Mutational and structural studies of (ßα)8-barrel fold methylene-tetrahydropterin reductases utilizing a common catalytic mechanism.

Methylene-tetrahydropterin reductases catalyze the reduction of a methylene to a methyl group bound to a reduced pterin as C1 carrier in various one-carbon (C1) metabolisms. F420-dependent methylene-tetrahydromethanopterin (methylene-H4MPT) reductase (Mer) and the flavin-independent methylene-tetrahydrofolate (methylene-H4F) reductase (Mfr) use a ternary complex mechanism for the direct transfer of a hydride from F420H2 and NAD(P)H to the respective methylene group, whereas FAD-dependent methylene-H4F reductase (MTHFR) uses FAD as prosthetic group and a ping-pong mechanism to catalyze the reduction of methylene-H4F. A ternary complex structure and a thereof derived catalytic mechanism of MTHFR is available, while no ternary complex structures of Mfr or Mer are reported. Here, Mer from Methanocaldococcus jannaschii (jMer) was heterologously produced and the crystal structures of the enzyme with and without F420 were determined. A ternary complex of jMer was modeled on the basis of the jMer-F420 structure and the ternary complex structure of MTHFR by superimposing the polypeptide after fixing hydride-transferring atoms of the flavins on each other, and by the subsequent transfer of the methyl-tetrahydropterin from MTHFR to jMer. Mutational analysis of four functional amino acids, which are similarly positioned in the three reductase structures, indicated despite the insignificant sequence identity, a common catalytic mechanism with a 5-iminium cation of methylene-tetrahydropterin as intermediate protonated by a shared glutamate. According to structural, mutational and phylogenetic analysis, the evolution of the three reductases most likely proceeds via a convergent development although a divergent scenario requiring drastic structural changes of the common ancestor cannot be completely ruled out.

A Refractory Livedoid Vasculopathy Accompanied by Methylene Tetrahydrofolate Reductase Gene Polymorphism Successfully Treated with Hyperbaric Oxygen Therapy.

Livedoid vasculopathy (LV) is a chronic coagulation disorder characterized by recurrent, painful ulcers on the lower extremities. Methylene tetrahydrofolate reductase (MTHFR) gene polymorphism is associated with coagulopathy. Therapeutic options usually include anti-inflammatory or immunosuppressive agents. However, the condition is still highly challenging to manage and no consensus over the first-line treatment for LV exists. Furthermore, when LV is accompanied with MTHFR gene polymorphism, clinical presentations could be more severe and resistant to treatment. We report a case of refractory LV accompanied by MTHFR gene polymorphism, which was successfully treated with hyperbaric oxygen therapy (HBOT). A 63-year-old female patient presented with multiple painful ulcers, atrophie blanches, and retiform purpura on both lower legs and feet. Histopathologic findings were compatible with LV. LV was diagnosed based on these clinicopathological findings. Following the diagnosis, we treated the patient with pentoxifylline, aspirin, systemic corticosteroid, antihistamine, and antibiotics. In spite of six-month treatment, the skin lesions did not improve; hence, HBOT was performed. It was performed at 2.0 absolute atmosphere for 120 minutes each time, three times a week. After 4 sessions, the ulcers began to heal and after 13 sessions, the skin lesions almost healed. During the eight-month follow-up period, the skin ulcers did not recur and the symptoms remained stable. Additionally, it was confirmed that she had MTHFR gene polymorphism after a genetic test. In conclusion, we wish to provide evidence regarding the effectiveness of HBOT and suggest that HBOT might be a considerable treatment option in refractory LV.

Dental complications in homocystinurias.

