MTHFR gene polymorphism, homocysteine and cardiovascular disease

Association of MTHFR and DNMT-1 Gene Polymorphisms with Acute Coronary Syndrome in Patients Admitted to the Emergency Department

Background/Objectives: Acute coronary syndrome (ACS) is a critical cardiovascular condition influenced by genetic and environmental factors. Polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and deoxyribonucleic acid methyltransferase-1 (DNMT-1) genes are linked to cardiovascular diseases, yet their specific roles in ACS pathogenesis remain unclear. This study examines the association of MTHFR C677T and DNMT-1 +32204 A/G polymorphisms with ACS and their potential contribution to genetic risk profiling. Methods: A case-control study was conducted with 212 participants, including 106 ACS patients and 106 controls. Peripheral blood samples were collected and analyzed to determine genotypic and allelic frequencies using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Statistical analyses were performed to assess associations between gene polymorphisms and ACS risk. Results: The MTHFR C677T polymorphism showed a strong association with ACS. The CC genotype significantly increased risk (OR: 7.34; 95% CI: 2.28-23.6; p < 0.001), while the C allele was also associated with higher susceptibility (OR: 2.21; 95% CI: 1.46-3.35; p < 0.001). Conversely, the T allele exhibited a protective effect, being more frequent in controls (62.9% vs. 37.1% in ACS; p = 0.000). Elevated troponin I levels in ACS patients with the TT genotype (p = 0.025) suggested a link between MTHFR variants and disease severity. However, DNMT-1 +32204 A/G polymorphisms showed no significant association with ACS risk. Conclusions: The MTHFR C677T polymorphism influences ACS susceptibility, with the CC genotype as a risk factor and the T allele offering potential protection.

Impacts of Methylenetetrahydrofolate Reductase Genotypes on Hallux Valgus

BACKGROUND/AIM

Hallux valgus (HV) is the most common deformity of the forefoot. Although HV has been strongly associated with a family history, its genetic underpinnings remain unclear. Few studies have examined the relationship between folic acid metabolism, which is critical in normal bone development, and HV. The study aimed to investigate the contribution of methylenetetrahydrofolate reductase (MTHFR) genotypes to the risk of HV.

MATERIALS AND METHODS

The MTHFR rs1801133 and rs1801131 genotypes were analyzed in 150 patients with HV and 600 controls without HV, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

The results highlighted a significant difference in the genotypic frequency distributions of MTHFR rs1801133 between the HV cases and non-HV controls (p for trend=0.0024). Specifically, individuals with the homozygous TT genotype at MTHFR rs1801133 exhibited a 2.57-fold increased risk of HV (95% confidence interval=1.49-4.42, p=0.0009). However, those with the CT genotype did not show an elevated risk. Stratified analysis showed no correlation between MTHFR rs1801133 genotypic distributions and different age groups (below or above 51 years) or sex (both p>0.05). Furthermore, no associations were identified between MTHFR rs1801133 and height, weight, or body mass index in relation to HV risk.

CONCLUSION

The TT genotype of MTHFR rs1801133 is associated with an increased risk of HV. Subgrouping HV patients based on their MTHFR genotypes and related comorbidities, such as rheumatoid arthritis, may offer a new approach to diagnosis.

Association of Methylenetetrahydrofolate Reductase (MTHFR) Polymorphism with Osteosarcoma in a Mexican Population

The methylenetetrahydrofolate reductase (MTHFR) gene 677C➔T polymorphism is capable of altering folate metabolism and can modify certain neoplasia risk. Reports have suggested that folate can have an influence on bone development and so it is of interest to know if the MTHFR 677C➔T polymorphism is associated with the malignant transformation process of this tissue. The polymorphism was determined in 55 patients with osteosarcoma and in 180 healthy individuals. Compared with C/T+C/C genotypes, a 3.7-fold reduction in osteosarcoma probability is possible with the T/T genotype (OR 0.27, CI 95% 0.07-0.82). Undoubtedly, further studies, utilizing large samples and carried out on different populations, are necessary to confirm these results.

The dos, don'ts, and nuances of thrombophilia testing

Considerable progress has been made in elucidating genetic and biologic risk factors for venous thromboembolism (VTE). Despite being able to identify heritable defects in a substantial proportion of patients with VTE, testing has not, in general, proven useful in management. Despite efforts to reduce inappropriate testing, it often falls to the hematologist to consult on patients having undergone thrombophilia testing. Through a series of cases, we discuss how D-dimer testing can be helpful in VTE recurrence risk stratification in younger women as well as how to approach patients with persistently elevated D-dimer levels in the absence of thrombosis. While elevated factor VIII coagulant activity levels are a significant risk factor for a first episode of VTE, its biologic basis is not fully understood, and studies have not shown it to be a useful predictor of recurrence. Abnormal results of genetic tests for methylene tetrahydrofolate reductase or plasminogen activator 1 promoter polymorphisms may be encountered, which carry little if any thrombotic risk and should never be ordered. We also discuss protein S deficiency, the most difficult of the hereditary thrombophilias to diagnose due to a wider "normal" range in the general population as compared with protein C, the presence of both free and bound forms in plasma, and the characteristics of the various assays in use. We also present a rare type of protein C deficiency that can be missed by functional assays using an amidolytic rather than a clotting end point.

