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.

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.

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.

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.

Contribution of genetic polymorphism of methylene tetrahydrofolate reductase on the effect of methotrexate in ectopic pregnancy patients.

BACKGROUND: Methotrexate (MTX) is the prior drug in ectopic pregnancy (EP). However, approximately 10% of patients suffer from failure by MTX therapy. Reduced folate carrier 1 (RFC1), methylene tetrahydrofolate reductase (MTHFR), and dihydrofolate reductase (DHFR) are involved in the transport and effects of MTX in vivo. In the present study, we aim to investigate the relationship between the genetic polymorphisms of RFC1, MTHFR, and DHFR and the clinical efficacy of MTX in tubal pregnancies. METHODS: 100 patients of EP were enrolled in this study. Polymorphisms of RFC1 G80A, MTHFR C677T, and DHFR A-317G were genotyped. ß-hCG level was detected in day 0, 4, and 7 after MTX injection. Association of MTX efficacy and genetic polymorphisms was analyzed. RESULTS: Methylene tetrahydrofolate reductase C677T was associated with MTX treatment (P = .017). The success rate of first MTX injection was superior in patients with harboring mutation allele of MTHFR gene than that in patients with wild-type gene (P = .001). However, there was no significant association between the polymorphisms of RFC1 G80A, DHFR A-317G, and surgical treatment (P = .709 and .476, respectively). In addition, ß-hCG level decrement was not significantly changed by MTX injection with different polymorphisms of RFC1, MTHFR, and DHFR on either day 4 (P = .214, 0.197 and 0.270, respectively) or day 7 (P = .172, .554, and .726, respectively). CONCLUSION: Our results suggested that the reliable indicator was polymorphism of MTHFR C677T in failure by MTX injection.

Prevalence of factor V leiden, MTHFR C677T and MTHFR A1298C polymorphisms in patients with deep vein thrombosis in Central Iran.

Deep vein thrombosis (DVT) is a common disease, especially among elderly patients, which is associated with high costs of treatment and high rates of recurrence. The risk factors for venous thrombosis are primarily related to hypercoagulability, which can be genetic or acquired, or because of immobilization and venous stasis. Among relevant genetic markers are a number of common polymorphisms and mutations in the genes coding for Factor V leiden and methylenetetrahydrofolate reductase. Differential associations of these polymorphisms have been reported in different populations with DVT due to ethnic variations. However, no study has been reported with respect to these polymorphisms in DVT in Iran. Thus, the aim of the present study is to determine the prevalence of FVL, MTHFR C677T and MTHFR A1298C gene polymorphisms in patients with DVT in central Iran. In the present cross-sectional study, a total of 100 patients with first and recurrent episodes of DVT and age less than 70 years were recruited during 2016-2017. Blood sample was collected from the recruited patients and FVL mutation was screened using ARMS-PCR method, MTHFR C677T and MTHFR A1298C mutations were screened using PCR-RFLP method. The results revealed that MTHFR A1298C gene polymorphism in both homozygote and heterozygote form was found to be most frequent i.e. 77% among cases, followed by MTHFR C677T (67%) and FVL (17%). The study highlights the importance of screening of these genetic markers among patients with DVT in this region.

Methylene Tetrahydrofolate Reductase (MTHFR) rs868014 Polymorphism Regulated by miR-1203 Associates with Risk and Short Term Outcome of Ischemic Stroke.