Background: Cystathionine beta synthase deficiency (causing classical homocystinuria) has been associated with high-arched palates and crowded teeth, but little has been said about other oral health complications. Other homocystinurias (e.g., the remethylation defects) also have had little reported in terms of oral health. Individuals with the homocystinurias have been described as having bone density issues which can correlate with oral health. Moreover, elevations in homocysteine have a theoretical impact on tooth health and the paucity of clinical reports of oral health issues in homocystinuria may be the consequence of lack of attention by the medical community. Significance: Oral health is essential to overall health. If inadequate attention is paid to the oral health complications which can be seen in homocystinurias, then appropriate referrals and attention in therapeutic guidelines will not reflect the importance of oral health. Specific aims/research question: What oral health complications are reported by individuals with homocystinurias? Do these differ according to diagnosis? Methods: Data were collected from patients with homocystinurias by a series of questionnaires using the RARE-X platform. All subjects were consented prior to the collection of their data. All research was performed in accordance with the Declaration of Helsinki. Demographic data were collected as the initial questionnaire and other data were collected via the oral health questionnaire. Analysis: Questionnaires were opened to the community in mid-2022 and collection of data for this study ended with data submitted up to November 2022. Descriptive statistics were done. Due to the small size of the cohort, additional statistical analyses were not attempted. Results: Patients with homocystinuria, not related to cystathionine beta synthase deficiency, are reporting some tooth structure differences. The cohort taken as a whole does not have increased risk for gingivitis, but there appears to be a risk for long-term gum disease possibly due to the rate of osteoporosis/osteopenia in this population. A large number of individuals have malalignment and malocclusion of the teeth. These data highlight oral health as an important component of care in individuals with the homocystinurias as is true of the general population at large.

Crystal structure of FAD-independent methylene-tetrahydrofolate reductase from Mycobacterium hassiacum.

FAD-independent methylene-tetrahydrofolate (methylene-H4 F) reductase (Mfr), recently identified in mycobacteria, catalyzes the reduction of methylene-H4 F to methyl-H4 F with NADH as hydride donor by a ternary complex mechanism. This biochemical reaction corresponds to that of the ubiquitous FAD-dependent methylene-H4 F reductase (MTHFR), although the latter uses a ping-pong mechanism with the prosthetic group as intermediate hydride carrier. Comparative genomics and genetic analyses indicated that Mfr is indispensable for the growth of Mycobacterium tuberculosis, which lacks the MTHFR encoding gene. Therefore, Mfr appears to be an excellent target for the design of antimycobacterial drugs. Here, we report the heterologous production, enzymological characterization, and the crystal structure of Mfr from the thermophilic mycobacterium Mycobacterium hassiacum (hMfr), which shows 78% sequence identity to Mfr from M. tuberculosis. Although hMfr and MTHFR have minor sequence identity and different catalytic mechanisms, their structures are highly similar, thus suggesting a divergent evolution of Mfr and MTHFR from a common ancestor. Most of the important active site residues of MTHFR are conserved and equivalently positioned in the tertiary structure of hMfr. The Glu9Gln variant of hMfr exhibits a drastic reduction of the catalytic activity, which supports the predicted function of the glutamate residue as proton donor in both hMfr and MTHFR. Thus, highly similar binding modes for the C1 -carriers and the reducing agents in hMfr and MTHFR are assumed.

Management of splanchnic vein thrombosis.

The expression splanchnic vein thrombosis encompasses Budd-Chiari syndrome and portal vein thrombosis. These disorders have common characteristics: they are both rare diseases which can cause portal hypertension and its complications. Budd-Chiari syndrome and portal vein thrombosis in the absence of underlying liver disease share many risk factors, among which myeloproliferative neoplasms represent the most common; a rapid comprehensive work-up for risk factors of thrombosis is needed in these patients. Long-term anticoagulation is indicated in most patients. Portal vein thrombosis can also develop in patients with cirrhosis and in those with porto-sinusoidal vascular liver disease. The presence and nature of underlying liver disease impacts the management of portal vein thrombosis. Indications for anticoagulation in patients with cirrhosis are growing, while transjugular intrahepatic portosystemic shunt is now a second-line option. Due to the rarity of these diseases, studies yielding high-grade evidence are scarce. However, collaborative studies have provided new insight into the management of these patients. This article focuses on the causes, diagnosis, and management of patients with Budd-Chiari syndrome, portal vein thrombosis without underlying liver disease, or cirrhosis with non-malignant portal vein thrombosis.

Juvenile patients with the homozygous MTHFR C677T genotype develop ischemic stroke 5 years earlier than wild type.