MTHFR gene polymorphisms and susceptibility to myocardial infarction: Evidence from meta-analysis and trial sequential analysis

Background

This meta-analysis aimed to provide a comprehensive assessment of the association between Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms, specifically C677T and A1298C, and the susceptibility to myocardial infarction (MI).

Methods

A systematic literature search was conducted in MEDLINE, Web of Science, and Scopus until April 2023 to identify studies investigating the relationship between MTHFR gene polymorphisms (C677T and A1298C) and the risk of MI.

Results

The analysis included 66 studies involving 16,860 cases and 20,403 controls for the C677T polymorphism and 18 studies comprising 3162 cases and 3632 controls for the A1298C polymorphism. Significant associations were observed between the C677T polymorphism and MI risk in various genetic models: dominant (OR = 1.16, 95 % CI = 1.06-1.28, P = 0.008), recessive (OR = 1.20, 95 % CI = 1.12-1.28, P < 0.001), allelic (OR = 1.13, 95 % CI = 1.06-1.21, P < 0.001), TT vs. CC (OR = 1.19, 95 % CI = 1.05-1.36, P < 0.001), and CT vs. CC (OR = 1.11, 95 % CI = 1.02-1.21, P = 0.01). Furthermore, an overall analysis indicated a marginally significant association between the A1298C polymorphism and MI risk in the recessive model (OR = 1.27, 95 % CI = 1.06-1.51, P = 0.008), allelic model (OR = 1.18, 95 % CI = 1.01-1.39, P = 0.03), and CC vs. AA model (OR = 1.22, 95 % CI = 1.01-1.47, P = 0.04). Meta-regression analysis revealed that none of the potential factors contributed to the observed heterogeneity.

Conclusions

This meta-analysis revealed an association between MTHFR gene C677T and A1298C polymorphisms and the risk of MI.

Plasma homocysteine levels and associated factors in community-dwelling adolescents: the EVA-TYROL study

Background

Homocysteine (Hcy) has been associated with an adverse cardiovascular risk profile in adolescents. Assessment of the association between plasma Hcy levels and clinical/laboratory factors might improve our understanding of the pathogenesis of cardiovascular disease.

Methods

Hcy was measured in 1,900 14- to 19-year-old participants of prospective population-based EVA-TYROL Study (44.3% males, mean age 16.4 years) between 2015 and 2018. Factors associated with Hcy were assessed by physical examination, standardized interviews, and fasting blood analysis.

Results

Mean plasma Hcy was 11.3 ± 4.5 µmol/L. Distribution of Hcy was characterized by extreme right skew. Males exhibited higher Hcy and sex differences increased with increasing age. Univariate associations with Hcy emerged for age, sex, body mass index, high-density lipoprotein cholesterol, and for factors pertaining to blood pressure, glucose metabolism, renal function, and diet quality, whereas the most important multivariate predictors of Hcy were sex and creatinine.

Discussion

Clinical and laboratory factors associated with Hcy in adolescents were manifold, with sex and high creatinine identified as strongest independent determinants. These results may aid when interpreting future studies investigating the vascular risk of homocysteine.

MTHFR c.665C>T and c.1298A>C Polymorphisms in Tailoring Personalized Anti-TNF-α Therapy for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease with a prevalence of 1%. Currently, RA treatment aims to achieve low disease activity or remission. Failure to achieve this goal causes disease progression with a poor prognosis. When treatment with first-line drugs fails, treatment with tumor necrosis factor-α (TNF-α) inhibitors may be prescribed to which many patients do not respond adequately, making the identification of response markers urgent. This study investigated the association of two RA-related genetic polymorphisms, c.665C>T (historically referred to as C677T) and c.1298A>C, in the MTHFR gene as response markers to an anti-TNF-α therapy. A total of 81 patients were enrolled, 60% of whom responded to the therapy. Analyses showed that both polymorphisms were associated with a response to therapy in an allele dose-dependent manner. The association for c.665C>T was significant for a rare genotype (p = 0.01). However, the observed opposite trend of association for c.1298A>C was not significant. An analysis revealed that c.1298A>C, unlike c.665C>T, was also significantly associated with the drug type (p = 0.032). Our preliminary results showed that the genetic polymorphisms in the MTHFR gene were associated with a response to anti-TNF-α therapy, with a potential significance for the anti-TNF-α drug type. This evidence suggests a role for one-carbon metabolism in anti-TNF-α drug efficacy and contributes to further personalized RA interventions.

Genetic analysis of colorectal carcinoma using high throughput single nucleotide polymorphism genotyping technique within the population of Jammu and Kashmir

BACKGROUND

SNP genotyping has become increasingly more common place to understand the genetic basis of complex diseases like cancer. SNP-genotyping through MassARRAY™ is a cost-effective method to quantitatively analyse the variation of gene expression in multiple samples, making it a potential tool to identify the underlying causes of colorectal carcinogenesis.

METHODS

In the present study, SNP genotyping was carried out using Agena MassARRAY™, which is a cost-effective, robust, and sensitive method to analyse multiple SNPs simultaneously. We analysed 7 genes in 492 samples (100 cases and 392 controls) associated with CRC within the population of Jammu and Kashmir. These SNPs were selected based on their association with multiple cancers in literature.