BACKGROUND/AIMS: Genetic polymorphisms of methylene tetrahydrofolate reductase (MTHFR) were associated with ischemic stroke risk. This study analyzed MTHFR polymorphisms at the 3'-untranslated region for association with risk and outcome of ischemic stroke in a Chinese Han population. METHODS: 500 patients and 600 healthy volunteers were enrolled for MTHFR rs868014 genotyping identified bioinformatically. The binding of miR-1203 to MTHFR rs868014 was determined by luciferase assay, MTHFR expression was assessed using qRT-PCR, and plasma homocysteine levels were assayed by ELISA. RESULTS: Cigarette smoking, alcohol consumption, diabetes, hypertension (all P <0.001), low levels of serum high-density lipoprotein-C (P = 0.01), and high levels of serum low-density lipoprotein-C (P = 0.005) were associated with an increased risk of developing ischemic stroke. BMI and total serum cholesterol concentration was not associated with ischemic stroke. MTHFR rs868014 TC and CC genotypes were significantly associated with increased risk of ischemic stroke compared with the TT genotype (OR: 1.52; 95% CI: 1.01-3.39 for TC genotype, while OR: 1.99; 95% CI: 1.29-3.88 for CC genotype). Furthermore, the MTHFR rs868014 SNP was associated with a poor short-term ischemic stroke outcome. qRT-PCR confirmed that MTHFR rs868014 TC or CC genotypes could facilitate miR-1203 binding leading to low MTHFR levels in cells. In addition, patients carrying the MTHFR rs868014 TC or CC genotypes were associated with accumulation of serum tHcy and a poor ischemic stroke outcome. Linkage disequilibrium analysis indicated that the newly identified SNP rs868014 was strongly linked with the MTHFR A1298C polymorphism. CONCLUSION: This study demonstrates that the MTHFR rs868014 SNP is associated with increased risk in developing ischemic stroke, miR-1203 binding, low MTHFR levels in cells, and poor shot term outcome of patients.

Biochemical and genetic predictors and correlates of response to lamotrigine and folic acid in bipolar depression: Analysis of the CEQUEL clinical trial.

OBJECTIVES: CEQUEL (Comparative Evaluation of QUEtiapine plus Lamotrigine combination versus quetiapine monotherapy [and folic acid versus placebo] in bipolar depression) was a double-blind, randomized, placebo-controlled, parallel group, 2×2 factorial trial that examined the effect of adding lamotrigine and/or folic acid (FA) to quetiapine in bipolar depression. Lamotrigine improved depression, but its effectiveness was reduced by FA. We investigated the baseline predictors and correlates of clinical response, and the possible basis of the interaction. METHODS: The main outcome was change in depressive symptoms at 12 weeks, measured using the Quick Inventory for Depressive Symptoms-self report version 16 (QIDS-SR16). We examined the relationship between symptoms and lamotrigine levels, and biochemical measures of one-carbon metabolism and functional polymorphisms in catechol-O-methyltransferase (COMT), methylene tetrahydrofolate reductase (MTHFR) and folate hydrolase 1 (FOLH1). RESULTS: Lamotrigine levels were unaffected by FA and did not differ between those participants who achieved remission and those with persisting symptoms. When participants with subtherapeutic serum levels were excluded, there was a main effect of lamotrigine on the main outcome, although this remained limited to those randomized to FA placebo. None of the biochemical measures correlated with clinical outcome. The negative impact of FA on lamotrigine response was limited to COMT Met carriers. FOLH1 and MTHFR had no effect. CONCLUSIONS: Our results clarify that FA's inhibition of lamotrigine's efficacy is not a pharmacokinetic effect, and that low serum lamotrigine levels contributed to lamotrigine's lack of a main effect at 12 weeks. We were unable to explain the lamotrigine-FA interaction, but our finding that it is modulated by the COMT genotype provides a starting point for follow-on neurobiological investigations. More broadly, our results highlight the value of including biochemical and genetic indices in randomized clinical trials.

MTHFR A1298C and C677T Polymorphisms Are Associated with Increased Risk of Venous Thromboembolism: A Retrospective Chart Review Study.

BACKGROUND: Methylene tetrahydrofolate reductase (MTHFR) is a key enzyme in homocysteine metabolism. This study aims to determine the impact of MTHFR polymorphisms on plasma homocysteine levels and risks of venous thromboembolism (VTE). METHODS: This retrospective chart review study included a total of 188 subjects who were tested for MTHFR polymorphisms at Metrowest Coagulation Laboratory between April 2011 and April 2016. Two independent coders were trained to extract relevant clinical data for statistical analysis. RESULTS: VTE occurred in 50% of patients with compound mutation, compared with only 28.6% of subjects from the wild-type group. Patients with heterozygous or homozygous A1298C or C677T variants had an intermediate risk of VTE. The median homocysteine level in the wild-type group was slightly lower than that of heterozygous or homozygous MTHFR variants. The difference, however, was not significant (p = 0.6193). Moreover, there was no difference in plasma homocysteine level between patients with VTE versus VTE-free (p = 0.4923). CONCLUSIONS: Heterozygous or homozygous MTHFR variants, especially a compound mutation, are associated with increased risk of VTE. Hyperhomocysteinemia does not correlate with MTHFR polymorphisms or VTE risk. Hence, MTHFR genotyping provides more consistent assessment of VTE risk. This information can be incorporated into risk stratification for early intervention and prophylaxis of VTE.

