Dynamic inter-domain transformations mediate the allosteric regulation of human 5, 10-methylenetetrahydrofolate reductase.

5,10-methylenetetrahydrofolate reductase (MTHFR) commits folate-derived one-carbon units to generate the methyl-donor S-adenosyl-L-methionine (SAM). Eukaryotic MTHFR appends to the well-conserved catalytic domain (CD) a unique regulatory domain (RD) that confers feedback inhibition by SAM. Here we determine the cryo-electron microscopy structures of human MTHFR bound to SAM and its demethylated product S-adenosyl-L-homocysteine (SAH). In the active state, with the RD bound to a single SAH, the CD is flexible and exposes its active site for catalysis. However, in the inhibited state the RD pocket is remodelled, exposing a second SAM-binding site that was previously occluded. Dual-SAM bound MTHFR demonstrates a substantially rearranged inter-domain linker that reorients the CD, inserts a loop into the active site, positions Tyr404 to bind the cofactor FAD, and blocks substrate access. Our data therefore explain the long-distance regulatory mechanism of MTHFR inhibition, underpinned by the transition between dual-SAM and single-SAH binding in response to cellular methylation status.

MTHFR and MTRR gene polymorphisms in patients with chronic hepatitis B virus infections in Zigong, Sichuan Province.

BACKGROUND: Chronic hepatitis B virus (HBV) infection is a severe disease affecting the physical and economic well-being of patients. The relationship between polymorphisms in the MTHFR gene and disease progression following HBV infection remains a controversial topic. AIM: To study MTHFR and MTRR gene polymorphisms in patients with chronic HBV infections in Zigong, Sichuan Province. SUBJECTS AND METHODS: One hundred and ninety-one patients with chronic HBV infections were divided into three groups: the chronic hepatitis B (CHB) group (n = 71), the hepatitis B-induced liver cirrhosis (LC) group (n = 56), and the hepatitis B-related primary liver cancer (PLC) group (n = 64). The gene polymorphisms were detected using the PCR-melt curve method and analysed. RESULTS: The distributions of MTHFR C677T (CC: 41.2% vs. 41.8%; CT: 50% vs. 45.5%; TT: 8.8% vs. 12.7%; p = 0.714), MTHFR A1298C (AA: 70.6% vs. 72.7%; AC: 26.5% vs. 25.5%; CC: 2.9% vs. 1.8%; p = 1.000), and MTRR A66G (AA: 58.1% vs. 65.5%; AG: 39.0% vs. 29.1%; 2.9% vs. 5.5%; p = 0.353) genetic polymorphisms did not vary between male and female patients from Zigong. In addition, there were no differences in the distributions of MTHFR C677T (CC: 43.4% vs. 38.8%; CT: 49.1% vs. 48.2%; TT: 7.5% vs. 12.9%; p = 0.444), MTHFR A1298C (AA: 76.4% vs. 64.7%; AC: 20.8% vs. 32.9%; CC: 2.8% vs. 2.4%; p = 0.155), and MTRR A66G (AA: 62.3% vs. 57.6%; AG: 34.0% vs. 38.8%; 3.8% vs. 3.5%; p = 0.353) genetic polymorphisms between the patients <60 and >60 years of age. The distributions of MTHFR C677T (CHB vs. LC, p = 0.888; CHB vs. PLC, p = 0.661; PLC vs. LC, p = 0.926), MTHFR A1298C (CHB vs. LC, p = 0.12; CHB vs. PLC, p = 0.263; PLC vs. LC, p = 0.550), and MTRR A66G (CHB vs. LC, p = 0.955; CHB vs. PLC, p = 0.645; PLC vs. LC, p = 0.355) gene polymorphisms were comparable between the CHB, LC, and PLC groups. CONCLUSION: The distributions of MTHFR and MRRR genetic polymorphisms in the population with HBV infections in Zigong, Sichuan Province did not differ in age and sex. The MTHFR and MRRR genetic polymorphisms were comparable between the CHB, LC, and PLC groups.

Thrombophilia genetic mutations and their relation to disease severity among patients with COVID-19.

