disease

BACKGROUND

Hyperhomocysteinemia is considered an independent risk factor for cognitive impairment.

OBJECTIVE

To study the correlation between homocysteine levels and cognitive impairment in patients with PD.

METHODS

We conducted a case-control study that included 246 patients with PD, of whom 32 were cognitively impaired. The levels of homocysteine, folate, and vitamin B12 were measured in peripheral blood. Multivariate logistic regression analysis was applied to determine differences in homocysteine levels between PD patients with and without cognitive impairment. A meta-analysis was performed to clarify the role of Hcy levels in PD with cognitive decline. Five polymorphisms in genes involved in Hcy metabolism, including MTHFR rs1801133 and rs1801131, COMT rs4680, MTRR rs1801394, and TCN2 rs1801198, were genotyped.

RESULTS

Our case-control study showed that homocysteine levels were associated with cognitive impairment in PD after adjusting for possible confounding factors such as levodopa equivalent daily dose. The results of our meta-analysis further supported the positive association between homocysteine levels and cognition in PD. We found that the MTHFR rs1801133 TT genotype led to higher homocysteine levels in PD patients, whereas the MTHFR rs1801131 CC genotype resulted in higher folate levels. However, the polymorphisms studied were not associated with cognitive impairment in PD.

CONCLUSIONS

Increased homocysteine levels were a risk factor for cognitive decline in PD. However, no association was found between polymorphisms in genes involved in homocysteine metabolism and cognitive impairment in PD. Large-scale studies of ethnically diverse populations are required to definitively assess the relationship between MTHFR and cognitive impairment in PD.

MTHFR and MTRR Genetic Polymorphism of Methotrexate Therapy Outcomes in Early Rheumatoid Arthritis

Purpose

Methotrexate (MTX) is used as an anchor drug for the treatment of rheumatoid arthritis (RA) and there may be differences in drug action between genotypes. The purpose of this study was to investigate the relationship between clinical efficacy response and disease activity of MTX monotherapy with methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) polymorphisms.

Patients and Methods

In the study, a population of 32 patients in East China with early RA fulfilling the diagnostic standards of the American College of Rheumatology (ACR) were enrolled, all of them received MTX monotherapy. Genotyping of patients MTHFR C677T and A1298C, MTRR A66G using tetra-primer ARMS-PCR method and sanger sequencing to verify its accuracy.

Results

The distribution of three polymorphic genotypes that were studied is in accordance with the Hardy-Weinberg genetic equilibrium. The patient pathology variables smoke (OR = 0.088, P = 0.037), drink alcohol (OR = 0.039, P = 0.016) and males (OR = 0.088, P = 0.037) were significantly associated with non-response to MTX. Genotype, allele distribution and genetic statistical models were not found to be related to MTX treatment response and disease activity in both the response groups and non-response groups.

Conclusion

Our findings suggest that the MTHFR C677T, MTHFR A1298C and MTRR A66G polymorphisms may not predict MTX clinical treatment response and disease activity in patients with early RA. The study revealed that smoke, alcohol, and males were possible influential factors for MTX non-response.

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.

Association of homocysteine and polymorphism of methylenetetrahydrofolate reductase with early-onset post stroke depression

Background

Homocysteine (Hcy) has been indicated to be involved in pathophysiology of post stroke depression (PSD). There is a lack of research to study the relationship between Hcy metabolism genes and PSD. Our study aims to investigate the relationship among Hcy metabolism genes, Hcy, and early-onset PSD.

Materials and methods

We recruited 212 patients with stroke and collected their peripheral blood sample, clinical data, and laboratory test on admission. 12 single nucleotide polymorphisms (SNPs) in methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), and methionine synthase (MTR) genes were genotyped by high-resolution melt analysis. PSD was diagnosed by DSM-V at 2 weeks after stroke. Binary logistic regression and haplotype analysis were used to examine the association between Hcy metabolism genes and PSD. Mediation analysis was performed to clarify whether the SNPs exerted their effect on PSD by affecting the Hcy level.

Results

81 patients were diagnosed with PSD, and the incidence rate was 38.2%. Hcy level in PSD group was significantly higher than it in non-PSD group (p = 0.019). MTHFR rs1801133 AA genotype an A allele were associated with an elevated risk of PSD after adjustment for some confounding factors (OR = 4.021, 95% CI: 1.459∼11.080, p = 0.007 for AA genotype; OR = 1.808, 95% CI: 1.172∼2.788, p = 0.007 for A allele). Furthermore, the effect of MTHFR rs1801133 AA genotype on PSD was mediated by Hcy (OR = 1.569, 95% CI: 0.013∼3.350, p < 0.05).

Conclusion

MTHFR rs1801133 and Hcy were associated with PSD, and MTHFR rs1801133 may exert an effect on PSD via mediating Hcy level. This offers a new perspective for treating PSD and understanding the mechanism of PSD.

Association between maternal MTHFR C677T/A1298C combination polymorphisms and IVF/ICSI outcomes: a retrospective cohort study

STUDY QUESTION

What are the roles of maternal 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T/A1298C combination polymorphisms on the embryological and clinical outcomes of IVF/ICSI?

SUMMARY ANSWER

Our study reveals for the first time that the oocyte maturation potential gradually decreases with a reduction of maternal MTHFR activity determined by combined C677T/A1298C polymorphisms, while embryo quality was worse in women with intermediate MTHFR activity.

WHAT IS KNOWN ALREADY

Although many previous studies have explored the association between MTHFR polymorphisms and IVF/ICSI outcomes, the results remain contradictory due to inadequate samples, no adjustment for potential confounders and/or the study of C677T and A1298C separately. Few studies have systematically investigated the exact role of MTHFR activity determined by combined C677T/A1298C polymorphisms on the embryological and clinical outcomes of IVF/ICSI.

STUDY DESIGN SIZE DURATION

This is a retrospective cohort study investigating 1160 women who were referred for MTHFR genotyping and IVF/ICSI treatment at Peking University Third Hospital from May 2017 to May 2020.

PARTICIPANTS/MATERIALS SETTING METHODS

Women who were referred for MTHFR genotyping and their first IVF/ICSI treatment at our hospital were included and those undergoing preimplantation genetic testing cycles were excluded. The included women were divided into different cohorts according to their C677T, A1298C and combined C677T/A1298C genotypes. The embryological outcomes, including oocytes retrieved, metaphase II oocytes, oocyte maturation rate, normal fertilization rate and transplantable embryo rate, were evaluated by generalized linear regression models. The clinical outcomes, including biochemical pregnancy rate, clinical pregnancy rate and live birth rate, were evaluated by log-binomial regression models. All outcomes were adjusted for potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with the combined 677TT/1298AA genotype (hereafter abbreviated as TT/AA, as with other combined genotypes), whose enzyme activity was the lowest, had a lower oocyte maturation rate compared with those with the wild-type genotype (P = 0.007). Moreover, the oocyte maturation rate decreased linearly with the decline in MTHFR enzyme activity determined by combined C677T/A1298C genotypes (P-trend = 0.001). The combined CC/AC, CC/CC&CT/AA and CT/AC genotypes with intermediate enzyme activity were associated with a lower transplantable embryo rate (P = 0.013, 0.030 and 0.039, respectively). The differences in clinical outcomes between women with wild-type genotype and combined C677T/A1298C variant genotypes were not significant.

LIMITATIONS REASONS FOR CAUTION

Our study population had comparable embryological outcomes but worse clinical outcomes than other women undergoing IVF/ICSI treatment at our hospital. Therefore, the results related to the clinical outcomes should be generalized with caution. In addition, we did not detect the folate concentration of each patient during pregnancy. However, this might not have much influence on our results because almost all of our study participants took sufficient folic acid around pregnancy.

WIDER IMPLICATIONS OF THE FINDINGS

We provide a holistic view of the effect of MTHFR C677T and A1298C polymorphisms on the IVF/ICSI outcomes, which can contribute to providing reasonable folic acid supplementation suggestions for women with different MTHFR genotypes, especially for those with a low oocyte maturation rate and/or low embryo quality.

STUDY FUNDING/COMPETING INTERESTS

This work was funded by the National Natural Science Foundation of China (31871447, and 82101677), the National Key Research and Development Program (2019YFA0801400) and the Natural Science Foundation of Beijing Municipality (7202226). The authors declare that they have no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

The 677C > T variant in methylenetetrahydrofolate reductase causes morphological and functional cerebrovascular deficits in mice

Vascular contributions to cognitive impairment and dementia (VCID) particularly Alzheimer's disease and related dementias (ADRDs) are increasing; however, mechanisms driving cerebrovascular decline are poorly understood. Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in the folate and methionine cycles. Variants in MTHFR, notably 677 C > T, are associated with dementias, but no mouse model existed to identify mechanisms by which MTHFR677C > T increases risk. Therefore, MODEL-AD created a novel knock-in (KI) strain carrying the Mthfr677C > T allele on the C57BL/6J background (Mthfr677C > T) to characterize morphology and function perturbed by the variant. Consistent with human clinical data, Mthfr677C > T mice have reduced enzyme activity in the liver and elevated plasma homocysteine levels. MTHFR enzyme activity is also reduced in the Mthfr677C > T brain. Mice showed reduced tissue perfusion in numerous brain regions by PET/CT as well as significantly reduced vascular density, pericyte number and increased GFAP-expressing astrocytes in frontal cortex. Electron microscopy revealed cerebrovascular damage including endothelial and pericyte apoptosis, reduced luminal size, and increased astrocyte and microglial presence in the microenvironment. Collectively, these data support a mechanism by which variations in MTHFR perturb cerebrovascular health laying the foundation to incorporate our new Mthfr677C > T mouse model in studies examining genetic susceptibility for cerebrovascular dysfunction in ADRDs.