Association of Plasminogen Activator Inhibitor-1 Gene Polymorphisms and Methylene Tetrahydrofolate Reductase Polymorphisms with Spontaneous Miscarriages.

AIM: The objective of this study was to investigate a possible correlation between the plasminogen activator inhibitor-1 (PAI-1) and methylene tetrahydrofolate reductase (MTHFR) polymorphisms and unexplained spontaneous miscarriages (SM). MATERIALS AND METHODS: PAI-1 polymorphisms were evaluated in 150 women with pregnancy in their history. One hundred women with a history of SM formed the study group and 50 women with normal pregnancies served as the control group. Also, the combination of PAI-1 and MTHFR polymorphisms were evaluated in 138 women out of a total of 150, which included 92 women with SM in their history compared to 46 women in the control group. For statistical analysis, χ2 test, Phi, and Cramer V tests were used; p < 0.05 was taken as a statistically significant result. RESULTS: Our findings show: (a) the correlation between SM and PAI-1 mutations reaches statistical significance (p = 0.026); (b) there was a statistically significant difference between heterozygous PAI-1 in women with only 1 SM compared to the control group (p = 0.047); (c) the comparison of combinations of both mutations, PAI-1 and MTHFR, with the control group demonstrates statistical significance in favor of women with SM and both mutations (p = 0.022). CONCLUSION: PAI-1 and MTHFR polymorphisms may play an important role in pregnancy complications because heterozygous PAI-1 mutations and a combination of both PAI-1 and MTHFR mutations might contribute to SM.

A case of recurrent pancytopenia in a patient with acute promyelocytic leukemia on maintenance chemotherapy and concomitant methyltetrahydrofolate reductase and thiopurine S-methyltransferase mutation - review of literature.

Pharmacogenetics is a study of how genetic variation of an individual affects the drug response. We report a case of recurrent pancytopenia resulting from maintenance chemotherapy in a patient with acute promyelocytic leukemia and two pharmacogenetic mutations, namely, methylene tetrahydrofolate reductase C677T homozygous mutation and thiopurine methyltransferase mutation.

Frequency and association of 1691 (G>A) FVL, 20210 (G>A) PT and 677 (C>T) MTHFR with deep vein thrombosis in the population of Bosnia and Herzegovina.

The 1691 (G>A) factor V Leiden (FVL) and 20210 (G>A) prothrombin (PT) mutations are the two most common genetic risk factors in venous thromboembolism. The 677 (C>T) methylene tetrahydrofolate reductase (MTHFR) mutation is the most frequently mentioned as an independent genetic risk factor for venous thromboembolism. As there are limited published data on the prevalence of the 1691, 20210 and 677 mutations in our population, the aim of this study was to determine the frequencies and association of these deep vein thrombosis mutations in the Bosnian population. This study included 111 thromboembolic patients and 207 healthy subjects with absence of known risk factors for venous thromboembolism. Genotyping of the 1691, 20210 and 677 mutations was done by polymerase chain reaction (PCR), followed by restriction digestion with MnlI, HindIII and HinfI enzymes. Out of the 111 patients, 18.0% were heterozygous and 2.70% were homozygous for the 1691 mutation. Among 207 healthy controls, 3.86%, were heterozygous for the 1691 mutation. This study confirmed the association of the 1691 mutation with deep vein thrombosis in the Bosnian population odds ratio (OR) [95% confidence interval (CI)] = 6.0 (2.62-14.14); p = 0.0001). The 20210 mutation was detected in 2.70% of patients and it was totally absent in the control group. Allele and genotype frequency of 677 did not differ significantly between the cases and controls (χ2 = 1.03; p = 0.309).