OBJECTIVES: Patients with COVID-19 infection appear to develop virus-induced hypercoagulability resulting in numerous thrombotic events. The aim of the present study was to determine the relationship between the thrombophilia genes mutations (prothrombin G20210A, factor V Leiden, and methyltetrahydrofolate reductase (MTHFR)) and the severity of COVID-19 patients. DESIGN: Prospective cross-sectional study. METHOD: One hundred and forty patients (80 adults and 60 children) were included in the current study. They were divided into the severe COVID-19 group and the mild COVID-19 group, with each group comprising 40 adults and 30 children. The patients were assessed for FV R506Q, FV R2H1299R, MTHFR A1298C, MTHFR C677T, and prothrombin gene G20210A polymorphisms. CBC, D-dimer, renal and liver function tests, hs-CRP, ferritin, and LDH were also assessed. Thrombotic events were clinically and radiologically documented. RESULTS: Severe COVID-19 cases were significantly more frequent to have a heterozygous mutation for all the studied genes compared to mild COVID-19 cases (p<0.05 for all). Being mutant to gene FV R506Q carried the highest risk of developing a severe disease course (p<0.0001). Patients with abnormally high D-dimer levels were significantly more frequent to be heterozygous for FV R506Q, FV R2H1299R, and prothrombin gene G20210A (p = 0.006, 0.007, and 0.02, respectively). CONCLUSION: We concluded that there is an evident relationship between severe COVID-19 and inherited thrombophilia. In the current study, FV R506Q gene mutation carried the highest risk of developing a severe COVID-19 disease course.

[Analysis of 9 patients with adolescence-onset methylenetetrahydrofolate reductase deficiency].

Objective: To explore the diagnosis and treatment of adolescence-onset methylenetetrahydrofolate reductase (MTHFR) deficiency. Methods: This was a retrospective case study. Nine patients with adolescence-onset MTHFR deficiency were diagnosed at Peking University First Hospital from January 2016 to December 2022, and followed up for more than 1 year. Their general information, clinical manifestations, laboratory tests, cranial images, MTHFR gene variants, diagnosis, treatment, and outcome were analyzed retrospectively. Results: The 9 patients came from 8 families. They had symptoms at age of 8.0 years to 17.0 years and diagnosed at 9.0 years to 17.5 years. Eight were male and 1 was female. Two patients were brothers, the elder brother developed abnormal gait at 17.0 years; and the younger brother was then diagnosed at 15.0 years of age and treated at the asymptomatic stage, who was 18.0 years old with normal condition during this study. The main manifestations of the 8 symptomatic patients included progressive dyskinesia and spastic paralysis of the lower limbs, with or without intellectual decline, cognitive impairment and behavioral abnormalities. Totally, 15 variants of MTHFR gene were identified in the 9 patients, including 8 novel variants. Five patients had brain image abnormalities. Increased plasma total homocysteine level (65-221 µmol/L) was found in all patients, and decreased to 20-70 µmol/L after treatment with betaine and calcium folinate. Besides, the 8 symptomatic patients had their behavior and cognitive problems significantly improved, with a legacy of lower limb motor disorders. Conclusions: Late-onset MTHFR deficiency can occur in adolescence. The diagnosis is usually delayed because of non-specific clinical symptoms. The test of blood total homocysteine could be used as a selective screening test. Eight novel varients of MTHFR gene were identified. Timely treatment can improve clinical condition significantly, and pre-symptomatic treatment may prevent brain damage.

Interaction effects of MTHFR C677T and A1298C polymorphisms with maternal glycated haemoglobin levels on adverse birth outcomes.

AIMS: The role of maternal genetic factors in the association between high glycated haemoglobin (HbA1c) levels and adverse birth outcomes remains unclear. MATERIALS AND METHODS: In this study, the maternal HbA1c levels of 5108 normoglycemic pregnant women in China were measured, and A1298C and C677T polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene were genotyped. RESULTS: Elevated HbA1c levels during the second trimester were associated with increased risks of macrosomia, large-for-gestational age (LGA), preterm birth (PTB), and reduced gestational age (p < 0.05). Pregnant women with MTHFR A1298C AA or C677T CT + TT genotypes were susceptible to adverse pregnancy outcomes related to HbA1c levels. Among pregnant women with the A1298C AA genotype, each standard deviation (SD) increase in HbA1c levels increased the risk of PTB by 1.32-times and reduced the gestational age by 0.11 weeks (p < 0.05). For MTHFR C677T CC + TT genotype carriers, higher HbA1c levels were associated with 1.49-, 1.24-, and 1.23-times increased risks of macrosomia, LGA, and PTB, respectively (p < 0.05). A U-shaped curve for PTB risk in relation to HbA1c levels was observed among the C677T CC + TT participants, with a cut-off value of 4.58%. Among subjects with the A1298C AA genotype combined with the C677T CT + TT genotype, each SD increase in HbA1c levels was associated with 1.40 and 1.37-times increased risks of LGA and PTB, respectively. CONCLUSIONS: Our findings highlight the importance of glycaemic control during pregnancy and the potential impact of genetic factors on birth outcomes. However, further large-scale studies are required to confirm these findings.