MTHFR epigenetic derepression protects against diabetes cardiac fibrosis

BACKGROUND

Diabetes cardiac fibrosis is associated with altered DNA methylation of fibrogenic genes; however, the underlying mechanisms remain unclear.

OBJECTIVES

In this study, we investigate the critical role of DNA methylation aberration-associated suppression of MTHFR in diabetes cardiac fibrosis, and the protective effects of folate on diabetes cardiac fibrosis, using cultured cells, animal models, and clinical samples.

METHODS AND RESULTS

Herein, we report that DNA methylation repression of MTHFR, critically involved in diabetes cardiac fibrosis, mediates the significant protective effects of folate in a mouse model of diabetes cardiac fibrosis induced by STZ. Heart MTHFR expression was markedly suppressed in diabetes cardiac fibrosis patients and mice, accompanied by increased DNMT3A and MTHFR promoter methylation. Knockdown of DNMT3A demethylated MTHFR promoter, recovered the MTHFR loss, and alleviated the diabetes cardiac fibrosis pathology and cardiac fibroblasts pyroptosis. Mechanistically, DNMT3A epigenetically repressed MTHFR expression via methylation of the promoter. Interestingly, folate supplementation can rescue the effect of MTHFR loss in diabetes cardiac fibrosis, suggesting that inactivation of MTHFR through epigenetics is a critical mediator of diabetes cardiac fibrosis.

CONCLUSIONS

The current study identifies that MTHFR repression due to aberrant DNMT3A elevation and subsequent MTHFR promoter hypermethylation is likely an important epigenetic feature of diabetes cardiac fibrosis, and folate supplementation protects against diabetes cardiac fibrosis.

Vitamin B-6 and riboflavin, their metabolic interaction, and relationship with MTHFR genotype in adults aged 18-102 years

BACKGROUND

The generation of the active form of vitamin B-6, pyridoxal 5'-phosphate (PLP), in tissues is dependent upon riboflavin as flavin mononucleotide, but whether this interaction is important for maintaining vitamin B-6 status is unclear.

OBJECTIVE

To investigate vitamin B-6 and riboflavin status, their metabolic interaction, and relationship with methylenetetrahydrofolate reductase (MTHFR) genotype in adulthood.

METHODS

Data from 5612 adults aged 18-102 y were drawn from the Irish National Adult Nutrition Survey (NANS; population-based sample) and the Trinity-Ulster Department of Agriculture (TUDA) and Genovit cohorts (volunteer samples). Plasma PLP and erythrocyte glutathione reductase activation coefficient (EGRac), as a functional indicator of riboflavin, were determined.

RESULTS

Older (≥65 y) compared with younger (<65 y) adults had significantly lower PLP concentrations (P < 0.001). A stepwise decrease in plasma PLP was observed across riboflavin categories, from optimal (EGRac ≤1.26), to suboptimal (EGRac: 1.27-1.39), to deficient (EGRac ≥1.40) status, an effect most pronounced in older adults (mean ± SEM: 76.4 ± 0.9 vs 65.0 ± 1.1 vs 55.4 ± 1.2 nmol/L; P < 0.001). In individuals with the variant MTHFR 677TT genotype combined with riboflavin deficiency, compared with non-TT (CC/CT) genotype participants with sufficient riboflavin, we observed PLP concentrations of 52.1 ± 2.9 compared with 76.8 ±0.7 nmol/L (P < 0.001). In participants with available dietary data (i.e., NANS cohort, n = 936), PLP was associated with vitamin B-6 intake (nonstandardized regression coefficient β: 2.49; 95% CI 1.75, 3.24; P < 0.001), supplement use (β: 81.72; 95% CI: 66.01, 97.43; P < 0.001), fortified food (β: 12.49; 95% CI: 2.08, 22.91; P = 0.019), and EGRac (β: -65.81; 95% CI: -99.08, -32.54; P < 0.001), along with BMI (β: -1.81; 95% CI: -3.31, -0.30; P = 0.019).

CONCLUSIONS

These results are consistent with the known metabolic dependency of PLP on flavin mononucleotide (FMN) and suggest that riboflavin may be the limiting nutrient for maintaining vitamin B-6 status, particularly in individuals with the MTHFR 677TT genotype. Randomized trials are necessary to investigate the PLP response to riboflavin intervention within the dietary range. The TUDA study and the NANS are registered at www.ClinicalTrials.gov as NCT02664584 (27 January 2016) and NCT03374748 (15 December 2017), respectively.Clinical Trial Registry details: Trinity-Ulster-Department of Agriculture (TUDA) study, ClinicalTrials.gov no. NCT02664584 (January 27th 2016); National Adult Nutrition Survey (NANS), ClinicalTrials.gov no. NCT03374748 (December 15th 2017).

Intracellular Metabolomics Identifies Efflux Transporter Inhibitors in a Routine Caco-2 Cell Permeability Assay-Biological Implications

Caco-2 screens are routinely used in laboratories to measure the permeability of compounds and can identify substrates of efflux transporters. In this study, we hypothesized that efflux transporter inhibition of a compound can be predicted by an intracellular metabolic signature in Caco-2 cells in the assay used to test intestinal permeability. Using selective inhibitors and transporter knock-out (KO) cells and a targeted Liquid Chromatography tandem Mass Spectrometry (LC-MS) method, we identified 11 metabolites increased in cells with depleted P-glycoprotein (Pgp) activity. Four metabolites were altered with Breast Cancer Resistance (BCRP) inhibition and nine metabolites were identified in the Multidrug Drug Resistance Protein 2 (MRP2) signature. A scoring system was created that could discriminate among the three transporters and validated with additional inhibitors. Pgp and MRP2 substrates did not score as inhibitors. In contrast, BCRP substrates and inhibitors showed a similar intracellular metabolomic signature. Network analysis of signature metabolites led us to investigate changes of enzymes in one-carbon metabolism (folate and methionine cycles). Our data shows that methylenetetrahydrofolate reductase (MTHFR) protein levels increased with Pgp inhibition and Thymidylate synthase (TS) protein levels were reduced with Pgp and MRP2 inhibition. In addition, the methionine cycle is also affected by both Pgp and MRP2 inhibition. In summary, we demonstrated that the routine Caco-2 assay has the potential to identify efflux transporter inhibitors in parallel with substrates in the assays currently used in many DMPK laboratories and that inhibition of efflux transporters has biological consequences.

Triglyceride Level- and MTHFR- Specific Mediation Effect of Handgrip Strength on the Association of Dietary Protein Intake and Cognitive Function in the Chinese Elderly

BACKGROUND

Recent findings suggest that both dietary protein intake and hand grip strength (HGS) were associated with cognitive function, however, few studies have been devoted specifically to the mediation effect of HGS on the association of dietary protein with cognitive function.

OBJECTIVES

To confirm the hypothesis that HGS mediated the association of dietary protein intake with cognitive function in the elderly, which was modified by triglyceride level and methylenetetrahydrofolate reductase (MTHFR) gene status.

METHODS

This cross-sectional study included 3,268 participants. Dietary protein intake, HGS, and cognitive function were collected by food frequency questionnaires (FFQ), grip measurements and mini mental state examination (MMSE), respectively. In this mediation analysis, dietary protein intake was entered as independent variable, HGS was entered as mediator, and cognitive function was entered as dependent variable.

RESULTS

HGS significantly mediated the associations of dietary protein (β = 0.0013, 95% CI: 0.0007, 0.0022), animal protein (β = 0.0024, 95% CI: 0.0012, 0.0037), and plant protein intake (β = 0.0011, 95% CI: 0.0001, 0.0023) with cognitive function in total participants, with the mediated proportion of 16.19%, 12.45% and 20.57%, respectively. Furthermore, significant mediation effects of HGS on the associations of dietary protein, animal protein, and plant protein intake with MMSE score were found in the elderly without hypertriglyceridemia or in MTHFR C677T CC/CT carriers.

CONCLUSION

This study suggested that HGS mediated the association of dietary protein intake with cognitive function, and this mediation effect was modified by triglyceride level and MTHFR C677T gene status.

Associations Between microRNA-related Genetic Polymorphisms and Clinical Response to Methotrexate in Chinese Rheumatoid Arthritis Patients

BACKGROUND

Emerging evidence indicates that microRNA (miRNA)-related genetic polymorphisms are strongly involved in the post-transcriptional regulation of the expression of pharmacokinetics and pharmacodynamics- related genes, therefore contributing to the genetic variability of drug response.

OBJECTIVE

To investigate the associations of miRNA-related genetic polymorphisms, including miRNA-5189 rs562929801, miRNA-595 rs4909237, SLCO1A2 rs4149009 and MTHFR rs3737966, and clinical response to methotrexate in Chinese rheumatoid arthritis patients.