To compare age at 1st ischaemic stroke (IS) in a cohort of juvenile (< 46 years of age) IS patients evaluated for the rs1801133 polymorphism (C → T677) of the methylene tetrahydrofolate reductase (MTHFR) gene; to identify predictors of age at IS and of type of cerebral vessel involvement, small vessel disease (SVD) vs large vessel disease (LVD) responsible for the IS; to evaluate possible associations between other clinical and laboratory variables. Retrospective cohort study on 82 MTHFR TT, 54 MTHFR TC and 34 MTHFR CC participants; data regarding age, sex, age at IS, history of dyslipidaemia, hypertension, smoking, migraine and homocysteine (HC) as well as neuroimaging were collected. Age at IS was lower in MTHFR TT than MTHFR TC and CC (35 ± 4 vs 38 ± 0 vs 40 ± 3 years, respectively, p = 0.002); plasma HC (median, interquartile range) was higher in MTHFR TT than in the other groups [16.7 (11.8, 28.6) vs 11.4 (8.2, 16.1) vs 9.8 (7.9, 1.3) respectively, p < 0.0001)] and was higher in SVD than LVD [17.4 (12.4, 32.5) vs  11.4 (8.8, 16.4) p < 0.0001]. MTHFR TT independently predicted age at IS (p = 0.0008) alongside smoking both as a categorical (p = 0.003) or continuous variable (p = 0.02), whereas HC independently predicted SVD as categorical (p = 0.01) and continuous variable (p < 0.0001). Smoking positively predicted plasma HC (p = 0.005) and negatively the activated partial thromboplastin ratio (aPTTr) (p = 0.02). Juvenile IS carriers of the MTHFR TT genotype develop their 1st occlusion on average 5 years earlier compared to the CC genotype; smoking contributes to this prematurity adversely affecting plasma HC and coagulation whereas plasma HC predicts IS secondary to SVD. Public health campaigns against smoking should highlight the prematurity of IS in the juvenile population.

Is reduced ferredoxin the physiological electron donor for MetVF-type methylenetetrahydrofolate reductases in acetogenesis? A hypothesis / ¿Es la ferredoxina reducida el donante de electrones fisiológico para las metilentetrahidrofolato reductasas de tipo MetVF en la acetogénesis? Una hipótesis

The methylene-tetrahydrofolate reductase (MTHFR) is a key enzyme in acetogenic CO2 fixation. The MetVF-type enzyme has been purified from four different species and the physiological electron donor was hypothesized to be reduced ferredoxin. We have purified the MTHFR from Clostridium ljungdahlii to apparent homogeneity. It is a dimer consisting of two of MetVF heterodimers, has 14.9 ± 0.2 mol iron per mol enzyme, 16.2 ± 1.0 mol acid-labile sulfur per mol enzyme, and contains 1.87 mol FMN per mol dimeric heterodimer. NADH and NADPH were not used as electron donor, but reduced ferredoxin was. Based on the published electron carrier specificities for Clostridium formicoaceticum, Thermoanaerobacter kivui, Eubacterium callanderi, and Clostridium aceticum, we provide evidence using metabolic models that reduced ferredoxin cannot be the physiological electron donor in vivo, since growth by acetogenesis from H2 + CO2 has a negative ATP yield. We discuss the possible basis for the discrepancy between in vitro and in vivo functions and present a model how the MetVF-type MTHFR can be incorporated into the metabolism, leading to a positive ATP yield. This model is also applicable to acetogenesis from other substrates and proves to be feasible also to the Ech-containing acetogen T. kivui as well as to methanol metabolism in E. callanderi.(AU)

Is reduced ferredoxin the physiological electron donor for MetVF-type methylenetetrahydrofolate reductases in acetogenesis? A hypothesis.

The methylene-tetrahydrofolate reductase (MTHFR) is a key enzyme in acetogenic CO2 fixation. The MetVF-type enzyme has been purified from four different species and the physiological electron donor was hypothesized to be reduced ferredoxin. We have purified the MTHFR from Clostridium ljungdahlii to apparent homogeneity. It is a dimer consisting of two of MetVF heterodimers, has 14.9 ± 0.2 mol iron per mol enzyme, 16.2 ± 1.0 mol acid-labile sulfur per mol enzyme, and contains 1.87 mol FMN per mol dimeric heterodimer. NADH and NADPH were not used as electron donor, but reduced ferredoxin was. Based on the published electron carrier specificities for Clostridium formicoaceticum, Thermoanaerobacter kivui, Eubacterium callanderi, and Clostridium aceticum, we provide evidence using metabolic models that reduced ferredoxin cannot be the physiological electron donor in vivo, since growth by acetogenesis from H2 + CO2 has a negative ATP yield. We discuss the possible basis for the discrepancy between in vitro and in vivo functions and present a model how the MetVF-type MTHFR can be incorporated into the metabolism, leading to a positive ATP yield. This model is also applicable to acetogenesis from other substrates and proves to be feasible also to the Ech-containing acetogen T. kivui as well as to methanol metabolism in E. callanderi.