The effects of genetic polymorphism on toxicity and pharmacokinetics of methotrexate in Egyptian adult patients with leukaemia or lymphoma.

Polymorphisms in genes coding folate-metabolising enzymes might alter the pharmacokinetics and sensitivity for methotrexate "MTX".The aim of the study aimed to investigate the influence of MTHFR C677T, DHFR19 Ins/del, GGH -401 C > T, and MTR A2756G polymorphisms on MTX toxicity and pharmacokinetics in Egyptian patients with Acute lymphoblastic leukaemia (ALL) or Non-Hodgkin lymphoma (NHL).Fifty adult Egyptian patients with ALL and NHL, treated with high dose MTX, were prospectively enrolled in the study. Clinical and biochemical data was collected objectively from medical records after each cycle of MTX. Plasma concentrations of MTX were measured after 72 h of initiation of infusion. Genotyping was done with a PCR-ARMS and PCR-RFLP assays.The MTHFR C677T T variants significantly increased the risk of leukopoenia, whereas the genotype MTHFR 677 C > T TT significantly associated with lymphocytopenia, thrombocytopenia, and anaemia. The genotype GGH-401 TT was significantly correlated with anaemia. Plasma MTX level was significantly higher in patients with MTR A2756G G variants.MTHFR polymorphism played the main role in MTX toxicities. The pharmacokinetics of MTX was affected by MTR polymorphism. GGH mutation was mainly concerned with anaemia. Pharmacogenetic testing are recommended to optimise MTX therapy.

Sperm DNA methylation defects in a new mouse model of the 5,10-methylenetetrahydrofolate reductase 677C>T variant and correction with moderate dose folic acid supplementation.

5,10-Methylenetetrahydrofolate reductase (MTHFR) is an enzyme that plays a key role in providing methyl groups for DNA methylation, including during spermatogenesis. A common genetic variant in humans (MTHFR 677C>T) results in reduced enzyme activity and has been linked to various disorders, including male infertility. A new animal model has been created by reproducing the human equivalent of the polymorphism in mice using CRISPR/Cas9. Biochemical parameters in the Mthfr 677TT mice recapitulate alterations found in MTHFR 677TT men. Our aims were to characterize the sperm DNA methylome of the Mthfr 677CC and TT mice on a control diet (2 mg folic acid/kg diet) and assess the effects of folic acid supplementation (10 mg/kg diet) on the sperm DNA methylome. Body and reproductive organ weights, testicular sperm counts, and histology were examined. DNA methylation in sperm was assessed using bisulfite pyrosequencing and whole-genome bisulfite sequencing (WGBS). Reproductive parameters and locus-specific imprinted gene methylation were unaffected by genotype or diet. Using WGBS, sperm from 677TT mice had 360 differentially methylated tiles as compared to 677CC mice, predominantly hypomethylation (60% of tiles). Folic acid supplementation mostly caused hypermethylation in sperm of males of both genotypes and was found to partially correct the DNA methylation alterations in sperm associated with the TT genotype. The new mouse model will be useful in understanding the role of MTHFR deficiency in male fertility and in designing folate supplementation regimens for the clinic.

Folate Deficiency and/or the Genetic Variant Mthfr677C >T Can Drive Hepatic Fibrosis or Steatosis in Mice, in a Sex-Specific Manner.

SCOPE: Disturbances in one-carbon metabolism contribute to nonalcoholic fatty liver disease (NAFLD) which encompasses steatosis, steatohepatitis, fibrosis, and cirrhosis. The goal is to examine impact of folate deficiency and the Mthfr677C >T variant on NAFLD. METHODS AND RESULTS: This study uses the new Mthfr677C >T mouse model for the human MTHFR677C >T variant. Mthfr677CC and Mthfr677TT mice were fed control diet (CD) or folate-deficient (FD) diets for 4 months. FD and Mthfr677TT alter choline/methyl metabolites in liver and/or plasma (decreased S-adenosylmethionine (SAM):S-adenosylhomocysteine (SAH) ratio, methyltetrahydrofolate, and betaine; increased homocysteine [Hcy]). FD, with contribution from Mthfr677TT, provokes fibrosis in males. Studies of normal livers reveal alterations in plasma markers and gene expression that suggest an underlying predisposition to fibrosis induced by FD and/or Mthfr677TT in males. These changes are absent or reverse in females, consistent with the sex disparity of fibrosis. Sex-based differences in methylation potential, betaine, sphingomyelin, and trimethylamine-N-oxide (TMAO) levels may prevent fibrogenesis in females. In contrast, Mthfr677TT alters choline metabolism, dysregulates expression of lipid metabolism genes, and promotes steatosis in females. CONCLUSION: This study suggests that folate deficiency predisposes males to fibrosis, which is exacerbated by Mthfr677TT, whereas Mthfr677TT predisposes females to steatosis, and reveal novel contributory mechanisms for these NAFLD-related disorders.