METHODS

One hundred patients treated with MTX for approximately 3 months were prospectively followed up to evaluate the clinical response according to European League Against Rheumatism (EULAR) good and moderate response, disease activity score in 28 joint counts - erythrocyte sedimentation rate (DAS28-ESR) low disease activity (LDA) and remission (REM), change in DAS28-ESR (ΔDAS28-ESR) and ΔDAS28-ESR > 0.6. Genetic polymorphisms were genotyped utilizing the HI-SNP technology.

RESULTS

Of the 100 patients with a mean age of 52.23 ± 12.71 years, 81 patients were female (81.00%). After adjusting potential confounders, the major allele of miRNA-5189 rs562929801 was found to be significantly associated with EULAR response (A/A + A/G versus G/G, RR = 0.81, 95% CI = 0.67-0.99, P = 0.04) and ΔDAS28-ESR > 0.6 under dominant model (A/A + A/G versus G/G, RR = 0.83, 95% CI = 0.71-0.98, P = 0.03). However, nonsignificant evidence was detected for the remaining three miRNA-related genetic polymorphisms in neither univariable analysis nor multivariable analysis.

CONCLUSION

Our results indicated that miRNA-5189 rs562929801 was significantly associated with clinical response to MTX, and this association warrants further replication studies with larger sample sizes.

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

BACKGROUND

Adjunctive 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.

METHODS

We 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.

RESULTS

Patients 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).

LIMITATIONS

This 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.

CONCLUSION

Clinicians 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.

The Effect of 3-Week Betaine Supplementation on Blood Biomarkers of Cardiometabolic Health in Young Physically Active Males

Betaine (BET) supplementation decreases homocysteine concentration in plasma, but it may also have an adverse effect on health by increasing blood lipid concentrations, at least in overweight and obese individuals. The aim of this study was to evaluate the effect of BET supplementation on the lipid profile and concentrations of homocysteine, inflammatory cytokines, and liver enzymes in physically active, healthy males. This was a randomized, placebo (PL)-controlled, double-blinded, crossover trial. BET (2.5 or 5.0 g/d) was administered for 21 days. Before and after supplementation with BET or PL, anthropometric measurements and blood were collected in a fasted state. Our results show that BET supplementation significantly decreased homocysteine concentration (from 17.1 ± 4.0 μmol/L before BET to 15.6 ± 3.5 μmol/L after BET, p = 0.009, η² = 0.164). However, the intervention had no effect on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerol, interleukins 1β and 6, and tumour necrosis factor α concentrations, or alanine and aspartate activities. In addition, there were no interactions between the MTHFR genotype and BET dose. In conclusion, BET supplementation may be beneficial for homocysteine concentration in healthy, physically active males, with no detrimental effect on lipid profile.

Colon Cancer Pharmacogenetics: A Narrative Review

Currently, metastatic colon cancer is treated with monotherapeutic regimens such as folinic acid, fluorouracil, and oxaliplatin (FOLFOX), capecitabine and oxaliplatin (CapeOX), and leucovorin, fluorouracil, and irinotecan hydrochloride (FOLFIRI). Other treatments include biological therapies and immunotherapy with drugs such as bevacizumab, panitumumab, cetuximab, and pembrolizumab. After the research, it was found that some mutations make those treatments not as effective in all patients. In this bibliographic review, we investigated the pharmacogenetic explanations for how mutations in the genes coding for rat sarcoma virus (RAS) and rapidly accelerated fibrosarcoma (RAF) reduce the effectiveness of these treatments and allow the continued proliferation of tumors. Furthermore, we note that patients with mutations in the dihydropyrimidine dehydrogenase (DPDY) gene usually require lower doses of therapies such as 5-fluorouracyl (5-FU) and capecitabine to avoid severe adverse effects. Some other mutations in the thymidylate synthase gene (TSYM), methylenetetrahydrofolate reductase gene (MTHFR), and ATP binding cassette transporter B (ABCB1 and ABCB2) affect efficacy and security of the treatments. It is important to address the clinical implication of the oncologist in the study of gene mutations than can influence in the antitumoral response and safety of colon cancer treatments.

Modulation of blood pressure regulatory genes in the Agtrap-Plod1 locus associated with a deletion in Clcn6

The AGTRAP-PLOD1 locus is a conserved gene cluster containing several blood pressure regulatory genes, including CLCN6, MTHFR, NPPA, and NPPB. Previous work revealed that knockout of Clcn6 on the Dahl Salt-Sensitive (SS) rat background (SS-Clcn6) resulted in lower diastolic blood pressure compared to SS-WT rats. Additionally, a recent study found sickle cell anemia patients with mutations in CLCN6 had improved survival and reduced stroke risk. We investigated whether loss of Clcn6 would delay the mortality of Dahl SS rats on an 8% NaCl (HS) diet. No significant difference in survival was found. The ability of Clcn6 to affect mRNA expression of nearby Mthfr, Nppa, and Nppb genes was also tested. On normal salt (0.4% NaCl, NS) diets, renal Mthfr mRNA and protein expression were significantly increased in the SS-Clcn6 rats. MTHFR reduces homocysteine to methionine, but no differences in circulating homocysteine levels were detected. Nppa mRNA levels in cardiac tissue from SS-Clcn6 rat in both normotensive and hypertensive conditions were significantly reduced compared to SS-WT. Nppb mRNA expression in SS-Clcn6 rats on a NS diet was also substantially decreased. Heightened Mthfr expression would be predicted to be protective; however, diminished Nppa and Nppb expression could be deleterious and by preventing or blunting vasodilation, natriuresis, and diuresis that ought to normally occur to offset blood pressure increases. The conserved nature of this genetic locus in humans and rats suggests more studies are warranted to understand how mutations in and around these genes may be influencing the expression of their neighbors.

Investigation of DPYD, MTHFR and TYMS polymorphisms on 5-fluorouracil related toxicities in colorectal cancer

Aim: To investigate the association of DPYD, MTHFR and TYMS polymorphisms on 5-fluorouracil (5-FU) related toxicities and patient survival. Materials & methods: A total of 103 colorectal cancer patients prescribed 5-FU were included in the study. Genotyping was conducted for several DPYD, MTHFR and TYMS polymorphisms using a microarray analyzer. Results: DPYD 496A>G polymorphism was found to be significantly associated with 5-FU related grade 0-2, but not severe toxicities (p = 0.02). Furthermore, patients with DPYD 85TC and CC genotypes had longer progression and overall survival times compared to TT genotypes in our study group (log rank = 6.60, p = 0.01 and log rank = 4.40, p = 0.04, respectively). Conclusion: According to our results, DPYD 496AG and GG genotypes might be protective against severe adverse events compared to the AA genotype. Another DPYD polymorphism, 85T>C, may be useful in colorectal cancer prognosis. Further studies for both polymorphisms should be conducted in larger populations to achieve accurate results.

SIRT1 pharmacological activation rescues vascular dysfunction and prevents thrombosis in MTHFR deficiency

Beyond well-assessed risk factors, cardiovascular events could be also associated with the presence of epigenetic and genetic alterations, such as the methylenetetrahydrofolate-reductase (MTHFR) C677T polymorphism. This gene variant is related to increased circulating levels of homocysteine (Hcy) and cardiovascular risk. However, heterozygous carriers have an augmented risk of cardiovascular accidents independently from normal Hcy levels, suggesting the presence of additional deregulated processes in MTHFR C677T carriers. Here, we hypothesize that targeting Sirtuin 1 (SIRT1) could be an alternative mechanism to control the cardiovascular risk associated to MTHFR deficiency condition. Flow Mediated Dilatation (FMD) and light transmission aggregometry assay were performed in subjects carrying MTHFR C677T allele after administration of resveratrol, the most powerful natural clinical usable compound that owns SIRT1 activating properties. MTHFR C677T carriers with normal Hcy levels revealed endothelial dysfunction and enhanced platelet aggregation associated with SIRT1 downregulation. SIRT1 activity stimulation by resveratrol intake was able to override these abnormalities without affecting Hcy levels. Impaired endothelial function, bleeding time, and wire-induced thrombus formation were rescued in a heterozygous Mthfr-deficient (Mthfr^+/–) mouse model after resveratrol treatment. Using a cell-based high-throughput multiplexed screening (HTS) assay, a novel selective synthetic SIRT1 activator, namely ISIDE11, was identified. Ex vivo and in vivo treatment of Mthfr^+/– mice with ISIDE11 rescues endothelial vasorelaxation and reduces wire-induced thrombus formation, effects that were abolished by SIRT1 inhibitor. Moreover, platelets from MTHFR C677T allele carriers treated with ISIDE11 showed normalization of their typical hyper-reactivity. These results candidate SIRT1 activation as a new therapeutic strategy to contain cardio and cerebrovascular events in MTHFR carriers.

Large-scale screening for factor V Leiden (G1691A), prothrombin (G20210A), and MTHFR (C677T) mutations in Greek population

Background and aims

To provide a fair estimate of the prevalence of factor V Leiden (FVL) (G1691A), prothrombin (G20210A), and MTHFR (C677T) mutations in the Greek population.

Methods

We genotyped a representative sample of 974 apparently healthy Greek adults by the method of real‐time PCR and we calculated the allele frequencies of factor V Leiden (FVL) (G1691A), prothrombin (G20210A), and MTHFR (C677T) mutations. In addition, we determined the frequency of co‐occurrence of FVL (1691A) and prothrombin (20210A), FVL (1691A) and MTHFR (677T), prothrombin (20210A) and MTHFR (677T) mutations.