RESULTS

This is the first study to explore these SNPs with colorectal cancer within the J&K population.7 SNPs with a call rate of 90% were selected for the study. Out of these, five SNPs rs2234593, rs1799966, rs2229080, rs8034191, rs1042522 were found to be significantly associated with the current study under the allelic model with an Odds Ratio OR = 2.981(1.731-5.136 at 95% CI); p value = 4.81E-05 for rs2234593,OR = 1.685(1.073-2.647 at 95% CI);; p value = 0.02292 for rs1799966, OR = 1.5 (1.1-2.3 at 95% CI), p value = 0.02 for rs2229080, OR = 1.699(1.035-2.791 at 95% CI); p value = 0.03521 for rs8034191, OR = 20.07 (11.26-35.75); p value = 1.84E-34 for rs1042522 respectively.

CONCLUSION

This is the first study to find the relation of Genetic variants with the colorectal cancer within the studied population using high throughput MassARRAY™ technology. It is further anticipated that the variants should be evaluated in other population groups that may aid in understanding the genetic complexity and bridge the missing heritability.

A Association of MTHFR C677T and MTRR A66G Gene Polymorphisms with Iranian Male Infertility and Its Effect on Seminal Folate and Vitamin B12

Background

The relation between key enzymes in regulation of folate metabolism and male infertility is the subject of numerous studies. We aimed to determine whether 5, 10-methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G genotypes are associated with male infertility in Iranian men and to evaluate its effect on seminal levels of folate and vitamin B12.

Materials and Methods

In this retrospective study, semen and peripheral blood samples were collected from 254 men with oligoasthenoteratozoospermia (OAT) and 77 normozoospermic men who attended Avicenna infertility clin- ic. Single nucleotide polymorphism (SNP) analysis was carried out in genomic DNA by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method for MTHFR C677T and MTRR A66G gene poly- morphisms.

Results

In MTHFR C677T, our founding showed that T carrier was conversely lower in OAT than normozoospermic men (χ²-test=7.245, P=0.02) whereas in MTRR A66G, A and G carrier showed no significant difference between the two groups (χ²-test=1.079, P=0.53). The concentration of seminal folate was not different between normozoospermic (18.83 ± 17.1 ng/ ml) and OAT (16.96 ± 14.2 ng/ml) men (P=0.47). The concentration of vitamin B₁₂ was slightly higher in normozospermic men (522.6 ± 388.1 pg/ml) compared to OAT men (412.9 ± 303.6 pg/ml, P=0.058).

Conclusion

The MTHFR C677T and MTRR A66G have no effect on the concentrations of seminal folate and vitamin B₁₂. The present study showed that two SNPs of MTRR A66G and MTHFR C677T cannot be seen as a risk factor for male factor subfertility.

Influence of genetic polymorphisms in homocysteine and lipid metabolism systems on antidepressant drug response

BACKGROUND

Variation in genes implicated in homocysteine and lipid metabolism systems may influence antidepressant response for patients with major depressive disorder (MDD). This study aimed to investigate whether association of polymorphisms on the MTHFR, ApoE and ApoA4 genes with the treatment response in MDD subjects.

METHODS

A total of 281 Han Chinese MDD patients received a single antidepressant drug (SSRI or SNRI) for at least 6 weeks, among whom 275 were followed up for 8 weeks. Their response to 6 weeks' treatment and remission to 8 weeks' treatment with antidepressant drugs was determined by changes in the 17-item Hamilton Depression Rating Scale (HARS-17) score. Single SNP and haplotype associations with treatment response were analyzed by UNPHASED 3.0.13. Logistic regression analysis was used to explore the interactions between genotypes and gender or drug type on treatment outcome, only those SNPs that had interactional association with gender or drug type were subjected to further stratified analysis.

RESULTS

In total group, the haplotype (C-A) in MTHFR (rsl801133 and rs1801131) and the ApoE rs405509 AA genotype were significantly associated with better efficacy of antidepressants; In gender subgroups, only haplotype (C-A) in MTHFR (rsl801133 and rs1801131) was significantly associated with better efficacy of antidepressants in male subgroup; In drug type subgroup, the haplotype (C-A) in MTHFR (rsl801133 and rs1801131) and haplotype (G-C) in ApoE (rs7412 and rs405509) were associated with better efficacy of antidepressants in SNRI treated subgroup; The ApoA4 rs5092 G allele and GG genotype were associated with worse efficacy of antidepressants in SNRI treated subgroup.

CONCLUSIONS

Genetic polymorphisms in homocysteine and lipid metabolism systems are associated with antidepressant response, particularly for the interactions of the certain genetic with gender or drug type.

The frequency of Raynaud’s phenomenon in patients with methylenetetrahydrofolate reductase gene mutation and hyperhomocysteinemia

Background/aim

Raynaud’s phenomenon (RP) is not a rare health problem; global prevalence is about 3%–20%. Etiology and pathophysiology of this pathology has not been clarified. There are many precipitating factors resulting in RP. Hyperhomocysteinemia resulting from methylenetetrahydrofolate reductase (MTHFR) gene mutationmay have a role in its etiology. The aim of this study was to observe the frequency of RP in patients with MTFHR gene mutation and hyperhomocysteinemia. Possible relationships among vitamin B12, folic acid, complete blood count (leukocytes and platelets), and c-reactive protein levels and RP were also analyzed.