Meta-analysis of MTHFR C677T polymorphism and type 2 diabetes mellitus in MENA region.

BACKGROUND AND AIMS: The association of the C677T polymorphism of the Methylenetetrahydrofolate Reductase (MTHFR) gene with susceptibility to type 2 diabetes mellitus (T2DM) has been widely debated. Therefore, our aim is to conclusively resolve this controversy in the Middle East and North Africa region population through a meta-analysis. MATERIEL AND METHODS: We identified relevant articles by searching literature databases, such as PubMed, Web of Science, and Science Direct, to retrieve studies that examined the association between the MTHFR C677T polymorphism and the risk of developing T2DM. Using meta-analysis, we calculated the odds ratio (OR) and confidence interval (CI) values of these studies to assess the susceptibility to T2DM related to the C677T polymorphism of MTHFR gene. RESULTS: In this meta-analysis, we included a total of 13 publications comprising 2072 T2DM patients and 2164 control subjects. The results of the meta-analysis suggested that there is a significant association between the C677T polymorphism and T2DM risk in overall comparisons for allele contrasts (T vs C): OR = 1.25, 95% CI = 1.04-1.50, p = 0.015 and homozygous (TT vs CC): OR = 1.44, 95% CI = 1.01-2.05, p = 0.038). Subgroup analysis revealed that the C677T polymorphism is associated with a risk of T2DM in Asian populations, while there is no significant association between this polymorphism and T2DM in Caucasian and African populations. Furthermore, there was no evidence of publication bias. CONCLUSION: Our study's results suggest that the allele contrast of the C677T polymorphism of the MTHFR gene is associated with an increased risk of T2DM in the overall population, particularly among Asians.

Association of methylenetetrahydrofolate reductase gene variant C677T and folate levels in non-syndromic cleft lip/palate among Sindhi, Pakistani population.

The object ives of this study were to determine the association of methylenetetrahydrofolate reduc tase (MTHFR) gene variant C67 7 T with non -syndromic cl eft lip/palate (NSCLP) in Pakistani population and compare the m aternal serum foli c acid levels in NSCLP-affected and healthy group. A c om parative cross sec ti onal study was conducted between 2017 and 2019 at Liaquat U niversity of Medi cal and Health Science s, Jamshoro. Sixty motherinfant dy ads were recruited (n=120), inc luding NSCLP-affected and healthy infants alo ng with t heir mother s. The MTHFR C677T vari ant exhibited si gnificant association with NSCLP in dominant and over-domi nant models. No differences in maternal serum folic acid levels were obse rved between both th e groups; however, the folic acid intake during pre-conception period was associated w ith decreased risk for NSC LP. Our stu dy suggested that MTHFR 677 CT genotype was related with decreased risk for NSCLP in Sindhi, Pakistani, population. Pre -conception folic acid may decrease the ri sk for ora l clefts.

Correlation between gene polymorphism and adverse reactions of high-dose methotrexate in osteosarcoma patients: a systematic review and meta-analysis.

OBJECTIVE: We aimed to provide a reference based on evidence for an individualized clinical medication of high-dose methotrexate (HD-MTX) in osteosarcoma patients by evaluating the effect of gene polymorphism on adverse reactions of HD-MTX usage. METHODS: Several databases were combed for research on the association between gene polymorphisms and adverse reactions to HD-MTX up to January 2023. A meta-analysis and/or descriptive analysis on the incidence of HD-MTX-related adverse reactions were conducted by using clinical studies meeting inclusion criteria. RESULTS: Twelve studies involving 889 patients were included. There were 8, 6, 5, and 4 studies related to MTHFR C677T, MTHFR A1298C, RFC1 G80A, and MDR1 C3435T polymorphisms, respectively. The results of the meta-analysis showed that the MTHFR C677T polymorphism was associated with G3-4 hepatotoxicity, G3-4 nephrotoxicity, G3-4 gastrointestinal toxicity, and G3-4 mucositis under the recessive genetic model (MM vs. Mm/mm). Limited research showed that MTHFR C677T was associated with G3-4 nephrotoxicity in the allelic genetic model (M vs. m). MTHFR A1298C polymorphism was associated with a decreased risk of adverse reactions to HD-MTX usage, without statistical significance. This review's descriptive analysis showed no significant correlation between the RFC1 G80A, and MDR1 C3435T polymorphism and adverse reactions of HD-MTX. CONCLUSION: The MTHFR C677T mutation may enhance the risk of HD-MTX adverse reactions in osteosarcoma patients. Existing studies have not found a significant correlation between the MTHFR A1298C, RFC1 G80A, and MDR1 C3435T polymorphism and adverse reactions caused by HD-MTX. Lastly, this conclusion was limited because of few studies.