Study of C677T Methylene Tetrahydrofolate Reductase Gene Polymorphism as a Risk Factor for Neural Tube Defects.

INTRODUCTION: Various genetic and environmental factors contribute to the development of neural tube defects (NTDs) which are a group of neurulation defects resulting from failure of closure of embryonic neural tube. Among genetic factors is polymorphism in methylene tetrahydrofolate reductase (MTHFR) gene, giving rise to a gene variant or mutant. However, in most studies directed at finding an association between MTHFR variants and NTD, there is no clear evidence of a cause-and-effect relationship. MATERIALS AND METHODS: Forty diagnosed cases of NTDs and forty healthy individuals were investigated in a case-control study for presence of C677T MTHFR gene polymorphism. Serum folate and Vitamin B12 levels were estimated and MTHFR gene polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: It was found that 32 cases were homozygous with CC genotype and eight were heterozygous with CT genotype, whereas 35 controls had CC genotype and five had CT genotype. TT genotype was absent in both the groups. There was no statistically significant difference between both the groups. No evidence of association between MTHFR C677T polymorphism and NTDs was found. CONCLUSION: Although there was no evidence of association between MTHFR C677T polymorphism and NTDs, our study does not rule out the impact of MTHFR gene mutation on folate metabolism. The reason for absence of TT genotype and no association could be a small sample size. Larger, comprehensive, and well-designed multicentric but feasible studies involving proper subjects and appropriate and adequate controls from several hospitals may provide more meaningful data.

Folic Acid and Autism: A Systematic Review of the Current State of Knowledge.

Folic acid has been identified to be integral in rapid tissue growth and cell division during fetal development. Different studies indicate folic acid's importance in improving childhood behavioral outcomes and underline its role as a modifiable risk factor for autism spectrum disorders. The aim of this systematic review is to both elucidate the potential role of folic acid in autism spectrum disorders and to investigate the mechanisms involved. Studies have pointed out a potential beneficial effect of prenatal folic acid maternal supplementation (600 µg) on the risk of autism spectrum disorder onset, but opposite results have been reported as well. Folic acid and/or folinic acid supplementation in autism spectrum disorder diagnosed children has led to improvements, both in some neurologic and behavioral symptoms and in the concentration of one-carbon metabolites. Several authors report an increased frequency of serum auto-antibodies against folate receptor alpha (FRAA) in autism spectrum disorder children. Furthermore, methylene tetrahydrofolate reductase (MTHFR) polymorphisms showed a significant influence on ASD risk. More clinical trials, with a clear study design, with larger sample sizes and longer observation periods are necessary to be carried out to better evaluate the potential protective role of folic acid in autism spectrum disorder risk.

MTHFR C677T and A1298C variants in Mexican Mestizo infants with neural tube defects from Western Mexico.

Our study investigated the role of MTHFR C677T and A1298C variants in infants with neural tube defects (NTDs) from western Mexico. Using TaqMan allelic discrimination assay, we genotyped 101 live-born patients with NTDs (cases) and 247 controls. Our findings do not support that homozygosity or heterozygosity for the variants C677T and A1298C in the MTHFR gene are associated with NTDs in infants. However, since we have the highest worldwide frequency of homozygotes for the MTHFR C677T variant, we cannot rule out that our propensity for NTDs may be related to how such gene variant interacts with other factors, mainly with our secular patterns of inappropriate folate intake.

Epigenetic Modification in Methylene Tetrahydrofolate Reductase (MTHFR) Gene of Women with Pre-eclampsia.