Results

Τhe career frequencies of FVL (1691A), prothrombin (20210A), and MTHFR (677T) alleles were 7.5%, 4.5%, and 49.3% while the allele frequencies were 4%, 2.25%, and 39.5%, respectively. The coexistence of the allele frequencies combinations of two, FVL (1691A) and Prothrombin (20210A), FVL (1691A) and MTHFR (677T), prothrombin (20210A) and MTHFR (677T) was found in 1 (0.9%), 29 (3.5%), and 22 (3%) samples, respectively. Triple heterozygous carriers were not found.

Conclusion

Allele frequencies of the two (FVL and MTHFR) mutations are higher compared with published data. The large sample size of our study enhances the validity of our results and suggests a biological affinity of Greek population with Southern Italian populations.

Associations of Two Common Polymorphisms in MTHFR Gene with Blood Lipids and Therapeutic Efficacy of Simvastatin

BACKGROUND AND PURPOSE

Cardio-cerebrovascular disease is an important public health challenge worldwide, and its complex etiology has not been elucidated fully. The study was to investigate the relationship between two common polymorphisms C677T and A1298C in the methylenetetrahydrofolate reductase (MTHFR) gene, baseline lipids and the lipid-lowering efficacy of simvastatin in a Chinese hyperlipidemic population.

METHODS

All participants were recruited from Anhui, China. By the extreme sampling method, we selected subjects with low response (n=108) and high response (n=106) based on their adjusted lipid-lowering response to simvastatin administrated for 8 consecutive weeks. Both MTHFR C677T and A1298C loci were genotyped by MALDI-TOF MS platform. Serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were measured at baseline and after 8 weeks of oral 20 mg/d tablet of simvastatin.

RESULTS

Patients with the 677TT genotype had significantly higher baseline TC, HDL-C, and change in HDL-C (ΔHDL-C) levels after treatment than those with 677CC+CT genotypes (β = 0.207, P = 0.045; β = 0.182, P = 0.026; and β = 0.16, P = 0.002, respectively). Patients with 1298AC+CC genotypes had significantly higher baseline LDL-C and change in LDL-C (ΔLDL-C) levels (β = 0.276, P =0.043; β = 0.359, P = 0.025, respectively) than those with 1298AA genotype. We found statistical interactions between the two SNPs in association with baseline HDL-C (P for interaction = 0.034), TC (P for interaction = 0.069), and TG (P for interaction = 0.034). Baseline TC (P = 0.027) and HDL-C (P = 0.046) and change in HDL-C (P = 0.019) were different among those with the MTHFR A-T haplotype compared with A-C.

CONCLUSIONS

Our major findings suggest that both MTHFR C677T and A1298C polymorphisms could be important genetic determinants of lipid traits and drug efficacy of simvastatin. This will contribute to a better understanding of strategies for personalized medication in Chinese patients with dyslipidemia.

Methylene-tetrahydrofolate reductase gene C677T and A1298C polymorphisms as a risk factor for Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is a deadly viral disease. Methylene-tetrahydrofolate reductase (MTHFR) has an important role in folate metabolism, and also in the formation of new cells, DNA synthesis, repair and methylation. We aimed to examine the relationship between MTHFR gene C677T (Ala222Val, rs1801133) and A1298C (Glu429Ala, rs1801131) polymorphisms with CCHF in a Turkish population. Totally 273 participants were included in the current study. One hundred forty-one participants were CCHF patients and one hundred thirty-two participants were healthy controls. The polymerase chain reaction (PCR) and further restriction fragment length polymorphism (RFLP) assays were applied to determine the genotypes of MTHFR polymorphisms. We did not find any differences between the CCHF patients and healthy controls in terms of allele and genotype distributions of both the C677T and A1298C polymorphisms. In composite genotype analysis between different groups, the frequency of CT-AA composite genotype, which is formed by C677T-A1298C polymorphisms, was found to be significantly higher in Mild CCHF patients compared to both Severe CCHF patients and controls (p = 0.036 and p = 0.008, respectively). In conclusion, in this study, we found a relationship between CCHF and MTHFR gene polymorphisms. CT-AA composite genotype of MTHFR gene C677T and A1298C polymorphisms showed a predisposition to Mild CCHF.

Associations of plasma betaine, plasma choline, choline intake and MTHFR polymorphism (rs1801133) with anthropometric parameters of healthy adults are sex-dependent

OBJECTIVE

Choline and its metabolites seem to have relationships with body mass index (BMI), body fat, and body weight, but research results have proved inconsistent. We thus investigated the associations of plasma levels of TMAO, choline, and betaine, with anthropometric measurements, including modulatory effects of genetics and diet.

METHODS

The study was performed on a group of 421 adults aged 20 to 40, who had been recruited in Poland. Plasma concentrations of choline, betaine, and TMAO were determined using RP-UHPLC-ESI-MS. The following polymorphisms were genotyped using TaqMan probes: rs180113 (MTHFR), the rs70991108 (DHFR), rs2236225 (MTHFD1), and rs7946 and rs12325817 (PEMT). We employed multivariate linear regression to examine the associations between anthropometric measurements, one carbon metabolism metabolites, and genotypes.

RESULTS

Higher plasma choline was associated with higher BMI (β=0.17; p< 0.01), body weight (β=0.11; p< 0.05), body fat mass (β=0.10; p<0.05), and waist circumference (WC) (β=0.14; p<0.01), whereas higher choline intake was associated with lower body fat mass (β=-0.14; p< 0.01), and lower WC (β=-0.12; p<0.01). After stratification by sex, plasma betaine was found to be associated with BMI (β=-0.20; p<0.05) and body weight (β=-0.16; p<0.05) in men only, while choline intake was associated with body fat mass (β=-0.19; p<0.05), and WHR (β=-0.19; p<0.05), and MTHFR CC genotype was associated with WHR (β=0.15; p<0.05) in women only.

CONCLUSIONS

Higher plasma betaine and higher dietary choline are associated with lower fat mass and body weight, whereas higher plasma choline is positively associated with body weight status and adiposity. Moreover, these associations seem to be sex-specific. This article is protected by copyright. All rights reserved.

C677T Gene Polymorphism of MTHFR Is a Risk Factor for Impaired Renal Function in Pregnant Women With Preeclampsia in the Chinese Han Population

Impaired renal function in pregnant women with preeclampsia is particularly common, yet there is no consensus about implementation. This lack of consensus is due in part to uncertainty about risks for disease progression. Limited evidence suggests that C677T gene polymorphism of 5, 10-methylenetetrahydrofolate reductase (MTHFR C677T) may affect impaired renal function in pregnant women with preeclampsia in Chinese Han population. To investigate the association between MTHFR C677T and impaired renal function in pregnant women with preeclampsia, a total of 327 pregnant women diagnosed with gestational hypertension (GH) or preeclampsia-eclampsia (PE) from January 2016 to December 2021 were selected as the study subjects. The personal information, gestational information, clinical indicators, and the C677T gene polymorphism of MTHFR were tested. Compared with the GH group, the PE renal function impairment group had increased in blood pressure, homocysteine level, liver and kidney function indicators (creatinine, uric acid, urea nitrogen, cystatin C, alanine aminotransferase, aspartate aminotransferase, cholyglycine), and blood lipids (total cholesterol, triglycerides and low density lipoprotein) but had reductions in plasma protein (total protein, albumin, globulin, prealbumin), trace elements (calcium and zinc), prothrombin time and fibrinogen. The homocysteine level in the TT genotype was higher than that in the CC and CT genotypes. Binary logistic regression analysis showed that the MTHFR C677T gene polymorphism was associated with PE renal function impairment in the recessive model (OR: 1.620, 95% CI: 1.033-2.541, P < 0.05). These findings show that the C677T gene polymorphism of MTHFR is an independent risk factor for impaired renal function in pregnant Chinese Han women with PE.

Relationships between Maternal Gene Polymorphisms in One Carbon Metabolism and Adverse Pregnancy Outcomes: A Prospective Mother and Child Cohort Study in China

Background: To investigate relationships between five single nucleotide polymorphisms (SNP) in four maternal genes involved in one carbon metabolism and adverse pregnancy outcomes, including preterm birth (PTB), low birth weight (LBW), and small-for-gestational-age (SGA). Methods: This was a prospective mother and child cohort study in Wuqiang, China. Pregnant women (n = 939) were recruited from Jun 2016 to Oct 2018. Pregnancy outcomes (PTB, LBW, and SGA) were extracted from medical records and other information including age at childbearing, maternal education level, gravidity, parity, pre-pregnancy weight and height was collected by using a structured questionnaire. The maternal serum folate concentration was measured by using Abbott Architect i2000SR chemiluminescence analyzer in the first prenatal care visit. DNA genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase reductase (MTRR) A66G, methionine synthase (MTR) A2756G, and thymidylate synthetase (TYMS) rs3819102 was processed by Sequenom MassARRAY iPLEX Platform. Univariate and multivariate logistics regression analysis were used to test the relationships between 5 SNPs and PTB, LBW, SGA. Results: Totally, 849 dyads of women and infants were included in the analysis. The prevalence of PTD, LBW, and SGA were 3.76%, 1.58%, and 5.31% respectively. The homozygote frequencies of MTHFR C677T, MTHFR A1298C, MTRR A66G, MTR A2756G, and TYMS rs3819102 were 44.2%, 1.4%, 6.7%, 1.3%, and 3.2%, and the alt allele frequencies were 66.1%, 10.8%, 24.9%, 10.5%, and 20.5% respectively. The average serum folate concentration was 11.95 ng/mL and the folate deficiency rate was 0.47%. There were no significant associations between MTHFR C677T, MTHFR A1298C, MTRR A66G, MTR A2756G, TYMS rs3819102 alleles and PTD, LBW, SGA (p > 0.05). Conclusions: In the population with adequate folate status and low prevalence of adverse pregnancy outcomes, MTHFR C677T, MTHFR A1298C, MTRR A66G, MTR A2756G, TYMS rs3819102 alleles may not be related to PTD, LBW, and SGA.