Association study between genetic polymorphisms in MTHFR and stroke susceptibility in Egyptian population: a case-control study.

Stroke is a major global disability cause, and genetic variables for multifactorial illnesses like stroke are crucial for precision medicine. The purpose of this study is to see if genetic variants in the MTHFR gene are associated with a higher risk of ischemic stroke among the Egyptian population. A case-control study was conducted at Mansoura University Hospital, involving 100 stroke patients and 150 healthy volunteers as the control group. Peripheral blood genomic DNA was isolated and single-nucleotide polymorphisms were genotyped using ARMS-PCR. The CT and TT genotypes of the C677T gene polymorphism exhibited substantial risks for having stroke disease [(OR 3.856; P ≤ 0.001); (OR 4.026; P ≤ 0.001), respectively]. The T allele was significantly more prevalent among patients compared to controls. (OR 2.517; (P = 0.001)). The over-dominant and dominant models demonstrated a substantial relationship between stroke groups at risk of developing stroke but not the Recessive model. An extensive connection was found between the MTHFR A1298C and stroke danger in three different inheritance models: dominant (CC + CA vs. AA), over-dominant (AA + CC vs AC), and allelic (C allele) (P < 0.001). A highly significant difference in blood pressure, total cholesterol, and triglycerides levels was found between patients and control. While there was no meaningful link discovered between genetic polymorphism with SBP, DBP, TG, LDL, VLDL among stroke group (P > 0.05 for each) except the CC genotype that was significantly associated with lower levels of TC and HDL when compared to CT + TT genotypes. The study evaluates a strong link among MTHFR mutations in genes and the probability to get stroke. The research significantly supports the use of MTHFR ((rs1801133) and (rs1801131) variations in stroke prediction.

ATR1 A1166C (rs5186), FII G20210A (rs1799963), FV G1691A (rs6025), FXIII 97G > T (rs11466016) and MTHFR A1298C (rs1801131) polymorphisms and the risk of ST-elevation myocardial infarction in young Mexican individuals.

BACKGROUND: Previous studies had identified genetic variants associated with Myocardial Infarction, but results are inconclusive. We examined the association between FII G20210A (rs1799963), FV G1691A (rs6025), FXIII 97G > T (rs11466016), ATR1 A1166C (rs5186) and MTHFR A1298C (rs1801131) polymorphisms and ST elevation Myocardial Infarction in young Mexican individuals. METHODS: We included a total of 350 patients with Myocardial Infarction <45 years old and 350 controls matched by age and gender. The polymorphisms were analyzed by PCR-RFLP using specific restriction enzymes. DNA fragments were separated by electrophoresis in 2% gel of agarose and visualized using SYBR green. RESULTS: The A1166C (p = 0.004) but not FXIII 97G > T (p = 0.19), G20210A (p = 0.32), G1691A (p = No significant) and A1298C (p = 0.21) polymorphisms were associated with increased risk for ST elevation Myocardial Infarction. Moreover, dyslipidemia, hypertension, smoking and family history of atherothrombotic disease were associated. CONCLUSIONS: We found that A1166C represented increased risk for ST elevation Myocardial Infarction. However, G20210A, G1691A, 97G > T, and A1298C were not associated. In addition, we had determined that Glu298Asp, PLA1/A2, TAFI Thr325Ile, ACE I/D, AGT M235T and PAI-1 4G/5G polymorphisms represented increased risk in the same group of patients. However, MTHFR C677T, AGT T174M, FV G1691A, TSP-1 N700S, MTHFR C677T and TAFI 174 M polymorphisms were no associated. Our results suggest that in young patients with ST Myocardial Infarction, those polymorphisms could contribute to premature endothelial dysfunction, atherothrombosis, vasoconstriction, increased platelet aggregation, muscle cell migration and proliferation. Further studies are required to try to better assess gene-gene and gene-modifiable factors interaction.