BACKGROUND: Genetic and epigenetic factors play significant roles in the aetio-pathogenesis of pre-eclampsia (PE). The effects may vary across racial and geographical boundaries. The role of epigenetic modification in pre-eclampsia was studied among African populations in Lagos, Nigeria. AIM AND OBJECTIVES: This study aimed to determine the pattern of Methylene tetrahydrofolate reductase gene (MTHFR) CpG island methylation in pre-eclampsia, and evaluate associated covariates. METHODOLOGY: This study was an observational, cross-sectional, study conducted at the Lagos University Teaching Hospital and the Lagos State Island Maternity Hospital. A total of 400 pregnant women consisting of 200 pregnant women diagnosed with pre-eclampsia (study group) and 200 pregnant normotensive and apparently healthy women (control group) were recruited for the study. Demographic and clinical histories were obtained through questionnaires. The DNA Methylation status of the CpG Island in promoter region of the MTHFR gene was assessed using bisulphite conversion and methylation specific PCR method. The biochemical parameters measured in the study were: red cell folate, vitamin B12, plasma homocysteine (Hcy) and methylene tetrahydrofolate reductase enzyme level. RESULTS: Homozygous MTHFR CpG island hypomethylation pattern was significantly associated with pre-eclampsia (χ 2 = 22.96; p = 0.000), Mean values of plasma homocysteine in PE women with homozygous hypomethylation (26.1 ± 9.1 umol/L) were significantly higher than (20.1 ± 4.2 umol/L) observed in PE subjects with homozygous hypermethylation (p = 0.008). Homozygous CpG island hypomethylated pattern of the MTHFR promoter region, was associated with the lowest median MTHFR enzyme level (72.8 ± 39.8 pmol/L) compared with heterozygous methylated pattern (91.3 ± 60.9 pmol/L; p = 0.047) and homozygous methylated pattern (82.3 ± 31.0 pmol/L; 0.047). Red cell folate and Vitamin B12 levels were not significantly associated with CpG island methylation status. CONCLUSION: Epigenetic modification plays significant role in the pathogenesis of pre-eclampsia.

Associations Among Methylene Tetrahydrofolate Reductase rs1801133 C677T Gene Variant, Food Groups, and Non-alcoholic Fatty Liver Disease Risk in the Chinese Population.

OBJECTIVES: To investigate the associations among the methylene tetrahydrofolate reductase rs1801133 C677T gene variant, food groups, and the risk of non-alcoholic fatty liver disease in the Chinese population. METHODS: A study of gene polymorphism was conducted using the polymerase chain reaction method. A total of 4,049 adults participated in the study, and all underwent physical examination and genotyping. Participants filled out a dietary questionnaire to enable us to assess the frequency and quantity of food consumption. RESULTS: The important variables identified as risk factors of non-alcoholic fatty liver disease were age, smoking, sex, body mass index, hyperlipidemia, diabetes, and methylene tetrahydrofolate reductase genotype (T - allele carriers). The homocysteine content was higher in the non-alcoholic fatty liver disease group than in the control group, and was higher in the T- allele than C- allele carriers. The homocysteine content was the highest in the T- allele carriers. Additionally, certain food groups such as milk and beans were associated with a lower risk of non-alcoholic fatty liver disease. Food groups such as meat, were associated with a higher risk of non-alcoholic fatty liver disease. Fresh fruit and vegetables, salted and smoked foods, desserts, cereals, fish, and eggs were not associated with the risk of non-alcoholic fatty liver disease. However, the influence of salted and smoked foods on non-alcoholic fatty liver disease was different in the C-allele and T-allele carriers of methylene tetrahydrofolate reductase (CT + TT vs. CC, OR = 1.196, P = 0.041 for 1-4 times food per week, OR = 1.580, P = 0.004 for 5-7 times per week). Similarly, salted and smoked foods were also a risk factor for the development of non-alcoholic steatohepatitis in patients with non-alcoholic fatty liver disease. CONCLUSION: This study found that the T-allele of the C677T variant of methylene tetrahydrofolate reductase was a risk factor for non-alcoholic fatty liver disease among Chinese people. These results can likely aid the development of novel approaches for managing non-alcoholic fatty liver disease risk.

The risk stratification of coronary vascular disease as linked to homocysteine, its modulating genes, genetic polymorphisms, conventional predictors, and with antihypertensive medicaments.

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

Hyperhomocysteinemia: a trigger for complement-mediated TMA?