Improved Retinal Microcirculation in Mild Diabetic Retinopathy Patients Carrying MTHFR Polymorphisms Who Received the Medical Food, Ocufolin®

Purpose

To evaluate the effects of Ocufolin® on retinal microcirculation in patients with mild diabetic retinopathy carrying MTHFR polymorphisms.

Methods

In a prospective, case-controlled study, eight patients with mild diabetic retinopathy and MTHFR polymorphisms and 15 normal controls (NC) were recruited. MTHFR polymorphisms were subtyped as normal, C677T, or A1298C. Best-corrected visual acuity (BCVA) was evaluated. Retinal blood flow velocity (BFV) was measured using Retinal Function Imager. Retinal tissue perfusion (RTP, blood flow rate per inner retinal volume) was calculated within a 2.5 mm diameter circle centered on the fovea. The eight retinopathy patients received Ocufolin® for 6 months, and their imaging was performed at baseline, 4 months, and 6 months. The NC group was imaged once.

Results

BCVA and vascular indices of DR + PM patients at baseline were below those of NC and improved after Ocufolin® administration. Compared to baseline, DR + PM patients had significantly improved BCVA during the follow-up period (P < 0.05). RTP and arteriolar BFV were significantly increased at 6 months (P < 0.05), approaching NC.

Conclusion

Ocufolin® may be effective in improving both visual acuity and retinal microcirculation in patients with DR + PM. Further studies with increasing sample size, and longer duration, including cases with severe DR, are needed.

Susceptibility of Genetic Variations in Methylation Pathway to Gastric Cancer

Background

DNA methylation in the CpG island is associated with gastric cancer, genetic variations residue in genes involved in methylation pathway could contribute to the occurrence of gastric cancer. Here, we investigated the association between DNMTs (DNMT1/DNMT3A/DNMT3B), MTHFR genetic variations and gastric cancer risk and patients' survival.

Patients and Methods

We recruited 490 gastric cancer patients and 488 age- and sex-matched healthy controls. The genotypes of the genetic variations were detected by a Mass-array platform. A commercial Helicobacter pylori (H. pylori) immunogold testing kit was used to determine the H. pylori infection.

Results

We found that carriers of DNMT1 rs2228612C allele was associated with decreased gastric cancer risk (CT vs. TT: adjusted OR = 0.70, 95% CI = 0.53-0.94, P = 0.02; CT/CC vs.TT: adjusted OR = 0.73, 95% CI = 0.56-0.96, P = 0.02). Further stratified analysis showed that DNMT1 rs2228612 CT/CC were associated with a decreased gastric cancer risk in the subgroups of age ≤64 years old (adjusted OR = 0.61, 95% CI = 0.41-0.90, P = 0.01), male (adjusted OR = 0.72, 95% CI = 0.53-0.98, P = 0.03), negative H. pylori infection (adjusted OR = 0.67, 95% CI = 0.45-0.98, P = 0.04), tumor stage T3-T4 (adjusted OR = 0.69, 95% CI = 0.51-0.92, P = 0.01), and non-gastric cardiac adenocarcinoma (NGCA) (adjusted OR = 0.72, 95% CI = 0.54-0.97, P = 0.03). However, none of the genetic variations of this study was associated with overall survival.

Conclusion

We concluded that the DNMT1 rs2228612C genotype is a protective factor for gastric cancer in Han Chinese population.

Associations of MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) Polymorphisms with Susceptibility to Bladder Cancer: A Systematic Review and Meta-Analysis

The effects of the MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) polymorphisms on bladder cancer risk have been evaluated in some studies. However, the results were conflicting and ambiguous. Therefore, we aimed to perform a comprehensive meta-analysis to investigate the association of these polymorphisms with risk of bladder cancer from all eligible case-control studies. PubMed, Web of science, Scopus, SID, CNKI and SciELO databases were searched to identify all relevant studies published up to 1 January, 2021. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of associations. A total of 20 case-control studies including 11 studies with 3463 cases and 3927 controls on MTHFR rs1801133 (677C>T) and 9 studies with 3177 cases and 3502 controls on rs180113 (1298A>C) polymorphism were selected. Pooled data revealed that the MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) polymorphisms were not associated with risk bladder cancer in overall. Stratified analysis by ethnicity revealed that the MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) polymorphisms were associated with bladder cancer risk in Asians, but not in Caucasians. There was no publication bias. The current meta-analysis revealed that the MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) polymorphisms were not risk factor for development of bladder cancer globally. However, large sample size, well-designed, and population-based studies should be performed to verify the association of the MTHFR polymorphisms with bladder cancer risk.

"Association of MTHFR and MS/MTR gene polymorphisms with congenital heart defects in North Indian population (Jammu and Kashmir): a case-control study encompassing meta-analysis and trial sequential analysis"

Background

The risk of Congenital Heart Defects (CHD) is greatly influenced by variants within the genes involved in folate-homocysteine metabolism. Polymorphism in MTHFR (C677T and G1793A) and MS/MTR (A2756G) genes increases the risk of developing CHD risk, but results are controversial. Therefore, we conducted a case–control association pilot study followed by an up-dated meta-analysis with trial sequential analysis (TSA) to obtain more precise estimate of the associations of these two gene variants with the CHD risk.

Methods

For case–control study, we enrolled 50 CHD patients and 100 unrelated healthy controls. Genotyping was done by PCR–RFLP method and meta-analysis was performed by MetaGenyo online Statistical Analysis System software. For meta-analysis total number of individuals was as follows: for MTHFR C677T 3450 CHD patients and 4447 controls whereas for MS A2756G 697 CHD patients and 777 controls.

Results

Results of the original pilot study suggested lack of association for MTHFR C677T and MS A2756G polymorphism with risk of CHD whereas MTHFR G1793A was significantly associated with the disease. On performing meta-analysis, a significant association was observed with MTHFR C677T polymorphism but not with MS A2756G. Trial sequential Analysis also confirmed the sufficient sample size requirement for findings of meta-analysis.

Conclusions

The results of the meta-analysis suggested a significant role of MTHFR in increased risk of CHD.

CRVO associated with COVID-19 and MTHFR mutation in a 15-year-old male

Purpose

To report a case of a central retinal vein occlusion (CRVO) associated with COVID-19 in a patient predisposed to clotting due to a genetic mutation in methylenetetrahydrofolate reductase (MTHFR).

Observations

A 15-year-old male presented with 1 day of painless blurry vision in the left eye. Exam disclosed trace anterior chamber cell, anterior vitreous cell, optic nerve head edema, temporally displaced macular star, dilated tortuous veins, and diffuse intraretinal hemorrhages. Exam and FA was consistent with CRVO, however the macular star and OCT were suggestive of a neuroretinitis.The patient then presented to a children's hospital for further evaluation. A routine screen for COVID-19 via nasopharyngeal swab was positive with a high viral load. He also had a known history of an MTHFR mutation. Extensive laboratory and neuroradiologic evaluation excluded other infectious, inflammatory, and coagulopathic etiologies.

Conclusions and Importance

This is a case of CRVO associated with COVID-19 infection and an underlying systemic hypercoagulable mutation, with an initial presentation that mimicked neuroretinitis. This case provides valuable diagnostic learning points and expands our knowledge of possible ocular complications of COVID-19.

Gene-Gene Interaction Study Between Genetic Polymorphisms of Folate Metabolism and MTR SNPs on Prognostic Features Impact for Breast Cancer

Background

Breast Cancer (BC), the second leading cause of cancer mortality after lung cancer and varied across the world due to genetic and environmental factors. In this study, we evaluated the interaction between the polymorphisms in genes encoding enzymes of folate metabolism: methylenetetrahydrofolate reductase (MTHFR), methionine synthesis reductase (MTR) with the BC prognostic factors.

Methods

This study was conducted on 160 Egyptian subjects, 60 controls and 100 cases. Sequencing, RFLP analysis in addition to statistical analysis including Chi-squared test, haplotype analysis was used to evaluate associations with BC risk and its clinicopathological parameters. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression.

Results

Strong significant association with breast cancer risk was observed for the haplotype (T-C-G) of MTHFR C677T/ MTHFR A1289C and MTRA2576G and hormonal receptor expression (ER-/PR-/HER2+), bigger and advanced tumor and metastatic lymph nodes. However, no significant difference was observed for age.