Relationship between methylenetetrahydrofolate reductase C677T gene polymorphism and neutrophil gelatinase-associated lipocalin in early renal injury in H-type hypertension.

OBJECTIVE: To analyse the relationship between the polymorphisms of the H-type hypertensive methylenetetrahydrofolate reductase (MTHFR) C677T gene and neutrophil gelatinase-associated lipocalin (NGAL) in early kidney injury. METHOD: A total of 279 hospitalised patients with hypertension were selected and grouped according to their homocysteine (Hcy) level. If their blood Hcy level was ≥ 10 µmol/L they were assigned to the H-type hypertensive group, and if it was < 10 µmol/L they were assigned to the non-H-type hypertensive group. Blood lipid indexes, renal function indexes and blood glucose indexes were collected, and the differences between the two groups were compared. Furthermore, MTHFR C677T genotype distribution and allele frequency and Hcy level of MTHFR C677T genotype were compared, and logistic multiple regression analysis was conducted for the correlation of different genotypes of MTHFR C677T and the early kidney injury marker NGAL. RESULTS: In the non-H-type hypertensive group, the levels of Hcy and NGAL, cystatin, blood urea nitrogen, serum creatinine, uric acid, serum ß2-microglobulin and urinary microalbumin-to-creatinine ratio increased significantly, and the glomerular filtration rate level decreased significantly, when compared with the H-type hypertensive group, with statistical differences (p < 0.05). The H-type hypertensive group and the non-H-type hypertensive group had significant differences in the CC, CT and TT genotypes and allele frequencies at the MTHFR C677T locus. The MTHFR C677T gene mutation rate of the H-type hypertensive group was significantly higher than that of the non-H-type hypertensive group. The H-type hypertensive group had higher levels of the TT genotype and CT genotype Hcy. There was a statistical difference (p < 0.05). CONCLUSION: Methylenetetrahydrofolate reductase C677T polymorphism is correlated with the Hcy level, and its gene polymorphism will affect the Hcy level. Methylenetetrahydrofolate reductase C677T polymorphism has an interactive effect with NGAL. Screening NGAL and reducing Hcy levels are valuable methods for the prevention and treatment of early renal injury in patients with H-type hypertension and help improve the prognosis of patients and their quality of life.

Association between MTHFR C677T Gene Polymorphisms and the Efficacy of Vitamin Therapy in lowering Homocysteine Levels among Stroke Patients with Hyperhomocysteinemia.

BACKGROUND: The impact of the methylenetetrahydrofolate reductase (MTHFR) C677T mutation on the relationship between plasma homocysteine (Hcy) levels and stroke has been extensively studied and documented in previous study. However, it remains unclear whether the MTHFR C677T mutation can affect the response to Hcy lowering treatment in stroke patients with hyperhomocysteinemia (HHcy). Understanding the impact of genetic factors on treatment response can help optimize personalized treatment strategies for stroke patients with HHcy. We aimed to investigate the potential association between the MTHFR C677T gene polymorphisms and the effectiveness of Hcy lowering treatment using vitamin therapy in stroke patients with HHcy. METHODS: The MTHFR C677T genotype polymorphisms were identified using polymerase chain reaction-restriction fragment length polymorphism, and the distribution of three genotypes in the MTHFR C677T gene locus was compared. The treatment effects of Hcy lowering agents were compared among patients with different genotypes. RESULTS: Among the 320 stroke patients enrolled in the study, 258 (80.6%) were diagnosed with HHcy. Of these, 162 patients (Effective Group) responded well to the clinical Hcy lowering treatment, while 96 patients (Invalid Group) failed to achieve sufficient response even after taking combination supplements of folic acid, Vitamin B6, and methylcobalamin for one month. Significant differences were observed in terms of age (p < 0.001), hypertension (p = 0.034), dyslipidemia (p = 0.022), hyperuricemia (p = 0.013) and genotype distribution of MTHFR C677T gene polymorphism (p < 0.001) between the Invalid group and the Effective group. The multivariate regression analysis revealed that the T allele (odd rations [OR], 1.327; 95% confidence interval [CI], 1.114-1.580; p = 0.0015) was independently associated with an insufficient Hcy lowering treatment effect. Additionally, the TT genotype was independently associated with insufficient response in both the codominant model (OR, 1.645; 95% CI, 1.093-2.476; p = 0.017) and the recessive model (TT versus CC + CT; OR, 1.529; 95% CI, 1.145-2.042; p = 0.004). However, no relationship was observed between CT + TT genotypes and poor treatment effect in the dominate model. CONCLUSIONS: Our findings suggested that the TT genotype and T allele of MTHFR C677T polymorphism were independently associated with an insufficient Hcy lowering treatment effect in stroke patients with HHcy.

