Methylenetetrahydrofolate Reductase Gene Mutation Research Articles

Navigating thrombotic terrain: unveiling a novel homocystinuria mutation associated with thrombophilia in a 16 year old

BackgroundThrombophilia is characterised by an abnormality of blood coagulation that increases thrombosis. Homocystinuria encompasses a group of disorders marked by increased levels of homocysteine and other amino acids detectable in the bloodstream and urine. Conversely, homocystinuria due to methylenetetrahydrofolatereductase (MTHFR) deficiency, a rarer disorder, stems from impaired folate metabolism due to deficient MTHFR enzyme.Case presentationA 16-year-old boy presented with walking difficulties, headaches, and thrombotic events, thrombophilia workup led to a diagnosis of homocystinuria due to a novel mutation in MTHFR gene. Anticoagulant therapy was initiated which showed clinical improvement, but financial constraints hindered follow-up.ConclusionsThis case highlights the complexities of diagnosing and treating paediatric thrombophilia, particularly in resource-limited settings. Notably, the identified homozygous autosomal recessive (AR) missense variation in the MTHFR gene (Exon 4—c582C>G) represents a novel mutation, suggesting the ongoing significance of genetic research in elucidating the underlying mechanisms of thrombotic disorders.

Diagnosis and treatment of venous thromboembolism during pregnancy relate to genetic polymorphism.

Previous research had shown that age, a positive family history, comorbidities, major surgical operations, gestation, and use of several medications could increase the incidence of venous thromboembolism (VTE). With the development of medical and clinical individualized treatment, many people exposed to above risk factors did not develop VTE, suggested that genetic factors are also involved in the development of VTE. In this review, we aim to summarize VTE diagnosis and treatment in pregnancy women related to gene polymorphism. A comprehensive electronic search using PubMed, MEDLINE, EMBASE and Web of Science was conducted to find relevant journal articles with key search terms including: "pregnancy OR pregnant," "venous thromboembolism OR VTE," "deep vein thrombosis OR DVT," "pulmonary embolism OR PE," and "genetic OR gene." Prominent publications from establishment of database till present were analysed to achieve a deeper understanding of VTE during pregnancy relate to genetic polymorphism, and the information was then collated to form this review. The literature review revealed that inherited thrombophilia significantly associated with the development of VTE, especially the factor V Leiden (FVL) and prothrombin gene mutation (PGM). Furthermore, the role of methylenetetrahydrofolate reductase (MTHFR) gene mutation in the development of pregnancy-related VTE remains controversial, further study is required. In the present study, Marburg I polymorphism (G511E), c.1538G>A and c.1601G>A in Factor V (FV), JAK2V617F mutation were reported as an independent risk factor for VTE, there is no sufficient evidence to confirm the gene mutation is related to VTE during pregnancy, these factors appearing as another promising potential diagnostic marker of VTE during pregnancy. Besides, the dosages of heparin in the treatment of VTE during pregnancy need be adjusted according to gene polymorphism of these population, particularly FVL or PGM carriers, and this area is not studied deeply, it is worth further study. Inherited thrombophilia significantly associated with the development of VTE, especially the FVL and PGM, however the relation between MTHFR gene mutation and pregnancy-related VTE remains controversial, further study is needed. In addition, the dosages of heparin in the treatment of VTE during pregnancy suggested to adjusted based on gene polymorphism in FVL and PGM, and establish better prediction models is a direction of future research.

The Contribution of Inherited Thrombophilia to Venous Thromboembolism in Cancer Patients.

Although the relationship between venous thromboembolism (VTE) and cancer has been a subject of study, knowledge of the contribution of thrombophilia to thrombosis in patients with cancer is still very limited. The aim of this article is to collect present knowledge on the contribution of inherited thrombophilia to VTE in cancer patients. We performed a search in Google Scholar and PubMed and selected 21 from 76 returned articles. Then we made a narrative review of the selected articles. We describe 11 studies on the contribution of inherited thrombophilia to VTE in cancer patients in general and 10 on that contribution in specific types of cancer: 1 in colorectal cancer, 4 in breast cancer, 1 in gynecologic cancer and 4 in hematopoietic malignancies. All studies investigate the relation of factor V Leiden (FVL) to VTE, 13 that of the prothrombin G20210A mutation (PTG20210A) and 7 studies also investigate other inherited thrombophilias, such methylenetetrahydrofolate reductase gene mutations, although only 2 investigate the contribution of deficiencies of the natural anticoagulants. Studies are very heterogeneous, in design and sample size and conclusions differ considerably. There is no consensus on the contribution of inherited thrombophilia to VTE in cancer patients except for acute lymphoblastic leukemia in children. Probably, that contribution is not the same for all types of cancer and more studies are needed to bring more knowledge on this subject.