Conclusion

The combination of SNPs from MTHFR and MTR genes has a more synergistically genetic effect on BC disease progression. These SNPs could be used as tumor aggressiveness markers among Egyptian females with BC and could help in saving money and time.

Associations between Genetic Variants and Blood Biomarkers of One-Carbon Metabolism in Postmenopausal Women from the Women's Health Initiative Observational Study

BACKGROUND

Genetic variation in one-carbon metabolism may affect nutrient concentrations and biological functions. However, data on genetic variants associated with blood biomarkers of one-carbon metabolism in US postmenopausal women are limited, and whether these associations were affected by the nationwide folic acid (FA) fortification program is unclear.

OBJECTIVES

We investigated associations between genetic variants and biomarkers of one-carbon metabolism using data from the Women's Health Initiative Observational Study.

METHODS

In 1573 non-Hispanic White (NHW) and 282 Black/African American, American Indian/Alaska Native, Asian/Pacific Islander, and Hispanic/Latino women aged 50-79 y, 288 nonsynonymous and tagging single-nucleotide variants (SNVs) were genotyped. RBC folate, plasma folate, pyridoxal-5'-phosphate (PLP), vitamin B-12, homocysteine, and cysteine concentrations were determined in 12-h fasting blood. Multivariable linear regression tested associations per variant allele and for an aggregated genetic risk score. Effect modifications before, during, and after nationwide FA fortification were examined.

RESULTS

After correction for multiple comparisons, among NHW women, 5,10-methylenetetrahydrofolate reductase (MTHFR) rs1801133 (677C→T) variant T was associated with lower plasma folate (-13.0%; 95% CI: -17.3%, -8.6%) and higher plasma homocysteine (3.5%; 95% CI: 1.7%, 5.3%) concentrations. Other associations for nonsynonymous SNVs included DNMT3A rs11695471 (T→A) with plasma PLP; EHMT2 rs535586 (G→A), TCN2 rs1131603 (L349S A→G), and TCN2 rs35838082 (R188W G→A) with plasma vitamin B-12; CBS rs2851391 (G→A) with plasma homocysteine; and MTHFD1 rs2236224 (G→A) and rs2236225 (R653Q G→A) with plasma cysteine. The influence of FA fortification on the associations was limited. Highest compared with lowest quartiles of aggregated genetic risk scores from SNVs in MTHFR and MTRR were associated with 14.8% to 18.9% lower RBC folate concentrations. Gene-biomarker associations were similar in women of other races/ethnicities.

CONCLUSIONS

Our findings on genetic variants associated with several one-carbon metabolism biomarkers may help elucidate mechanisms of maintaining B vitamin status in postmenopausal women.

Folate metabolism abnormalities in infertile patients with endometriosis

Background: Homocysteine levels can be impacted by enzymes variations. Aim: To correlate MTHFR, MTR and MTRR variants with homocysteine levels in the blood and follicular fluid and assisted reproduction results. Material & methods: MTHFR (rs2274976, rs1801131, rs1801133), MTR (rs1805087) and MTRR (rs1801394) genotyping was performed by TaqMan assays and compared with homocysteine levels, measured by ELISA, to oocytes retrieved and to the pregnancy status of women with endometriosis and controls. Results: The MTR G allele and GG genotype were more common in patients with endometriosis. They also showed lower levels of homocysteine and more clinical gestations. Epistasis analysis showed a model associated with gestational results, composed of MTHFR+MTR variants (CC+AG). Conclusion: The summation effect of variants in genes participating in folate metabolism was associated with pregnancy status in Brazilian women. MTR variants were more observed in endometriosis patients, as well as lower follicular Hcy levels and increased clinical pregnancy results.

Association of MTHFR rs1801133 and homocysteine with Legg-Calvé-Perthes disease in Mexican patients

Background

Legg–Calvé–Perthes disease (LCPD) is the avascular osteonecrosis of the proximal femoral epiphysis. It is a rare disease of unclear etiology in children, although alterations in coagulation or the collagen gene have been described and could be associated with its etiology. Our objective was to evaluate the following alterations: COL1A1 (rs1107946, rs2412298), COL2A1 (rs121912891 and rs387106558), MTHFR rs1801133, CBS rs115742905, and PT rs1799963 and their relationship with LCPD.

Methods

DNA was obtained and genotyped by real-time PCR with TaqMan probes. Prothrombin (FII) and homocysteine (Hcy) were determined by a coagulometric method. The variables were described as mean and standard deviation or percentages, and genotypic and allelic distributions were analyzed using the Student's t-test. The Hardy–Weinberg equilibrium and OR were also used.

Results

We studied 23 patients with LCPD and 46 controls. We did not find any association of the MTHFR, CBS, PT, COL1A1, and COL2A1 genetic variants with LCPD. However, when adjusting the data with the Hcy values for the MTHFR C677T polymorphism, the C/C genotypes showed an association with the recessive model (p = 0.038), with susceptibility to LCPD.

Conclusion

No association was found with the CBS, PT, COL1A1, and COL2A1 genes. Nevertheless, our results suggest a significant link between moderately elevated Hcy levels and the MTHFR C677T polymorphism in a cohort of Mexican children with LCPD.

Maternal Risk Factors Triggering Congenital Heart Defects in Down Syndrome: A Case-Control Study

OBJECTIVES

Maternal MTHFR and MTRR polymorphisms as a risk of CHD in DS fetus were studied along with maternal folic acid supplementation, which could influence the folate metabolism along with other risk factors.

MATERIAL AND METHODS

A case-control study comprising of mothers of DS with and without CHD along with controls were recruited from a tertiary care center since 2018-2019. Genomic DNA was isolated followed by PCR-RFLP.

RESULTS

Mothers with age ≥35 years and having history of miscarriages have a higher risk of giving birth to DS with CHD (n = 35% and 42%, respectively). Mothers who carried the MTHFR 677CT/TT and MTRR 524CT/TT genotypes combination in the folic acid nonusers group during pregnancies had six-fold (OR = 6.909, p-value = 0.027; 95% CI-1.23 ± 38.51) and four-fold (OR = 4.75, p-value = 0.040; 95% CI-1.067 ± 21.44) increased odds of having a DS child with CHD, respectively, as compared to folic acid users.

CONCLUSION

Maternal age, folic acid supplementation, and previous history of miscarriages is involved in the etiology of CHD in DS fetus in Indian population. Maternal MTHFR and MTRR polymorphisms are also involved in the occurrence of CHD and DS in Indian population when controlling for periconceptional folic acid supplementation.

LIMITATIONS

Single-Centered Study.

Effect of Polymorphisms of ABCB1 and MTHFR on Methotrexate-Related Toxicities in Adults With Hematological Malignancies

Study of the association between single nucleotide polymorphisms (SNPs) of methotrexate (MTX) pathway genes and MTX-related toxicity in the treatment of hematological malignancies is popular. Here, we studied the association between SNPs of MTHFR and ABCB1 and MTX-related toxicity in 157 adult Chinese patients diagnosed with hematological malignancies. Patients were genotyped for MTHFR rs1801131, MTHFR rs1801133, and ABCB1 rs1045642 by fluorescence in situ hybridization. Patients with MTHFR rs1801133T allele had a significantly higher risk of hematopoietic toxicity compared with those with CC genotype (p=0.003). With respect to MTHFR rs1801131, patients with CC and AC genotypes had significantly lower frequency of hematopoietic toxicity than patients with AA genotype (p=0.044). In conclusion, we identified an important influence of the SNPs of ABCB1 and MTHFR on MTX-related hematopoietic toxicity in adults with hematological malignancies. To optimize high-dose (HD)-MTX therapy and reduce related hematopoietic toxicity, it is necessary to detect the SNPs of MTHFR and ABCB1 before initiating HD-MTX and deciding the optimal dose of MTX and duration of leucovorin rescue, according to genetic tests and disease type in adults with hematological malignancies.

Associations between AGT, MTHFR, and VEGF gene polymorphisms and preeclampsia in the Chinese population

INTRODUCTION

Preeclampsia (PE) is a pregnancy-specific multisystemic syndrome. This study aimed to investigate the associations between angiotensinogen (AGT), methylenetetrahydrofolate reductase (MTHFR), vascular endothelial growth factor (VEGF) polymorphisms, and PE in the Han Chinese population.

METHODS

We genotyped 26 single-nucleotide polymorphisms (SNP) in three genes by using QuantStudio™ 12 K Flex Real-Time PCR technology in 168 patients with PE and 204 healthy pregnant control subjects. The associations of tested polymorphisms with PE were analyzed at allele, genotype, and haplotype levels.

RESULTS

A common coding variant in MTHFR, rs2274976, was significantly associated with increased risk of PE in both allelic and genotype models (P < 0.05). The heterozygous genotypes of rs699 (G/A vs G/G) in AGT gene and rs3025035 (C/T vs C/C) in VEGF gene showed weak associations with increased PE risk, whereas the mutant homozygous genotype of rs3024987 (TT vs C/C) and the heterozygous genotype of rs3025039 (C/T vs C/C) in VEGF gene displayed weak associations with decreased PE risk (P < 0.05).

DISCUSSION

However, these weak associations lost significance after multiple testing correction. The results indicated that rs2274976 in MTHFR gene may contribute to the increased risk of PE in pregnant women. AGT and VEGF gene polymorphisms may not play a significant role in PE development.