Materials and methods

A total of 388 patients admitted to the internal medicine, hematology, and obstetric clinics of a university hospital between January 2012 and April 2013 ranging in age from 21 to 83 (mean age 38.16 ± 13.1) were enrolled in the study. Eighty-five (21.9%) of the patients were male and 303 (78.1%) were female. MTHFR gene mutation was analyzed in 388 patients; 52 (13.4%) were homozygous, 275 (70.9%) were heterozygous, and 61 (15.7%) were found to be negative for the MTHFR gene mutation and accepted as a control group. Vitamin B12, folic acid, complete blood count (leukocytes and platelets), and c-reactive protein levels were also analyzed.

Results

Homocysteine levels were higher in both heterozygous and homozygous groups (P < 0.05). RP was more frequently observed in patients with elevated homocysteine levels (P < 0.05; X2 = 14.51). There was no significant relationship in other parameters studied.

Conclusion

RP was more frequently observed in the groups with the MTHFR mutation and hyperhomocysteinemia. Serum homocysteine levels in patients with RP may be helpful for diagnosis.

Methylenetetrahydrofolate Reductase (MTHFR) C677T Polymorphism and Subacute Combined Degeneration: Revealing a Genetic Predisposition

Vitamin B12 deficiency is regarded as the prevailing cause of subacute combined degeneration of the spinal cord (SCD). Nevertheless, the genetic predisposition to SCD remains unclear. The aim of this study was to explore the association between methylenetetrahydrofolate reductase gene (MTHFR) C677T polymorphism and SCD. We investigated MTHFR C677T polymorphism in SCD patients and found that the distribution of MTHFR C677T genotypes was significantly different between SCD patients and age-matched controls. Furthermore, the T allele frequency was markedly increased in SCD compared with the controls. In addition, the plasma homocysteine concentrations in subjects with the TT genotype were significantly elevated compared to those with the CC genotype. Logistic regression analysis results revealed that the MTHFR C677T genotype (TT vs. CT and CC) and vitamin B12 deficiency were risk factors for SCD. Our findings indicate that the T allele of the MTHFR C677T confers a strong genetic predisposition to SCD and provide evidence of an association between MTHFR C677T polymorphism and SCD. These data reveal a potential mechanism underlying SCD.

The Effects of Homocysteine on the Skeleton

PURPOSE OF REVIEW

Homocystinuria is a congenital metabolic disorder in which cystathionine β-synthase deficiency results in a prominent increase in homocysteine (serum levels > 100 μM), causing mental retardation, atherosclerotic cerebral infarction, and osteoporosis accompanied by fragility fractures. Encountering a case with excessive homocysteinemia such as that seen in hereditary homocystinuria is unlikely during usual medical examinations. However, in individuals who have vitamin B or folate deficiency, serum homocysteine concentrations are known to increase. These individuals may also have a polymorphism in methylenetetrahydrofolate reductase, MTHFR (C677T: TT type), which regulates homocysteine metabolism. These changes in homocysteine levels may elicit symptoms resembling those of homocystinuria (e.g., Alzheimer's disease, atherosclerosis, osteoporosis).

RECENT FINDINGS

High serum homocysteine has been shown to have detrimental effects on neural cells, vascular endothelial cells, osteoblasts, and osteoclasts. Homocysteine is also known to increase oxidative stress, disrupt cross-linking of collagen molecules, and increase levels of advanced glycation end products, which results in reduced bone strength through a mechanism that goes beyond low bone density and increased bone resorption. Therefore, high serum homocysteine may be regarded as a factor that can reduce both bone mass and impair bone quality. In this review, we outline the epidemiology and pathophysiology of osteoporosis associated with hyperhomocysteinemia.

Homocysteine and homocysteine-related compounds: an overview of the roles in the pathology of the cardiovascular and nervous systems

Homocysteine, an amino acid containing a sulfhydryl group, is an intermediate product during metabolism of the amino acids methionine and cysteine. Hyperhomocysteinemia is used as a predictive risk factor for cardiovascular disorders, the stroke progression, screening for inborn errors of methionine metabolism, and as a supplementary test for vitamin B₁₂ deficiency. Two organic systems in which homocysteine has the most harmful effects are the cardiovascular and nervous system. The adverse effects of homocysteine are achieved by the action of several different mechanisms, such as overactivation of N-methyl-d-aspartate receptors, activation of Toll-like receptor 4, disturbance in Ca²⁺ handling, increased activity of nicotinamide adenine dinucleotide phosphate-oxidase and subsequent increase of production of reactive oxygen species, increased activity of nitric oxide synthase and nitric oxide synthase uncoupling and consequent impairment in nitric oxide and reactive oxygen species synthesis. Increased production of reactive species during hyperhomocysteinemia is related with increased expression of several proinflammatory cytokines, including IL-1β, IL-6, TNF-α, MCP-1, and intracellular adhesion molecule-1. All these mechanisms contribute to the emergence of diseases like atherosclerosis and related complications such as myocardial infarction, stroke, aortic aneurysm, as well as Alzheimer disease and epilepsy. This review provides evidence that supports the causal role for hyperhomocysteinemia in the development of cardiovascular disease and nervous system disorders.