Evaluation of acquired and hereditary risk factors for the development of thromboembolism in patients with systemic lupus erythematosus.

Although the contribution of antiphospholipid antibodies (aPL) to thrombolembolism in systemic lupus erythematosus (SLE) is well known, there is not enough data on the contribution of various hereditary thrombophilic factors. In this study, we aimed to determine acquired and hereditary thrombophilic factors in adult patients with SLE. A total of 93 SLE patients (87 women and 6 men) were included. Data on clinical, demographic and laboratory characteristics, and disease activity scores (SLEDAI) of the patients were evaluated. The patients were analyzed with a screen, including lupus anticoagulant, anticardiolipin antibodies (aCL), antithrombin III, protein C, protein S, and homocysteine levels; factor V Leiden ( FVL ), methylenetetrahydrofolate reductase ( MTHFR ) and prothrombin G20210A gene mutations. A total of 23 thromboembolic events were reported in 17 (18.3%) of the patients. The frequency of pregnancy complications and SLEDAI scores were significantly higher in SLE patients who had a thromboembolism event ( P < 0.05). Thromboembolism was detected in 12 (32.4%) of 37 patients with positive aPL antibody and 5 (8.9%) of 56 patients with negative aPL antibody ( P = 0.006). In addition, thromboembolism developed in 11 (32.3%) of 34 lupus anticoagulant-positive patients and 6 (10.1%) of 59 lupus anticoagulant-negative patients ( P = 0.012). Moreover, protein C levels were significantly lower in patients who developed thromboembolism ( P < 0.05). Patients with and without thromboembolism were similar in terms of genetic thrombophilia factors ( MTHFR A1298C, MTHFR C677T, FVL and Prothrombin G20210A ) ( P > 0.05). In conclusion, in the current study, some acquired (aPL, lupus anticoagulant and cCL IGG) and hereditary (protein C deficiency) thrombophilic factors were shown to be associated with the development of thrombosis in SLE patients. However, the effect of other hereditary factors on the development of thromboembolism could not be demonstrated. According to the data of this study, genetic screening seems inappropriate in terms of the risk of thromboembolism in patients with SLE.

Review of mendelian randomization studies on age at natural menopause.

Menopause marks the end of the reproductive phase of life. Based on epidemiological studies, abnormal age at natural menopause (ANM) is thought to contribute to a number of adverse outcomes, such as osteoporosis, cardiovascular disease, and cancer. However, the causality of these associations remains unclear. A powerful epidemiological method known as Mendelian randomization (MR) can be used to clarify the causality between ANM and other diseases or traits. The present review describes MR studies that included ANM as an exposure, outcome and mediator. The findings of MR analyses on ANM have revealed that higher body mass index, poor educational level, early age at menarche, early age at first live birth, early age at first sexual intercourse, and autoimmune thyroid disease appear to be involved in early ANM etiology. The etiology of late ANM appears to be influenced by higher free thyroxine 4 and methylene tetrahydrofolate reductase gene mutations. Furthermore, early ANM has been found to be causally associated with an increased risk of osteoporosis, fracture, type 2 diabetes mellitus, glycosylated hemoglobin, and the homeostasis model of insulin resistance level. In addition, late ANM has been found to be causally associated with an increased systolic blood pressure, higher risk of breast cancer, endometrial cancer, endometrioid ovarian carcinoma, lung cancer, longevity, airflow obstruction, and lower risk of Parkinson's disease. ANM is also a mediator for breast cancer caused by birth weight and childhood body size. However, due to the different instrumental variables used, some results of studies are inconsistent. Future studies with more valid genetic variants are needed for traits with discrepancies between MRs or between MR and other types of epidemiological studies.

Association of MTHFR polymorphism, folic acid and vitamin B12 with serum homocysteine levels in pregnant women.