Association of Novel Single Nucleotide Polymorphisms of Genes Involved in Cell Functions with Male Infertility: A Study of Male Cases in Northwest Iran

Background

Infertility is a global health problem caused by various environmental and genetic factors. Male infertility accounts for 40-50% of all cases of infertility and approximately half of them are grouped as idiopathic with no definitive causes. Previous studies have suggested an association between some SNPs and infertility in men. In this study, an attempt was made to investigate the association of 7 different SNPs of 4 genes involved in common cell functions with male infertility.

Methods

MTHFR rs1801131 (T>G), MTHFR rs2274976 (G>A), FASLG rs80358238 (A>G), FASLG rs12079514 (A>C), GSTM1 rs1192077068 (G>A), BRCA2 rs4987117 (C>T), and BRCA2 rs11571833 (A>T) were genotyped in 120 infertile men with idiopathic azoospermia or severe oligospermia and 120 proven fertile controls using ARMS-PCR methods. Next, 30% of SNPs were regenotyped to confirm the results. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using SPSS statistical software to evaluate the strength of association. The p<0.05 were considered statistically significant.

Results

Statistical analysis revealed significant association between MTHFR rs-2274976 AA variant (OR: 10.00, CI: 3.203-31.225), FASLG rs12079514 AC variant (OR: 0.412, CI: 0.212-0.800), and BRCA2 rs11571833 TT variant OR: 6.233, CI: 3.211-12.101) with male infertility, but there was no significant difference between case and control groups in MTHFR rs1801131 (p= 0.111), GSTM1 rs1192077068 (p=0.272), BRCA2 rs4987117 (p=0.221), and FASLG rs80358238 (p=0.161).

Conclusion

Our findings suggested that some novel polymorphisms including MTHFR rs2274976, FASLG rs12079514, and BRCA2 rs11571833 might be the possible predisposing risk factors for male infertility in cases with idiopathic azoospermia.

MTHFR Polymorphism Is Associated With Severe Methotrexate-Induced Toxicity in Osteosarcoma Treatment

Background

Previous studies have revealed the critical role of methylene tetrahydrofolate reductase (MTHFR) polymorphisms in response to high-dose methotrexate (MTX)-induced toxicity in osteosarcoma patients. However, the conclusions remain controversial. In this setting, we performed a meta-analysis to determine their association more precisely.

Method

Eligible studies were searched and screened in PubMed, Web of Science, Cochrane Library, Clinical-Trials.gov, Embase, and China National Knowledge Infrastructure (CNKI) following specific inclusion and exclusion criteria. The required information was retrieved and collected for subsequent meta-analysis. Association between MTHFR polymorphism and MTX toxicity was evaluated by odds ratios (ORs).

Results

Seven studies containing 585 patients were enrolled and analyzed in this meta-analysis. Overall, the MTX related grade 3-4 liver toxicity was significantly associated with MTHFR rs1801133 allele (T vs. C: OR=1.61, 95%CI=1.07-2.42, P=0.024), homozygote (TT vs. CC: OR=2.11, 95%CI=1.06-4.21, P=0.011), and dominant genetic model (TT/TC vs. CC: OR=3.15, 95%CI=1.30-7.60, P=0.035) in Asian population. Meanwhile, close associations between MTX mediated grade 3-4 mucositis and MTHFR rs1801133 polymorphism were identified in allele contrast (T vs. C: OR=2.28, 95%CI=1.49-3.50, P<0.001), homozygote comparison (TT vs. CC: OR=4.07, 95%CI=1.76-9.38, P=0.001), heterozygote comparison (TC vs. CC: OR=2.55, 95%CI=1.20-5.42, P=0.015), recessive genetic model (TT vs. TC/CC: OR=2.09, 95%CI=1.19-3.67, P=0.010), and dominant genetic model (TT/TC vs. CC: OR=2.97, 95%CI=1.48-5.96, P=0.002). Additionally, kidney toxicity was corelated with the heterozygote comparison (TC vs. CC: OR=2.63, 95%CI=1.31-5.29, P=0.007) of rs1801133 polymorphism.

Conclusion

The MTHFR rs1801133 polymorphism was significantly associated with severer liver toxicity induced by high-dose MTX treatment in the Asian population. In the meantime, patients with MTHFR rs1801133 polymorphism were predisposed to MTX- related mucositis.

Relation Between Methylenetetrahydrofolate Reductase Polymorphisms (C677T and A1298C) and Migraine Susceptibility

Migraine is a neurological disorder which impairs the patient's quality of life. Several association studies investigating the association between MTHFR gene C677T and A1298C polymorphisms and susceptibility to migraine were published. But the results were conflicting, so authors performed a meta-analysis of published case control studies to find out the exact association between MTHFR polymorphism and migraine susceptibility. Four databases were searched for suitable studies up to December, 2018. Odds ratios (OR) with 95% confidence intervals (CI) was calculated adopting additive, homozygote, co-dominant, dominant, and recessive genetic models. Results of MTHFR C677T polymorphism studies meta-analysis showed significant association with migraine risk using allele contrast, homozygote, dominant and recessive genetic models (T vs. C: OR = 1.18, 95% CI = 1.00-1.26, p = 0.05; TT vs. CC: OR = 1.24, 95% CI = 1.0-1.5, p = 0.04; CT vs. CC: OR = 1.08, 95% CI = 0.97-1.07, p = 0.25; TT + CT vs. CC: OR = 1.15, 95% CI = 1.0-1.29, p = 0.04; TT vs. CT + CC: OR = 1.97, 95% CI = 1.28-3.42, p = 0.002). However, results of MTHFR A1298 polymorphism studies meta-analysis did not show any association with migraine. Subgroup analysis based on ethnicity and migraine types i.e. migraine with aura (MA) and without aura (MO) were also performed. Results of present meta-analysis indicate overall association between MTHFR C677T polymorphism with migraine in total 24 studies, in Asian population and in MA cases but did not show any association with Caucasian population and MO cases.

Hyperhomocysteinemia and Dementia Associated With Severe Cortical Atrophy, but No Amyloid Burden

We report a case of a 77 years old patient who was admitted to our memory clinic because of progressive gait impairment and amnestic cognitive decline associated with extrapyramidal symptoms and behavioral changes. The clinical picture was consistent with a possible diagnosis of Alzheimer's Disease associated with parkinsonian symptoms or with a Parkinson Plus syndrome. After a complete investigation, she was found to have a high plasma level of homocysteine due to homozygous methylene-tetrahydrofolate reductase (MTHFR) gene C665 T polymorphism, cognitive and motor impairment were associated with a severe cortical atrophy and mild subcortical vascular disease. PET neuroimaging excluded a significant amyloid load. Clinically, she showed improvement of the movement disorder and functional status after folate integration plus levodopa and memantine administration. We concluded for a primary degenerative dementia with movement impairment associated with persistent hyperhomocysteinemia. We hypothesized that neurodegeneration is driven by mechanisms linked to homocysteine metabolism possibly associated with tauopathy.

Methylenetetrahydrofolate (MTHFR), the One-Carbon Cycle, and Cardiovascular Risks

The 5-10-methylenetetrahydrofolate reductase (MTHFR) enzyme is vital for cellular homeostasis due to its key functions in the one-carbon cycle, which include methionine and folate metabolism and protein, DNA, and RNA synthesis. The enzyme is responsible for maintaining methionine and homocysteine (Hcy) balance to prevent cellular dysfunction. Polymorphisms in the MTHFR gene, especially C677T, have been associated with various diseases, including cardiovascular diseases (CVDs), cancer, inflammatory conditions, diabetes, and vascular disorders. The C677T MTHFR polymorphism is thought to be the most common cause of elevated Hcy levels, which is considered an independent risk factor for CVD. This polymorphism results in an amino acid change from alanine to valine, which prevents optimal functioning of the enzyme at temperatures above 37 °C. Many studies have been conducted to determine whether there is an association between the C677T polymorphism and increased risk for CVD. There is much evidence in favour of this association, while several studies have concluded that the polymorphism cannot be used to predict CVD development or progression. This review discusses current research regarding the C677T polymorphism and its relationship with CVD, inflammation, diabetes, and epigenetic regulation and compares the evidence provided for and against the association with CVD.

Association Between MTHFR Polymorphisms and the Risk of Essential Hypertension: An Updated Meta-analysis

BACKGROUND

Since the 1990s, there have been a lot of research on single-nucleotide polymorphism (SNP) and different diseases, including many studies on 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphism and essential hypertension (EH). Nevertheless, their conclusions were controversial. So far, six previous meta-analyses discussed the internal relationship between the MTHFR polymorphism and EH, respectively. However, they did not evaluate the credibility of the positive associations. To build on previous meta-analyses, we updated the literature by including previously included papers as well as nine new articles, improved the inclusion criteria by also considering the quality of the papers, and applied new statistical techniques to assess the observed associations.

OBJECTIVES

This study aims to explore the degree of risk correlation between two MTHFR polymorphisms and EH.