Vitamin B₆ and Its Role in Cell Metabolism and Physiology

Vitamin B₆ is one of the most central molecules in cells of living organisms. It is a critical co-factor for a diverse range of biochemical reactions that regulate basic cellular metabolism, which impact overall physiology. In the last several years, major progress has been accomplished on various aspects of vitamin B₆ biology. Consequently, this review goes beyond the classical role of vitamin B₆ as a cofactor to highlight new structural and regulatory information that further defines how the vitamin is synthesized and controlled in the cell. We also discuss broader applications of the vitamin related to human health, pathogen resistance, and abiotic stress tolerance. Overall, the information assembled shall provide helpful insight on top of what is currently known about the vitamin, along with addressing currently open questions in the field to highlight possible approaches vitamin B₆ research may take in the future.

Potential genetic polymorphisms predicting polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogenous endocrine disorder with typical symptoms of oligomenorrhoea, hyperandrogenism, hirsutism, obesity, insulin resistance and increased risk of type 2 diabetes mellitus. Extensive evidence indicates that PCOS is a genetic disease and numerous biochemical pathways have been linked with its pathogenesis. A number of genes from these pathways have been investigated, which include those involved with steroid hormone biosynthesis and metabolism, action of gonadotropin and gonadal hormones, folliculogenesis, obesity and energy regulation, insulin secretion and action and many others. In this review, we summarize the historical and recent findings in genetic polymorphisms of PCOS from the relevant publications and outline some genetic polymorphisms that are potentially associated with the risk of PCOS. This information could uncover candidate genes associating with PCOS, which will be valuable for the development of novel diagnostic and treatment platforms for PCOS patients.

Single Nucleotide Polymorphisms in Key One-Carbon Metabolism Genes and Their Association with Blood Folate and Homocysteine Levels in a Chinese Population in Yunnan

OBJECTIVE

One-carbon metabolism (OCM) is essential for DNA synthesis and methylation. Single nucleotide polymorphisms (SNPs) within OCM genes may affect folic acid (FA) metabolism, disrupt homocysteine (Hcy) homeostasis, and increase the risk of disease. This study investigated the relationship between SNPs in key OCM genes and their association with blood FA and Hcy levels in a healthy population in Yunnan, China.

METHODS

Six SNPs within five key OCM genes (MTHFR C677T, MTHFR A1298C, MS A2756G, MTRR A66G, CBS T833C, and SHMT C1420T) were genotyped in 300 healthy volunteers (148 males and 152 females) using polymerase chain reaction/restriction fragment length polymorphism. Blood folate [serum FA (SFA) and red blood cell folate (RBC FA)] and Hcy levels were determined by chemiluminescence immunoassays and enzymatic assays.

RESULTS

Subjects with the MTHFR 677TT genotype had significantly higher Hcy levels and RBC FA concentrations compared with those harboring the MTHFR 677CC/CT genotypes (p < 0.01). Both Hcy and blood FA concentrations were also increased in subjects with MS 2756AA, as well as those within CBS 833TT, when compared with those with MS 2756AG/GG (p < 0.05) and CBS 833TC/CC (p < 0.05) genotypes, respectively. Subjects harboring the combined genotype of MTHFR 677TT and MS 2756AA had a higher Hcy concentration than those carrying other MTHFR and MS combinations (p = 0.002). Similarly, subjects harboring the combination of CBS 833TT with MTHFR 677TT had higher Hcy concentrations than those harboring other CBS and MTHFR combinations (p = 0.011).

CONCLUSIONS

The genotypes involving the MTHFR C677T, MS A2756G, and CBS T833C polymorphisms, including combinations of these genotypes, were the most important factors associated with blood FA and Hcy levels of the investigated SNPs in the OCM genes.

Methylenetetrahydrofolate reductase C677T polymorphism and the risks of polycystic ovary syndrome: an updated meta-analysis of 14 studies

Some studies have reported an association between the Methylenetetrahydrofolate reductase (MTHFR) C667T genetic variant and risk of polycystic ovary syndrome (PCOS), although the results remain controversial. A systematic search was conducted on PubMed, Web of Science, EMBASE, Ovid, Chinese National Knowledge Databases and WanFang databases with relevant keywords. Fourteen studies of sixteen distinct populations involving 1478 PCOS cases and used to conduct a meta-analysis. The T allele was not significantly associated with increased risk of PCOS [OR: 1.08; 95% CI: 0.96–1.21]. In the stratified analysis by ethnicity, the T allele significantly increases risks for the Asian [OR = 1.31; 95% CI: 1.09–1.58] population. No significant associations were detected for the Middle Eastern population [OR = 1.26; 95% CI: 0.96–1.67] and the T allele was found to be protective in the Caucasian population [OR = 0.82; 95% CI: 0.68–0.99]. In conclusion, this meta-analysis suggests that MTHFR C667T variant can increase, decrease, or have no effect on the risks of PCOS depending on the ethnicity.