Homocysteine is known to be associated with adverse vascular and metabolic effects, as well as pregnancy complications. Its serum levels are influenced by the function of the enzyme methylenetetrahydrofolate reductase (MTHFR) and the dietary intake of folic acid, vitamin B12, and methionine. In this cross-sectional study, we investigated the association of genetic polymorphisms of the MTHFR gene with vitamin status in pregnant women during mandatory folic acid supplementation. The study included 102 pregnant women between 24 and 28 weeks of gestation who were attending regular outpatient examinations at the maternity clinic. Homocysteine, folic acid, vitamin B12 levels, and MTHFR gene polymorphisms (C677T and A1298C) were analyzed. Significant associations were found between vitamin B12 and folic acid levels with homocysteine (P < 0.001), with lower serum levels of these vitamins being associated with higher homocysteine levels. Surprisingly, there was no significant association between MTHFR genetic polymorphisms and serum homocysteine levels, likely attributed to the supplementation of folic acid and vitamin B12 in vitamin supplements for pregnant women, which counteracts the effect of the mutation. Remarkably, a high prevalence of MTHFR gene mutations was found, with the C677T polymorphism present in 56.9% and the A1298C polymorphism in 87.2% of pregnant women. These findings emphasize the importance of adequate folic acid and vitamin B12 intake during pregnancy to regulate homocysteine levels. Although the MTHFR gene mutations were highly prevalent, their influence on homocysteine levels in this population appears to be mitigated by vitamin supplementation. Further research is warranted to explore the impact of these mutations on other aspects of pregnancy outcomes. The trial is registrated at Clinicaltrail.gov (NCT04952324).

Association of methylenetetrahydrofolate reductase (MTHFR) rs1801133 (677C>T) gene polymorphism with ischemic stroke risk in different populations: An updated meta-analysis.

Background: Recently, increasing evidence has implicated methylenetetrahydrofolate reductase (MTHFR) gene mutation as a risk factor for ischemic stroke (IS) in the general population. However, studies have been inconclusive and lack evidence on specific populations. We aim to determine whether the rs1801133 (NC_000001.11 (MTHFR):g. 677C>T (p.Ala222Val) variant, we termed as MTHFR rs1801133 (677C>T), is linked to an increased risk of IS in different age groups and ancestry groups. Methods: The literature relevant to our study was found by searching the PubMed, Cochrane Library, Web of Science, EMBASE, and CNKI databases. A random effect model analysis was used to calculate the pooled odds ratio (OR) and 95% confidence interval (CI) to evaluate any possible association. We conducted a subgroup analysis based on the age and ancestry groups of the included populations. Results: As of March 2022, 1,925 citations had been identified in electronic databases, of which 96 studies involving 34,814 subjects met our eligibility criteria. A strong link was found between IS and the MTHFR gene rs1801133 (677C>T) polymorphism in all genetic models [dominant genetic model (OR = 1.47; 95%CI = 1.33-1.61; p < 0.001), recessive genetic model (OR = 1.52; 95%CI = 1.36-1.71; p < 0.001), heterozygous model (OR = 1.36; 95%CI = 1.24-1.48; p < 0.001), homozygous model (OR = 1.82; 95%CI = 1.58-2.11; p < 0.001), and T allelic genetic model (OR = 1.37; 95%CI = 1.27-1.48; p < 0.001)]. Further subgroup analyses indicated that the MTHFR rs1801133 (677C>T) variant may increase the risk of IS in Asian, Hispanic, or Latin population, middle-aged, and elderly populations (p < 0.001). Conclusion: Our results implied that mutation of the T allele of MTHFR rs1801133 (677C>T) could be a risk factor for IS. A significant association was found among Asian, Hispanic, or Latin population, middle-aged, and elderly people.