Maternal folate status as a risk factor for autism spectrum disorders: a review of existing evidence.

Emerging evidence from epidemiological studies supports the notion that maternal folate status regulated by dietary and genetic factors early in pregnancy may influence the risk of autism spectrum disorders (ASD). In this review, we provide an overview of what is known about the role of folate in the aetiology of neurodevelopmental disorders; summarise relevant biological, genetic and epigenetic mechanisms; and synthesise the evidence from human observational studies and randomised controlled trials that have examined the relationship between maternal folate and ASD or related traits. Much of the existing literature on this topic is subject to limitations such as potential confounding by healthy behaviours and other dietary factors, and exposure assessed within limited exposure windows. As the existing evidence is inconclusive, further research remains to be conducted in order to verify this hypothesis. Complete assessment of maternal functional folate status through the pre- and peri-conceptional periods requires biological measurement of folate, vitamin B12 and homocysteine and genetic variants involved in one-carbon metabolism and epigenetic mechanisms. In addition to more complete assessment of maternal functional folate status, careful consideration of potential confounding is warranted.

Joint effects between urinary selenium and polymorphisms in methylation related genes on breast cancer risk.

The aim of this study was to explore the associations of urinary selenium and polymorphisms in methylation related genes with breast cancer risk and the interactions on the risk. The present study involved in 240 female patients with incident breast cancer and 246 age-matched controls in two affiliated hospitals of Sun Yat-sen University in Guangzhou, China, from October 2009 to July 2010. DNMT1 rs2228611, MTHFR rs1801133, and MTR rs1805087 were genotyped using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry platform. Urinary concentration of selenium was measured by inductively coupled plasma mass spectrometry. Women with urinary selenium in the second tertile had a significant reduced breast cancer risk compared to those with urinary selenium in the lowest tertile [OR (95%CI): 0.50 (0.30, 0.81)]. DNMT1 rs2228611, MTHFR rs1801133, and MTR rs1805087 were not associated with breast cancer risk. Women with the third tertile of urinary selenium had a significant reduced breast cancer risk compared to those with the lowest tertile among women only with CC genotype [OR (95%CI): 0.55 (0.30, 1.00)] but not CT/TT genotypes [OR (95%CI): 1.58 (0.73, 3.42)] of MTHFR rs1801133 (P for interaction=0.044). Our results suggested that selenium was associated with a decreased risk of breast cancer and this beneficial effect was limited to women with CC genotype of MTHFR rs1801133.

Hyperhomocysteinaemia, low folate concentrations and MTHFR C677T mutation in abdominal aortic aneurysm.

BACKGROUND: Homocysteine (Hcy) has been implicated in abdominal aortic aneurysm (AAA). However, the association of Hcy, vitamin B12, and folate in patients with AAA has not been studied in China. This study was conducted with the aim to evaluate the relationship of vitamin B12, folic acid, and Hcy levels in AAA. PATIENTS AND METHODS: 463 patients who had AAA were included in this study. 463 control subjects were age- and sex-matched with the patients. In all of the subjects, we evaluated total plasma levels Hcy, vitamin B12, folic acid and the distribution of the C677T methylenetetrahydrofolate reductase (MTHFR) gene mutation. RESULTS: The mean plasma Hcy levels were significantly higher in patients with AAA compared with controls (18.37 ± 6.97 vs. 12.89 ± 4.08 µmol/L, P < 0.001). The frequency of homozygous (TT) genotype in MTHFR C677T mutation was significantly higher in patients with AAA than that in control subjects (19.4 % vs. 11.9 %, P = 0.002). The fasting Hcy correlated negatively with folate (AAA: r = - 0.311, P < 0.01; CONTROL: r = - 0.348, P < 0.01). The aneurysm size was significantly greater (P < 0.001) in patients with hyperhomocysteinemia than that in patients with normal Hcy plasma levels. The size of the AAA had a linear correlation with the plasma Hcy level (r = 0.286; P< 0.001). CONCLUSIONS: Serum folate deficiency and hyperhomocysteinemia were associated with an increased risk of AAA in Northeast China. The homozygous (TT) genotype of MTHFR gene mutation may be a crucial hereditary risk factor in AAA.

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.

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.

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.