Influence of food groups on plasma total homocysteine for specific MTHFR C677T genotypes in Chinese population

Scope

It has been demonstrated that a mutation of MTHFR C677T increases plasma total homocysteine (Hcy) concentration and decreases folate. Natural foods can improve Hcy levels, but the effect of certain foods remains undetermined. The aim of this study was to investigate the association between food groups and Hcy, and to explore the correlations between Hcy and dietary folate/vitamin (Vit) B12 for genotype‐specific population.

Methods and results

A total of 4507 adults were enrolled in this study, all of whom underwent physical examinations and genotyping. A dietary recall questionnaire, which assessed the frequency (F) and quantity (Q) of food consumption, was completed by all. For the male CC group, after adjustment for age and BMI, fish (F) was negatively correlated with Hcy; for the male CT group, fish (F) and eggs (F) were negatively associated with Hcy, whereas cereal/wheat (Q) were positively correlated with Hcy; for the male TT group, fish (F), meat (Q), milk (F), and fruits/vegetables (Q) were negatively associated with Hcy, whereas sugar (Q) and salt (Q) were positively associated with Hcy. For the female CC group, fruits/vegetables (Q), eggs (F) and meat (F) were negatively correlated with Hcy, but soy (F) was positively correlated with Hcy; for the female CT group, eggs (F) and meat (Q) were negatively correlated with Hcy, whereas soy (F), fried foods (F) and salt (Q) were positively correlated with Hcy; for the female TT group, fish(F), eggs (F), and fruits/vegetables (F) were negatively associated with Hcy. Furthermore, we found that Hcy was more closely correlated with folate than with Vit B12 for males (CC, CT and TT) and female TT genotype. However, the correlation between Hcy and Vit B12 was stronger for the female CT/CC groups.

Conclusion

Hcy levels were influenced by food groups to varying degrees, which were based on gender and MTHFR C677T genotypes. Hcy levels were more closely correlated with folate for males (CC, CT and TT) and the female TT group, but it was more closely correlated with Vit B12 for the female CT/CC groups.

Search for Correlations Between Genotypes and Electrophysiological Patterns in Migraine: The MTHFR C677T Polymorphism and Visual Evoked Potentials

Interictally, migraineurs have on average a reduction in habituation of pattern-reversal visual evoked potentials (PR-VEP) and in mitochondrial energy reserve. 5,10-Methylenetetrahydrofolate reductase (MTHFR) is involved in folate metabolism and its C677T polymorphism may be more prevalent in migraine. The aim of this study was to search in migraineurs for a correlation between the MTHFR C677T polymorphism and the PR-VEP profile. PR-VEP were recorded in 52 genotyped migraine patients: 40 female, 24 without (MoA), 28 with aura (MA). Among them 21 had a normal genotype (CC), 18 were heterozygous (CT) and 13 homozygous (TT) for the MTHFR C677T polymorphism. Mean PR-VEP N1-P1 amplitude was significantly lower in CT compared with CC, and tended to be lower in TT with increasing age. The habituation deficit was significantly greater in CC compared with TT subjects. The correlation between the cortical preactivation level, as reflected by the VEP amplitude in the first block of averages, and habituation was stronger in CC than in CT or TT.

The MTHFR C677T polymorphism could thus have an ambiguous role in migraine. On one hand, the better VEP habituation which is associated with its homozygosity, and possibly mediated by homocysteine derivatives increasing serotoninergic transmission, may protect the brain against overstimulation. On the other hand, MTHFR C677T homozygosity is linked to a reduction of grand average VEP amplitude with illness duration, which has been attributed to brain damage.

Homocysteine Levels Influence Platelet Reactivity in Coronary Artery Disease Patients Treated With Acetylsalicylic Acid

BACKGROUND

Suboptimal platelet inhibition with antiplatelet treatments is associated with a severe prognosis in patients with coronary artery disease (CAD), and the identification of its determinants is still challenging. Homocysteine elevation has emerged as a prothrombotic factor, influencing coagulative status and endothelial function and potentially modulating platelet aggregation. We therefore aimed to evaluate the effects of homocysteine (Hcy) levels on platelet reactivity in patients receiving acetylsalicylic acid (ASA) with or without ADP antagonists.

METHODS

Patients undergoing coronary angiography and receiving ASA (100-160 mg daily) for >7 days, with or without ADP antagonists, were included. Aggregation tests were performed by multiple electrode aggregometry. Suboptimal platelet inhibition was defined as on-treatment aggregation above the lower limit of normality.

RESULTS

Our population is represented by 508 ASA-treated patients, 406 (80.1%) of whom on dual antiplatelet therapy (ASA and ADP antagonists). Hcy levels above the median (15.1 nmol/mL) were associated with male gender (P = 0.04), hypertension (P = 0.004), hypercholesterolemia (P = 0.03), aging, renal failure (P < 0.001, respectively), previous coronary bypass grafting (P = 0.04), therapy with calcium antagonists (P = 0.04) and diuretics (P = 0.001), and multivessel CAD (P = 0.03). Higher Hcy is directly related with serum creatinine and uric acid (P < 0.001). Suboptimal platelet inhibition was found in 16 patients (3.2%) for ASA and for ADP antagonists in 80 patients (19.7%). Hcy levels significantly affected suboptimal response to ASA, but not to ADP-mediated aggregation. In fact, a linear relationship was found between homocysteine and platelet reactivity after stimulation with arachidonic acid (r = 0.14, P = 0.004) and collagen (r = 0.12, P = 0.02), but not with ADP (r = 0.02, P = 0.77). Moreover, after correction for baseline differences, Hcy above the median was confirmed as an independent predictor of impaired ASA response [adjusted odds ratio (95% confidence interval) = 3.7 (1.08-12.4), P = 0.04].