Methylene tetrahydrofolate reductase gene mutation and methotrexate toxicity in children with acute leukemia

Methylene tetrahydrofolate reductase gene mutation and methotrexate toxicity in children with acute leukemia

Hydropneumothorax – Rare presentation of pulmonary embolism with methylenetetrahydrofolate reductase mutation with hyperhomocysteinemia

Pulmonary embolism (PE) is a relatively common cardiovascular event with high early mortality rates. Many risk factors play a role in the causation of PE including acquired as well as inherited. Methylenetetrahydrofolate reductase (MTHFR) gene mutation is one of the inherited etiologies for PE which cause hyperhomocysteinemia which can lead to PE. This in turn can result in secondary complications such as pneumothorax or hydropneumothorax, which are rare presentations of PE. Hereby, we present this unique case of a 17-year-old boy who presented with a hydropneumothorax which on further evaluation was found to be a complication of bilateral PE which was due to hyperhomocysteinemia with MTHFR A1298C mutation. Hence, we present this unique case with rare presentation as well as rare etiology for PE. This shows the significance for considering PE as one of the differentials in situations such as cavitations, pneumo or hydropneumothoraces, and hyperhomocysteinemias.

Novel compound heterozygous mutations of MTHFR Gene in a Chinese family with homocystinuria due to MTHFR deficiency

BackgroundHomocystinuria due to methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessive disorder. The purpose of this study is to expand the mutation site of the MTHFR gene and provide genetic counseling for this family.MethodsA couple came to our hospital for pre-pregnancy genetic counseling. We collected the family history and detailed clinical information, then performed whole-exome sequencing, and analyzed the pathogenicity of the candidate mutations.ResultsWe found that the father of the proband had homocystinuria, the proband and his brother had low blood methionine levels at birth, and the brain MRI showed brain dysplasia. The third fetus was found to have a broadened triangle of the bilateral ventricle at 19 weeks of pregnancy. The compound heterozygous variants of c.602 A > C (p.His201Pro) and c.1316T > C (p.Leu439Pro) of the MTHFR gene in the first three fetuses were found by whole-exome sequencing. The heterozygous c.602 A > C variant of the MTHFR gene is a novel missense variant that has been submitted to the ClinVar with Variation ID 992,662.ConclusionIn consideration of the clinical phenotype, family history, and result of genetic testing, we speculated that both patients may have homocystinuria due to MTHFR deficiency. Homocystinuria due to MTHFR deficiency caused by compound heterozygous mutations composed of the MTHFR gene in this family may be associated with cerebral atrophy and cerebral dysplasia. The novel compound heterozygous mutations broaden the mutation spectrum of the MTHFR gene and enhance the application of genetic counseling and carrier screening in rare diseases.

Successful Living Donor Kidney Transplantation in a Patient with MTHFR Deficiency and Heparin-Induced Thrombocytopenia: A Case Report

Perioperative anticoagulation in a kidney transplant recipient with heparin-induced thrombocytopenia is challenging due to paradoxical hypercoagulability. A 49-year-old man with end-stage kidney disease and a previous stroke history was referred for living donor kidney transplantation. After the fifth dialysis session, the platelet count decreased to 10,000/μL, and heparin was immediately discontinued. Five days later, pulmonary thromboembolism with deep vein thrombosis was identified. Anti-heparin PF4 antibody, elevated serum homocysteine, and methylenetetrahydrofolate reductase gene mutations were discovered. Subsequent coronary angiography revealed three-vessel disease. Apixaban, folate, aspirin, and clopidogrel were administered and an inferior vena cava filter was implanted. Thereafter, coronary artery bypass graft surgery was performed using argatroban-bridging without complications. Kidney transplantation was performed 3 months later using the argatroban protocol. The graft kidney functioned well without any complications. In conclusion, we successfully conducted kidney transplantation in a thrombophilic patient with a methylenetetrahydrofolate reductase deficiency and heparin-induced thrombocytopenia by establishing an individualized perioperative anticoagulation protocol.

A Study of the MTHFR Gene Prevalence in a Rural Tennessee Opioid Use Disorder Treatment Center Population.