Leiomyoma and the importance of genetic variation on genes related to the vasculature system - CßS, MTHFR, NOS3, CYBA, and ACE1.

OBJECTIVE: The link between the systemic vasculature system and tumor biology is here investigated by studying the contribution of CßS (844ins68), MTHFR (677C > T), NOS3 (4a/4b), CYBA (C242T), and ACE1 (I/D) genes to leiomyoma onset, uterus and leiomyoma volumes. METHODS: DNA samples from 130 women with leiomyomas and 527 from healthy women were genotyped by PCR or PCR-RFLP. Qui-square (χ2) or Fisher's exact test were used to test associations. All the mentioned tests were performed in IBM® SPSS® Statistics Version 28. Statistical significance was defined as a p-value < 0.05. RESULTS: Results revealed that CßS (in the codominant and allelic models, p = 0.044 and, p = 0.015, OR = 1.791 [1.114-2.879], respectively), MTHFR (in the codominant, allelic and dominant models, p = 0.009, p = 0.002, OR = 0.585 [0.416-0.824] and p = 0.003, OR = 0.527 [0.346-0.802], respectively) and ACE1 (dominant model, p = 0.045, OR = 0.639 [0.411-0.992]) genes are associated with leiomyoma onset. NOS3 4a4a genotype is associated with a lower uterus volume (p = 0.004). This study also uncovers intriguing epistatic interactions among some genes that further accentuate their roles in disease modulation. Indeed, the epistatic interactions between the CC genotype (MTHFR) and (+/+) (CßS; p = 0.003), 4b4b (NOS3; p = 0.006, OR = 2.050 [1.223-3.439]) or DD (ACE1; p < 0.001, OR = 2.362 [1.438-3.880]) were shown to be associated with the disease, while 4a presence (NOS3) in epistasis with I presence (ACE1), increased the effect protection having just the I allele presence (p = 0.029, OR = 0.446 [0.214-0.930]). CONCLUSIONS: We conclude that variation in genes related to the systemic vascular system can play a role in the onset and development of leiomyoma.

Congenital septal defects in Karachi, Pakistan: an update of mutational screening by high-resolution melting (HRM) analysis of MTHFR C677T.

BACKGROUND: Congenital heart defects (CHDs) are the heart structural malformations present at birth. Septal defects account for 40% of CHD, including atrial, ventricular and atrioventricular septal defects. In Pakistan, the prevalence of CHD is 3.4 in 1000, and a study estimated that 60,000 babies are born with CHD annually. Methylenetetrahydrofolate reductase (MTHFR), a chief enzyme, involved in the folate metabolism. The missense mutation, C677T (rs1801133), exists in MTHFR gene, results in a MTHFR thermolabile variant having low enzymatic activity. The study is aim to identify the MTHFR C677T variant association with septal defects. METHODS: Samples of 194 CHD patients (age [Formula: see text]= 5.8 ± 5.1) and 50 normal echo controls (age [Formula: see text]= 6.0 ± 4.9), confirmed by pediatric consultant, were collected. Extracted DNA, quantified by agarose gel electrophoresis and nanodrop, was screened for SNP by high-resolution melting (HRM). Further, HRM results were confirmed using restriction analysis and sequencing. HRM was simply and precisely genotyped the samples within 3 h at low cost. RESULTS: Genotypic data suggested that heterozygous mutant (CT) was frequent in congenital septal defect patients (0.26) which was higher than controls (0.143), p > 0.05. Mutant (TT) genotype was not found in this study. CONCLUSIONS: rs1801133 has lack of significant association with congenital septal defects. The absence of TT genotype in this study suggesting the role of natural selection in targeted population. HRM is an easy, fast and next generation of PCR, which may be used for applied genomics.

Association of epistatic effects of MTHFR, ACE, APOB, and APOE gene polymorphisms with the risk of myocardial infarction and unstable angina in Egyptian patients.