CONCLUSIONS

Among patients with CAD, elevated homocysteine is an independent predictor of suboptimal response to ASA, but not to ADP antagonists.

Is MTHFR 677 C>T Polymorphism Clinically Important in Polycystic Ovarian Syndrome (PCOS)? A Case-Control Study, Meta-Analysis and Trial Sequential Analysis

BACKGROUND

Optimum efficiency of the folate pathway is considered essential for adequate ovarian function. 677 C>T substitution in the 5, 10-methylene tertrahydrofolatereductase (MTHFR) gene compromises activity of the MTHFR enzyme by about 50%. The significance of correlation between 677C>T substitution and PCOS remains dubious due to the low power of published studies.

METHODS AND RESULTS

We analyzed MTHFR 677 C>T site in ethnically two different PCOS case-control groups (total 261 cases and 256 controls) from India. The data analysis revealed a lack of association between this polymorphism and PCOS [OR = 1.11 (95%CI = 0.71-1.72), P = 0.66]. Group-wise analysis on the basis of ethnicity also revealed no association in any of the ethnic groups [Indo-Europeans, P = 1; Dravidians, P = 0.70]. Homocysteine levels did not differ significantly between cases (15.51 μmol/L, SD = 2.89) and controls (15.89 μmol/L, SD = 2.23). We also undertook a meta-analysis on 960 cases and 1028 controls, which suggested a significant association of the substitution with PCOS in the dominant model of analysis (OR = 1.47 (95%CI = 1.04-2.09), P = 0.032]. Trial sequential analysis corroborated findings of the traditional meta-analysis. However, we found that the conclusions of meta-analysis were strongly influenced by studies that deviated from the Hardy Weinberg equilibrium. A careful investigation of each study and a trial sequential analysis suggested that 677 C>T substitution holds no clinical significance in PCOS in most of the populations.

CONCLUSION

In conclusion, MTHFR 677 C>T polymorphism does not affect PCOS risk in India. The association seen in the meta-analysis is due to an outlier study and studies showing deviation from the Hardy Weinberg equilibrium.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.

Functional variants of gene encoding folate metabolizing enzyme and methotrexate-related toxicity in children with acute lymphoblastic leukemia

Methotrexate (MTX) is commonly used agent in therapy of malignancies, including acute lymphoblastic leukemia (ALL). Based on the literature data it is known that MTX elimination and toxicity can be affected by polymorphisms in genes encoding enzymes involved in MTX metabolism. The aim of our study was to investigate the influence of C677T and A1298C polymorphisms in methylenetetrahydrofolate reductase (MTHFR) gene on MTX-induced toxicity during treatment of children with ALL. We also tried to answer the question whether simultaneous occurrence of these two polymorphisms has a clinical significance. MTHFR polymorphisms were assessed in 47 pediatric ALL patients, treated according to intensive chemotherapy for childhood ALL, ALL IC BFM 2009. Prolonged MTX elimination and higher incidence of toxicity were observed for patients with 677T-1298A haplotype. On the other hand, occurrence of 677C-1298A haplotype had protective effect on MTX clearance and toxicity, that was not observed in carriers of 677C-1298C haplotype. In patients with coexistence of studied variants 677CT/1298AC heterozygotes as well as in 677TT/1298AA homozygotes more frequently toxicity incidents were noted. The obtained results suggest that occurrence of 677T allele and coexistence of 677T and 1298C alleles may be associated with lower MTX clearance and elevated risk of adverse effects during MTX-treatment of pediatric ALL patients.

Association of blood lead levels with methylenetetrahydrofolate reductase polymorphisms among Chinese pregnant women in Wuhan city

BACKGROUND

Pregnancy is an important stimulus of bone lead release. Elevated blood lead levels (BLLs) may cause adverse pregnancy outcomes for mothers and harmful lead effects on fetuses. However, the reports about maternal BLL changes during pregnancy are conflicting to some extent. This article is to explore the variations in BLLs among pregnant women. The relationships of BLLs with methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms, which are associated with bone resorption, were also studied. A total of 973 women, including 234, 249, and 248 women in their first, second, and third trimesters, respectively, and 242 non-pregnant women, were recruited at the Wuhan Women and Children Medical Health Center.

METHODS

BLLs were determined using a graphite furnace atomic absorption spectrometer. Single-nucleotide polymorphisms of MTHFR were identified with the TaqMan probe method.

RESULTS

The geometric mean (geometric standard deviation) of BLLs was 16.2 (1.78) μg/L for all participants. All the studied MTHFR alleles were in Hardy-Weinberg equilibrium. Multiple-linear regression analysis revealed the following results. Among the pregnant women, those that carried MTHFR 677CC (i.e. wild-genotype homozygote) and 1298CC (i.e. mutant-genotype homozygote) exhibited higher BLLs than those that carried 677CT/TT (standardized β = 0.074, P = 0.042) and 1298AC/AA (standardized β = 0.077, P = 0.035) when other covariates (e.g., age, no. of children, education and income, etc.) were adjusted. The BLLs of pregnant women consistently decreased during the pregnancy and these levels positively correlated with BMI (standard β = 0.086-0.096, P<0.05).