Background: Opioid Use Disorder (OUD) has been linked to dopamine and the neurological reward centers. Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in the production of many neurotransmitters such as dopamine. As such, MTHFR variants that lead to decreased production of neurotransmitters may play a role in OUD. However, lacunae exist for characterizing the prevalence of the MTHFR mutations in an OUD population. The objective of this study was to determine prevalence of the MTHFR gene mutations in a rural Tennessean population with OUD. Methods: This study was a retrospective cohort of individuals with OUD that evaluated the prevalence of MTHFR variants. Patients were categorized as normal, homozygous C677T, heterozygous C677T, homozygous A1298C, or heterozygous A1298C. The primary outcome was a qualitative comparison of the prevalence of each of the MTHFR variants in our cohort to the publicly reported MTHR polymorphism prevalence. Secondary outcomes include race and ethnicity differences as well as stimulant use differences for each of the variants. Results: A total of 232 patients undergoing care for opioid use disorder were included in the study. Of those included, 30 patients had a normal MTHFR allele and 202 had a variant MTHFR allele. Overall, the prevalence of any MTHFR variant was 87.1% (95% CI 82.6–91.4%). When comparing those with a normal MTHFR allele to those with any MTHFR variant, there was no difference in age, sex, race and ethnicity, or stimulant use. Conclusion: The overall prevalence of MTHFR variants in patients with opioid use disorders is high.

Ordering Patterns of Thrombophilia Testing and Its Appropriateness

BackgroundDespite society recommendations to limit thrombophilia testing, this testing is often sent inappropriately. The results of thrombophilia testing frequently do not affect management. Additionally, interpretation of thrombophilia testing is confounded by acute thrombosis, anticoagulation (AC) therapy, and other medical comorbidities. Incorrect test selection is also a source of unnecessary testing [i.e. Factor V (FV) activity level instead of Factor V Leiden (FVL)].The aim of our study was to assess ordering patterns for thrombophilia testing by qualifying the number of tests, identifying the requesting services, and assessing the appropriateness of testing.MethodsThis was a retrospective study of thrombophilia testing performed at LAC+USC Medical Center, Los Angeles, CA from January 1, 2019 to December 31, 2019. A laboratory query of thrombophilia testing was performed to identify eligible adult patients who received thrombophilia testing without a prior confirmed thrombophilia. Thrombophilia testing included: FVL and prothrombin 20210 gene mutations; activated protein C (APC) resistance; antithrombin, or protein C or S activity levels; and antiphospholipid syndrome (APS) evaluation with lupus anticoagulant, cardiolipin (CL) immunoglobulins IgM/G, and beta-2 glycoprotein (b2gp) IgM/IgG; and JAK2 V617F mutation. Homocysteine (HC) levels and methylenetetrahydrofolate reductase (MTHFR) gene mutation testing were considered to have limited clinical utility. FV activity and phosphatidylserine IgM/IgG were considered incorrect tests.The electronic medical record was reviewed for clinical history, indication for testing, requesting service, and appropriateness. The criteria for defining appropriateness were determined based on major society guidelines and literature review. The main criteria are summarized here. Testing was considered inappropriate for a provoked venous thromboembolism (VTE) or stroke/transient ischemic attack (TIA). For unprovoked VTE, testing was considered inappropriate for patients > 45 yo except for APS testing. For non-stroke arterial thrombosis, recurrent pregnancy loss or stillbirth, and diagnostic evaluation of suspected lupus, APS testing only was considered appropriate.Results450 patients underwent thrombophilia testing with a mean age of 42 (range: 18-90); 76% were female and 81% were Hispanic.A total of 1698 thrombophilia tests were sent by 27 services. Testing was done in the following settings: inpatient (40%), outpatient (59%), and emergency department (1%). The mean tests per patient were 3.7 (range: 1-12). The most common requesting services were rheumatology (24%), obstetrics-gynecology (19%), and internal medicine/medicine-pediatrics (14%). Hematology requested 10% of tests.Common indications for testing were VTE (21%), rheumatology-related (25%), pregnancy-related (13%), ischemic stroke/TIA (9%), ocular-related (7%), non-stroke arterial thrombosis (3%), and dermatology-related (4%) (Table 1). 5% (84 tests) were sent for the evaluation of other non-thrombotic conditions. 8% (132 tests) were sent for > 1 indication, such as concurrent arterial and venous events.840 tests (49%) were deemed inappropriate. Common reasons for inappropriate testing included provoked VTE events, stroke/TIA, APS testing after first pregnancy loss, current AC, and duplicate testing (Table 2). APS testing issues included testing for LAC while on AC, incomplete testing (both CL and b2GP not sent), incorrect tests (phosphatidylserine IgM/IgG), and repeat testing < 12 weeks from prior. Incorrect/redundant testing for FVL included: FV activity levels (36 total tests; 9 ordered in additional to FVL and 27 ordered instead of FVL) and APC resistance ordered simultaneously with FVL in 7 patients. Of note, 92 tests were sent for evaluation of non-thrombotic conditions.ConclusionsThrombophilia testing is often done inappropriately. Correct test selection is also a relatively common issue, particularly with APS and FVL testing. Given the large number of services ordering thrombophilia testing at our training hospital and this testing being sent for a variety of reasons, it is unlikely that physician education alone will lead to a substantial or sustained decrease in the number of inappropriate tests. Rather, it may be necessary to restrict at least some thrombophilia testing to certain services. [Display omitted] DisclosuresPiatek: Rigel: Consultancy, Research Funding; Alexion: Consultancy, Research Funding; Apellis: Research Funding; Dova: Consultancy, Speakers Bureau.