Despite remarkable discoveries in the genetic susceptibility of coronary artery disease (CAD), a large part of heritability awaits identification. Epistasis or gene-gene interaction has a profound influence on CAD and might contribute to its missed genetic variability; however, this impact was largely unexplored. Here, we appraised the associations of gene-gene interactions and haplotypes of five polymorphisms, namely methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, angiotensin converting enzyme (ACE) insertion/deletion (I/D), apolipoprotein B (APOB) R3500Q, and apolipoprotein E (APOE) ε4 with the risk of myocardial infarction (MI) and unstable angina (UA). Gene-environment interactions with traditional risk factors and clinical data were also scrutinized. This study recruited 100 MI, 50 UA patients, and 100 apparently healthy controls. Logistic regression models were employed in association analyses. We remarked that the single locus effect of individual polymorphisms was relatively weak; however, a magnified effect of their combination via gene-gene interaction may predict MI risk after adjustment for multiple comparisons. Only MTHFR C677T, ACE I/D, and APOB R5300Q were associated with the risk of UA, and the ACE I/D-R3500Q interaction posed a decreased UA risk. APOB R3500Q was in strong linkage disequilibrium with MTHFR C677T, ACE I/D, and APE ε4 polymorphisms. The TCDGε3, CADGε4, and TADGε4-C677T-A1298C-ACE I/D-R3500Q-APOE haplotypes were associated with escalating MI risk, while the CDG or CIG-C677T-ACE I/D-R3500Q haplotype was highly protective against UA risk compared to controls. Interestingly, the CADGε4 and CAIGε3 haplotypes were strongly associated with the presence of diabetes and hypertension, respectively in MI patients; both haplotypes stratified patients according to the ECHO results. In UA, the CDG haplotype was negatively associated with the presence of diabetes or dilated heart. Conclusively, our results advocate that a stronger combined effect of polymorphisms in MTHFR, ACE, APOB, and APOE genes via gene-gene and gene-environment interactions might help in risk stratification of MI and UA patients.

Effects of gene polymorphisms on delayed MTX clearance, toxicity, and metabolomic changes after HD-MTX treatment in children with acute lymphoblastic leukemia.

This study aims to assess the role of methotrexate-related gene polymorphisms in children with acute lymphoblastic leukemia (ALL) during high-dose methotrexate (HD-MTX) therapy and to explore their effects on serum metabolites before and after HD-MTX treatment. The MTHFR 677C>T, MTHFR 1298A>C, ABCB1 3435C>T, and GSTP1 313A>G genotypes of 189 children with ALL who received chemotherapy with the CCCG-ALL-2020 regimen from January 2020 to April 2023 were analyzed, and toxic effects were reported according to the Common Terminology Criteria for Adverse Events (CTCAE, version 5.0). Fasting peripheral blood serum samples were collected from 27 children before and after HD-MTX treatment, and plasma metabolites were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS). The results of univariate and multivariate analyses showed that MTHFR 677C>T and ABCB1 3435 C>T gene polymorphisms were associated with the delayed MTX clearance (P < 0.05) and lower platelet count after treatment in children with MTHFR 677 mutation compared with wild-type ones (P < 0.05), and pure mutations in ABCB1 3435 were associated with higher serum creatinine levels (P < 0.05). No significant association was identified between MTHFR 677C>T, MTHFR 1298A>C, ABCB1 3435 C>T, and GSTP1 313A>G genes and hepatotoxicity or nephrotoxicity (P > 0.05). However, the serum metabolomic analysis indicated that the presence of the MTHFR 677C > T gene polymorphism could potentially contribute to delayed MTX clearance by influencing L-phenylalanine metabolism, leading to the occurrence of related toxic side effects. CONCLUSION: MTHFR 677C>T and ABCB1 3435 C>T predicted the risk of delayed MTX clearance during HD-MTX treatment in children with ALL. Serum L-phenylalanine levels were significantly elevated after HD-MTX treatment in children with the MTHFR 677C>T mutation gene. TRIAL REGISTRATION: This study was registered at the Chinese Clinical Trial Registry (registration number: ChiCTR2000035264; registration: 2020/08/05; https://www.chictr.org.cn/ ). WHAT IS KNOWN: • MTX-related genes play an important role in MTX pharmacokinetics and toxicity, but results from different studies are inconsistent and the mechanisms involved are not clear. WHAT IS NEW: • Characteristics, prognosis, polymorphisms of MTX-related genes, and metabolite changes were comprehensively evaluated in children treated with HD-MTX chemotherapy. • Analysis revealed that both heterozygous and pure mutations in MTHFR 677C>T resulted in a significantly increased risk of delayed MTX clearance, and that L-phenylalanine has the potential to serve as a predictive marker for the metabolic effects of the MTHFR 677C>T polymorphism.