METHODS

PubMed, EMBASE, the Cochrane Library, CNKI, and Wan Fang electronic databases were searched to identify relevant studies. We evaluated the relation between the MTHFR C677T (rs1801133) and A1298C (rs1801131) polymorphisms and EH by calculating the odds ratios (OR) as well as 95% confidence intervals (CI). Here we used subgroup analysis, sensitivity analysis, cumulative meta-analysis, assessment of publication bias, meta-regression meta, False-positive report probability (FPRP), Bayesian false discovery probability (BFDP), and Venice criterion.

RESULTS

Overall, harboring the variant of MTHFR C677T was associated with an increased risk of EH in the overall populations, East Asians, Southeast Asians, South Asians, Caucasians/Europeans, and Africans. After the sensitivity analysis, positive results were found only in the overall population (TT vs. CC: OR = 1.14, 95% CI: 1.00-1.30, P _h = 0.032, I ² = 39.8%; TT + TC vs. CC: OR = 1.15, 95% CI: 1.01-1.29, P _h = 0.040, I ² = 38.1%; T vs. C: OR = 1.14, 95% CI: 1.04-1.25, P _h = 0.005, I ² = 50.2%) and Asian population (TC vs. CC: OR = 1.14, 95% CI: 1.01-1.28, P _h = 0.265, I ² = 16.8%; TT + TC vs. CC: OR = 1.17, 95% CI: 1.04-1.30, P _h = 0.105, I ² = 32.9%; T vs. C: OR = 1.10, 95% CI: 1.02-1.19, P _h = 0.018, I ² = 48.6%). However, after further statistical assessment by FPRP, BFDP, and Venice criteria, the positive associations reported here could be deemed to be false-positives and present only weak evidence for a causal relationship. In addition, when we performed pooled analysis and sensitivity analysis on MTHFR A1298C; all the results were negative.

CONCLUSION

The positive relationships between MTHFR C677T and A1298C polymorphisms with the susceptibility to present with hypertension were not robust enough to withstand statistical interrogation by FPRP, BFDP, and Venice criteria. Therefore, these SNPs are probably not important in EH etiology.

Isolation-Induced Ultrasonic Vocalization in Environmental and Genetic Mice Models of Autism

Studies in rodent models suggest that calls emitted by isolated pups serve as an early behavioral manifestation of communication deficits and autistic like behavior. Previous studies in our labs showed that gestational exposure to the pesticide chlorpyrifos (CPF) and the Mthfr-knock-out mice are associated with impaired social preference and restricted or repetitive behavior. To extend these studies, we examine how pup communication via ultrasonic vocalizations is altered in these ASD models. We implemented an unsupervised hierarchical clustering method based on the spectral properties of the syllables in order to exploit syllable classification to homogeneous categories while avoiding over-categorization. Comparative exploration of the spectral and temporal aspects of syllables emitted by pups in two ASD models point to the following: (1) Most clusters showed a significant effect of the ASD factor on the start and end frequencies and bandwidth and (2) The highest percent change due to the ASD factor was on the bandwidth and duration. In addition, we found sex differences in the spectral and temporal properties of the calls in both control groups as well as an interaction between sex and the gene/environment factor. Considering the basal differences in the characteristics of syllables emitted by pups of the C57Bl/6 and Balb/c strains used as a background in the two models, we suggest that the above spectral-temporal parameters start frequency, bandwidth, and duration are the most sensitive USV features that may represent developmental changes in ASD models.

Association of MTHFR 677C > T, 1298A > C and MTR 2756A > G Polymorphisms with Susceptibility to Childhood Retinoblastoma: A Systematic Review and Met-Analysis

BackgroundRecently, epidemiological studies investigating the association of MTHFR 677 C > T, 1298 A > C and MTR 2756 A > G polymorphism with retinoblastoma susceptibility reported controversial results. Methods: Data were collected from several electronic databases such as PubMed, EMBASE, and Google Scholar databases, with the last search up to December 05, 2019. Results: A total of eleven case-control studies including four studies with 324 cases and 490 controls on MTHFR 677 C > T, four studies with 324 cases and 490 controls on MTHFR 1298 A > C, and three studies with 283 cases and 485 controls on MTR 2756 A > G were selected. There was a significant association between MTHFR 677 C > T and MTR 2756 A > G polymorphisms and an increased risk of retinoblastoma. However, MTHFR 1298 A > C polymorphism was not significantly associated with risk of retinoblastoma. Conclusion: This meta-analysis demonstrated that MTHFR 677 C > T and MTR 2756 A > G polymorphisms might play important roles in the development of retinoblastoma. No association with MTHFR 1298 A > C polymorphism was observed.

5-Methyltetrahydrofolate and Vitamin B12 Supplementation Is Associated with Clinical Pregnancy and Live Birth in Women Undergoing Assisted Reproductive Technology

The homocysteine pathway in the preconception period should be evaluated to highlight micronutrient deficiencies and warrants optimal multivitamin supplementation, before Assisted Reproduction, as preconception care. We conducted a retrospective study aimed at investigating the role of vitamin B complex (5-methyltetrahydrofolate, vitamin B12, vitamin B6) supplement use compared with the role of only folic acid supplement use, in relation to clinical pregnancy and live birth in infertile women undergoing homologous ART. We investigated 269 Caucasian women referred to the Centre for Assisted Reproductive Technology for homologous ART. In these women, 111 (Group A) were daily supplemented with vitamin B complex and 158 (Group B) with only folic acid. In group A the mean number of Metaphase II oocytes and the 2PN Fertilization Rate were higher in comparison to group A (p = 0.04; p = 0.05, respectively). A higher percentage of women in group A had a clinical pregnancy and live birth in comparison to group B (p = 0.01; p = 0.02, respectively). Vitamin B complex supplementation remained independently associated, after multivariable adjustment, with clinical pregnancy (OR 2.03, p = 0.008) and live birth (OR 1.83, p = 0.03). Women supplemented with 5-MTHF and vitamin B12, have a higher chance of clinical pregnancy and live birth in comparison to those supplemented with only folic acid.

The MCP-1 rs1024611 and MTHFR rs1801133 gene variations and expressions in alopecia areata: A pilot study

Background

Monocyte chemoattractant protein‐1 (MCP‐1) is highly expressed by lymphocytes at skin sites affected by alopecia areata (AA). Variations in MCP‐1 as well as in methylene‐tetrahydrofolate reductase (MTHFR), a key enzyme related to many inflammatory pathologies, have been associated with several autoimmune disorders. This study was designed to test a possible association between MCP‐1 and MTHFR variations and altered expression of their genes and the risk of AA.

Methods

Blood samples of patients (60) suffering from AA as well as healthy subjects (60) were collected. Gene expression levels of MCP‐1 and MTHFR were evaluated by real‐time reverse‐transcription polymerase chain reaction analysis. Moreover, MCP‐1 rs1024611 (A‐2518G) and MTHFR rs1801133 (C677T) polymorphisms were genotyped by using polymerase chain reaction‐restriction fragment length polymorphism assays.

Results

In contrast to MCP‐1, the MTHFR gene expression was found to be significantly higher in patients than in controls. Further stratification of the patients revealed that polymorphic genotypes in MCP‐1 (AG + GG) and MTHFR (CT + TT) could significantly alter gene expression levels. Elevation of MCP‐1 expression was significantly associated with the total number of variant MCP‐1 and MTHFR alleles. However, no statistically significant difference was noticed in the genotypic distribution of MCP‐1 and MTHFR variations between patients and controls.

Conclusion

In summary, despite MCP‐1 rs1024611 and MTHFR rs1801133 variations are not associated with AA risk, they may implicate the disease pathogenesis by influencing MCP‐1 activity.

MEDTEC Students against Coronavirus: Investigating the Role of Hemostatic Genes in the Predisposition to COVID-19 Severity

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of the coronavirus disease 2019 (COVID-19) pandemic. Besides virus intrinsic characteristics, the host genetic makeup is predicted to account for the extreme clinical heterogeneity of the disease, which is characterized, among other manifestations, by a derangement of hemostasis associated with thromboembolic events. To date, large-scale studies confirmed that genetic predisposition plays a role in COVID-19 severity, pinpointing several susceptibility genes, often characterized by immunologic functions. With these premises, we performed an association study of common variants in 32 hemostatic genes with COVID-19 severity. We investigated 49,845 single-nucleotide polymorphism in a cohort of 332 Italian severe COVID-19 patients and 1668 controls from the general population. The study was conducted engaging a class of students attending the second year of the MEDTEC school (a six-year program, held in collaboration between Humanitas University and the Politecnico of Milan, allowing students to gain an MD in Medicine and a Bachelor’s Degree in Biomedical Engineering). Thanks to their willingness to participate in the fight against the pandemic, we evidenced several suggestive hits (p < 0.001), involving the PROC, MTHFR, MTR, ADAMTS13, and THBS2 genes (top signal in PROC: chr2:127192625:G:A, OR = 2.23, 95%CI = 1.50–3.34, p = 8.77 × 10⁻⁵). The top signals in PROC, MTHFR, MTR, ADAMTS13 were instrumental for the construction of a polygenic risk score, whose distribution was significantly different between cases and controls (p = 1.62 × 10⁻⁸ for difference in median levels). Finally, a meta-analysis performed using data from the Regeneron database confirmed the contribution of the MTHFR variant chr1:11753033:G:A to the predisposition to severe COVID-19 (pooled OR = 1.21, 95%CI = 1.09–1.33, p = 4.34 × 10⁻¹⁴ in the weighted analysis).