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.

A Novel Review of Homocysteine and Pregnancy Complications.

Homocysteine (Hct) is a substance produced in the metabolism of methionine. It is an essential type of amino acid gained from the daily diet. Methylenetetrahydrofolate reductase (MTHFR) gene mutation is related to elevated total homocysteine (tHct) expressions, in particular, among women with low folate intake. Hyperhomocysteinemia (HHct) is caused by numerous factors, such as genetic defects, lack of folic acid, vitamin B6 and B12 deficiency, hypothyroidism, drugs, aging, and renal dysfunction. Increased Hct in peripheral blood may lead to vascular illnesses, coronary artery dysfunction, atherosclerotic changes, and embolic diseases. Compared to nonpregnant women, the Hct level is lower in normal pregnancies. Recent studies have reported that HHct was associated with numerous pregnancy complications, including recurrent pregnancy loss (RPL), preeclampsia (PE), preterm delivery, placental abruption, fetal growth restriction (FGR), and gestational diabetes mellitus (GDM). Besides, it was discovered that neonatal birth weight and maternal Hct levels were negatively correlated. However, a number of these findings lack consistency. In this review, we summarized the metabolic process of Hct in the human body, the levels of Hct in different stages of normal pregnancy reported in previous studies, and the relationship between Hct and pregnancy complications. The work done is helpful for obstetricians to improve the likelihood of a positive outcome during pregnancy complications. Reducing the Hct level with a high dosage of folic acid supplements during the next pregnancy could be helpful for females who have suffered pregnancy complications due to HHct.

Relapse of clinical symptoms of COVID-19 or probable reinfection in a laboratory professional: a case report from Northeast Brazil

Healthcare professionals constitute one of the groups that are most vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Herein, we report the case of a non-overweight and non-smoking 42-year-old woman with thrombophilia due to methylenetetrahydrofolate reductase (MTHFR) gene mutation, hereditary renal cysts, and no history of diabetes or arterial hypertension, who presented the first symptoms between 10 and 17 August 2020, with a SARS-CoV-2-positive naso-oropharyngeal swab by qualitative real-time polymerase chain reaction (RT-PCR). However, the result for SARS-CoV-2 immunoglobulin G (IgG) was non-reactive 41 days after (21 September 2020) the onset of symptoms. Nevertheless, on 7 October 2020 (57 days after the first symptoms), the patient presented new symptoms suggestive of COVID-19, with another SARS-CoV-2-positive RT-PCR result, and on 21 October 2020, SARS-CoV-2 immunoglobulin G was positive. Considering this, we interrogated the results to determine whether the case was reinfection or reactivation. This outcome highlights the importance of surveillance over relapses or reinfections.

Correlation between total homocysteine and cerebral small vessel disease: A Mendelian randomization study.