A 34-year-old man of North African descent was referred to the emergency department because of malignant hypertension (220/113 mmHg), acute visual disturbances and acute kidney failure (serum creatinine 14.0 mg/dL). Blood analysis was compatible with thrombotic microangiopathy (TMA). Kidney biopsy confirmed this diagnosis with histological changes including intimal edema, arteriolar thrombi, and severe tubulointerstitial damage. Fundoscopy showed hypertensive retinopathy stage IV. Subsequent biochemical screening revealed normal complement testing and a marked elevation in homocysteine concentration (161 µmol/L; normal value 7-15 µmol/L). Other secondary causes of TMA were excluded. Further genetic testing for cobalamin C (cblC) deficiency showed no pathogenic mutations in the MMACHC gene. However, a homozygous c.665C>T polymorphism (NM_005957.4) in the methylenetetrahydrofolate reductase (MTHFR) gene was found explaining the severe hyperhomocysteinemia due to reduced activity of MTHFR. Additional genetic testing for alternative complement pathway proteins showed mutations in the genes encoding factor H and factor B, both categorized as possibly pathogenic using mutation prediction software. This is the first described case of TMA in a patient with severe hyperhomocysteinemia caused by a genetic defect other than cblC. We postulate that endothelial damage due to hyperhomocysteinemia and hypertension could have triggered the TMA episode in this patient with two possible predisposing pathogenic mutations in the alternative complement pathway. Furthermore, our case demonstrates the need for complete full diagnostic testing in patients with TMA.

Thromboelastogram parameters and MTHFR gene polymorphism in the diagnosis of adverse fetal pregnancy outcomes / 中国输血杂志

【Objective】 To retrospectively analyze the situation of patients with adverse fetal outcomes by thromboelastogram (TEG) parameters and, MTHFR gene polymorphism, so as to provide molecular biological diagnosis basis for patients with adverse pregnancy outcomes, and a new scheme for early prevention and treatment of women of childbearing age with MTHFR gene polymorphism. 【Methods】 A total of 100 women with adverse fetal pregnancy outcomes were selected as the adverse pregnancy group, and 100 healthy women of childbearing age with normal pregnancy history were selected as the controls. MTHFR gene C677T and A1298C polymorphisms were detected by polymerase chain reaction (PCR). TEG and blood coagulation were detected in the experimental group. 【Results】 The A1298C gene polymorphism(AA、CC、AC; A、C) was similar in both adverse pregnancy group and the controls. The frequency distribution of C, T allele of MTHFR gene C677T was statistically significant (χ2=4.60, P<0.05, OR =1.645, 95% CI: 1.042~2.595). TT and CT+ CC types showed significant different association with the factors of stillbirth(χ2 =7.49, P<0.05). MA value of TEG in the diagnosis of TT type of C677T genotypes MTHFR in 32 patients with adverse pregnancy outcome was analyzed. The area under the AUC curve of MA value was 0.795. 【Conclusion】 MTHFR C677T polymorphism TT with TEG parameter hypercoagulability is an important risk factor in the occurrence of pregnancy stillbirth in adverse pregnancy outcomes.

Methylene tetrahydrofolate reductase (MTHFR) and vascular endothelial growth factor (VEGF) polymorphisms in Brazilian patients with Hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC)

OBJECTIVE: The folate pathway is involved in hepatic carcinogenesis and angiogenesis. Polymorphisms in genes related to such processes, including methylene tetrahydrofolate reductase (MTHFR) and vascular endothelial growth factor (VEGF)] may play an important role in the development of hepatocellular carcinoma (HCC). The objective of this study was to evaluate MTHFR and VEGF polymorphisms in Brazilian patients with hepatitis C virus (HCV)-related HCC. METHODS: A total of 119 patients diagnosed with confirmed HCC and HCV were included in the study. SNP genotyping assays were performed using real-time PCR. VEGFA (rs2010963, rs3025039, and rs833061) and MTHFRC677T (rs1801133, rs1801131) polymorphisms were evaluated. RESULTS: The C alleles of MTHFR (rs1801131) and VEGF (rs2010963) were associated with protection against the development of multinodular HCC, while the T allele of MTHFR (rs1801133) was associated with a higher risk of multinodular presentation [p=0.04 OR 1.835 CI (1.022-3.297)]. Multivariate analysis revealed that the GG/GC genotypes of VEGF rs2010963 were independently associated with multinodular tumors at diagnosis (p=0.013; OR 4.78 CI (1.38-16.67)]. CONCLUSION: Our results suggest that these polymorphisms may increase the risk of rapid tumor progression in patients with HCV infection. This subgroup of patients with HCC and who present polymorphism is more likely to be diagnosed with multinodular disease and not be amenable to receiving curative treatments. These data must be validated in larger cohorts, and the screening intervals can be customized based on genetic history.

Relationship between granulomatous lobular mastitis and methylene tetrahydrofolate reductase gene polymorphism.