Cerebral small vessel disease (CSVD) is a clinical imaging syndrome with diverse etiology. Total homocysteine (HCY) level might increase the risk of myocardial and cerebral infarction by damaging the vascular endothelium. We aimed to explore the correlation between total HCY and CSVD imaging burden, based on Mendelian randomization methods. A total of 1,023 participants of the Shunyi study, a population-based cohort study, were included. Vascular risk factors, total HCY levels and methylenetetrahydrofolate reductase (MTHFR) gene mutations (C677T and A1298C) were examined. CSVD imaging markers, including lacunes, cerebral microbleeds, white matter hyperintensity, enlarged perivascular space and brain parenchymal fraction (BPF) were also assessed. Mutations of C677T were significantly correlated with increased total HCY levels (CC→TT: β=0.28, p<0.0001), while mutations of A1298C were correlated with decreased total HCY levels (AA→AC: β=-0.13, p<0.0001; AA→CC: β=-0.25, p=0.004). In the Mendelian randomization study, the C677T genotype was significantly associated with lacunes (CC→CT: odds ratio [OR]2.76, p=0.008; CC→TT: OR 2.50, p=0.018), and the A1298C genotype was significantly correlated with BPF (AA→CC: β=1.32, p=0.015). Similarly, in multivariate regression analysis, total HCY levels were significantly correlated with lacunes (OR2.14, p<0.0001) and negatively correlated with BPF (β=-0.55, p=0.004). Age, sex and vascular risk factors were adjusted for. Total HCY level was correlated with imaging burden of CSVD, especially with lacunes and brain volume loss. For individuals with risk genetic predisposition, enhanced homocysteine-lowering strategies might be necessary to reduce the risk and progress of CSVD.

Association of three missense mutations in the homocysteine-related MTHFR and MTRR gene with risk of polycystic ovary syndrome in Southern Chinese women

BackgroundThe etiology between homocysteine and polycystic ovary syndrome (PCOS) is unclear. In humans, the level of homocysteine is mainly affected by two enzymes: methylene tetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR). While the activity of these two enzymes is mainly affected by three missense mutations, namely C677T (MTHFR), A1298C (MTHFR), and A66G (MTRR). This study aims to examine the association between the three missense mutations and PCOS and investigate whether the three missense mutations exerted their effect on PCOS by affecting the homocysteine level.MethodsA case-control study was designed, comprising 150 people with PCOS and 300 controls. Logistic regression analysis was used to assess the association between the three missense mutations and PCOS. Linear regression analysis was used to assess the association between the three missense mutations and the homocysteine level. Mediation analysis was used to investigate whether the three missense mutations exerted their effect on PCOS by affecting the homocysteine level.ResultsFollowing adjustments and multiple rounds of testing, MTHFR A1298C was found to be significantly associated with PCOS in a dose-dependent manner (compared to AA, OR = 2.142 for AC & OR = 3.755 for CC; P < 0.001). MTRR A66G was nominally associated with PCOS. Mutations in MTHFR A1298C and MTRR A66G were significantly associated with the homocysteine level. Mediation analysis suggested the effect of MTHFR A1298C on PCOS was mediated by homocysteine.ConclusionsMTHFR A1298C and MTRR A66G were associated with PCOS, and MTHFR A1298C might affect the risk of PCOS by influencing the homocysteine level.

Association between serum homocysteine levels and methylene-tetrahydrofolate-reductase gene polymorphism in patients with stroke: A study from a tertiary care teaching hospital from Central India

Background: Hyperhomocysteinemia (HHcy) is a well-established risk factor for vascular thrombosis leading to stroke. Homocysteine (Hcy) is mainly synthesized in the methionine cycle, and it is an intermediate during the conversion of methionine to cysteine. HHcy can develop by polymorphism of several enzymes like methylene-tetrahydrofolate-reductase (MTHFR) mutation and due to deficiency of co-factor Vitamins such as B12, B6, and folic acid. This study was planned to see the association between HHcy and MTHFR gene polymorphism in patients with stroke in populations from central India. Methods: Seventy-two patients diagnosed with stroke aged 18 years and above who met the inclusion criteria were selected. Hcy level and MTHFR mutation were identified among patients of stroke. Results: Forty-two patients (58.33%) were diagnosed with acute ischemic stroke as compared to cerebral venous thrombosis (30, 41.66%) from a total of 72 patients. The statistical analysis projected that the HHcy diagnosed among more (45, 62.5.0%) cases with stroke who had aged ≤45 years as compared to cases who had aged >45 years (17, 23.6%). None of our patients tested positive for either CT (Heterozygous) or TT(Homozygous) genotypes. Conclusions: HHcy is not associated with MTHFR gene mutation in our study group, and this possibly is related to the deficiency of co-factors in Hcy metabolism. Young age group stroke patients have higher Hcy levels.

Methylene tetrahydrofolate reductase C677T polymorphism in Korean livedoid vasculopathy patients

Methylene tetrahydrofolate reductase C677T polymorphism in Korean livedoid vasculopathy patients