BACKGROUND: Variations in the methylene tetrahydrofolate reductase (MTHFR) gene have been reported as risk factors for numerous conditions, including cardiovascular disease, thrombophilia, stroke, hypertension and pregnancy-related complications. Moreover, it was reported there is an association between breast cancer and mutations in MTHFR-C677T. However, whether there is an association between MTHFR gene polymorphism and granulomatous lobular mastitis or not has been rarely investigated. AIM: To analyze the association between MTHFR gene polymorphism and granulomatous lobular mastitis. METHODS: Fifty-one patients with granulomatous lobular mastitis admitted to The First Hospital of Kunming were selected as study samples. Their hospitalization time ranged from February 2018 to February 2019. The 51 patients were included in the experimental group, and another 51 women who underwent physical examination at The First Hospital of Kunming in the same period were included in the control group. Deoxyribonucleic acid and MTFR genetic polymorphism testing were performed in each group. The association between MTHFR gene polymorphism and granulomatous lobular mastitis was observed. RESULTS: There were significant differences in genotype frequency and allele frequency of C/C and C/T between the experimental group and the control group (all P < 0.05). However, there was no significant difference in frequency of T/T genotype between the two groups (P > 0.05). In addition, there was no significant difference in genotype frequency and allele frequency of A/A, A/C and C/C between the two groups (P > 0.05). CONCLUSION: MTHFR gene C677T locus polymorphism is closely related to granulomatous lobular mastitis.

Genetic risk factors for venous thromboembolism among infertile men with Klinefelter syndrome.

BACKGROUND: Klinefelter syndrome (KS) is one of the commonest sex chromosome disorders. Affected males become infertile and highly susceptible to several health problems, including vascular thromboembolism (VTE). The risk of VTE may be exacerbated by an underlying genetically inherited thrombophilia. In this study, we aimed to investigate the genotype and allele frequencies of common gene polymorphisms related to hereditary thrombophilia in infertile males with KS compared to normal, fertile men. METHODS: Eighty-five infertile males with KS and 75 healthy control males were included in this case-control study. Genetic testing was done using an extended thrombophilia gene panel by Multiplex PCR reverse hybridization method. RESULTS: There was an increased frequency of mutant alleles and heterozygous genotypes of FV Leiden, FV H 1299R, Pro G20210A, MTHFR C677T and PAI-1 4G/5G thrombophilic gene polymorphisms in KS patients compared to the control group. It was shown that 10.7% of KS patients had the A3 haplotype of the EPCR gene in comparison to 5.3% of control patients. The A3/A3 genotype was found only in KS patients (7.1%). Carriers of more than one mutant allele in KS patients exceeded the control (p < 0.001). CONCLUSION: A high prevalence of thrombophilic gene polymorphisms and the coexistence of different mutant alleles were evident in infertile KS males. These data highlight the importance of conducting further studies to understand the role of hereditary thrombophilia in predicting venous thrombosis in patients with Klinefelter syndrome.

MEK Inhibitor-Associated Central Retinal Vein Occlusion Associated with Hyperhomocysteinemia and MTHFR Variants.

BACKGROUND: Central retinal vein occlusion (CRVO) is a visually threatening event that has rarely been observed in patients taking MEK1/2 inhibitors and that may necessitate permanent discontinuation of a potentially efficacious therapy. We investigated the clinical characteristics of CRVO in patients on mitogen-activated protein kinase kinase (MEK) inhibition to better understand their predisposing factors and clinical course. CASE SERIES: This was a single-center, retrospective cohort study (between December 2006 and September 2018). Three of 546 patients enrolled in 46 prospective trials involving treatment with MEK inhibitors at Memorial Sloan Kettering Cancer Center were identified as having CRVO. Clinical examination and course, multimodal ophthalmic imaging, and serum laboratory results (including homocysteine levels and genetic variants of methylene tetrahydrofolate reductase [MTHFR]) were reviewed for the 3 affected patients. All 3 patients with MEK inhibitor-associated CRVO had elevated serum homocysteine and gene variants of MTHFR (1 homozygous for A1298C, 1 heterozygous for A1298C, and 1 homozygous for C677T). Following intravitreous injections of anti-VEGF and discontinuation of drug, all patients regained vision to their baseline. DISCUSSION: MEK inhibitor-associated CRVO is a rare event which can exhibit visual recovery after drug cessation and intravitreous anti-VEGF injections. In this cohort, it was associated with hyperhomocysteinemia and genetic mutations in MTHFR, suggesting a potential role for hyperhomocysteinemia screening prior to initiation of MEK inhibitor therapy.