CONCLUSIONS

The 1298CC mutant-type homozygote in the MTHFR gene is a risk factor for high BLLs among low-level environmental lead-exposed Chinese pregnant women, whose BLLs consistently decreased during gestation.

Increase in the risk of ST elevation myocardial infarction is associated with homocysteine level

BACKGROUND AND AIMS

The present study aimed to investigate the relationship between coagulation defects and ST elevation myocardial infarction (STEMI) in patients without any known coronary artery risk factors and considered low risk according to the Framingham risk classification.

METHODS

This study included 76 (73.6% male) STEMI patients without any known risk factors for coronary artery disease and 56 healthy controls (67.8% male) with similar characteristics.

RESULTS

Factor V Leiden mutation was noted in two patients and in one control. There were no significant differences in protein C, protein S, or antithrombin 3 values between the patient and control groups (p = 0.405, p = 0.476, and p = 0.221, respectively). None of the participants had antiphospholipid syndrome, factor V deficiency, or factor VII deficiency. Plasma homocysteine level was significantly higher in the patient group (19.0 ± 3.6) μmol/L than in the control group (15.8 ± 4.2) μmol/L (p = 0.008). Homocysteine levels in both groups were higher in males without a statistically significant difference. Vitamin B12 and folate levels, which are directly related to homocysteine metabolism, did not differ significantly between groups. Correlation analysis showed that the homocysteine level was not correlated with lipid parameters, folate, or vitamin B12.

CONCLUSION

Homocysteine level was significantly higher in acute MI in patients without any risk factors and were considered low risk according to the Framingham risk score. The findings support the hypothesis that homocysteine level may be an independent risk factor for coronary artery disease.

Maternal dietary intake of folate, vitamin B12 and MTHFR 677C>T genotype: their impact on newborn's anthropometric parameters

In this study, we evaluated the effects of dietary intake of vitamin B12 and folate during pregnancy and their interactions with maternal polymorphism of MTHFR (677C>T; 1298A>C) on intrauterine development. Anthropometric parameters were obtained from 231 newborns that belong to a prospective birth cohort in Morelos, Mexico. Maternal dietary intake of vitamin B12 and folate was assessed using a semi-quantitative questionnaire administered during the first and third trimesters of the pregnancy. Maternal MTHFR 677C>T and 1298 A>C genotypes were determined by PCR-RFLP. The associations between deficient dietary intake of vitamin B12 (<2.0 μg/d) and folate (<400 μg/d) in the first and third trimesters and maternal polymorphisms of MTHFR on anthropometric parameters at birth were estimated using a multivariate linear regression model. During pregnancy, the deficient dietary intake was roughly 60 % for folate and 19 % for vitamin B12. Allelic frequencies of 677T and 1298C were 59 and 10 %, respectively. After adjusting for confounders, deficiency in maternal dietary intake of vitamin B12 (<2.0 μg/d) was associated with a significant reduction in length (β ~ -2.4; 95 % CI -4.3; -0.6) and length-for-age at birth (β ~ -1.2; 95 % CI -2.3; -0.1) among infants whose mothers were carriers of the 677TT genotype (p for interaction = 0.02). In contrast, no association was observed between deficiency in maternal dietary intake of folate (<400 μg/d) and any anthropometric parameter of newborns. These results suggest that supplementation with vitamin B12 during pregnancy could have a favorable impact on intrauterine fetal development mainly in populations that are genetically susceptible.

MTHFR polymorphisms and serum cobalamin affect plasma homocysteine concentrations differentially in females and males

A total of 523 subjects (297 females and 226 males) from the Canary Islands Nutrition Study (ENCA) were studied in order to examine the effect of the MTHFR 677C>T, 1298A>C and 1793G>A polymorphisms, adjusted for age, serum (S)‑folate and S‑cobalamin levels, on total plasma homocysteine concentrations (tHcy). Genotyping was performed with Pyrosequencing® technology. The MTHFR 677T‑allele was associated with increased tHcy concentrations only in males (P=0.005). The MTHFR 1298C‑allele was found to be associated with higher tHcy levels but similarly, only in males (P=0.025). The MTHFR 1793A‑allele was associated with decreased tHcy concentrations in the younger males (P=0.042). A haplotype‑based approach was marginally superior in explaining the genetic interaction of the MTHFR polymorphisms on tHcy plasma levels (R2 0.352 vs. 0.342 for a simple genotype‑based approach). A nutrigenetic interaction between the MTHFR 677C>T genotype and S‑cobalamin on tHcy levels was demonstrated in both genders. The increase in tHcy was more pronounced with decreasing S‑cobalamin quintiles in 677TT homozygotes (P=0.005 for males and P=0.015 for females) than with decreasing S‑folate quintiles (P for trend not significant). It was concluded that gene‑nutrient interactions may differ depending on the sex and age of the subjects. The transferability of gene‑nutrient interactions from one community to others may therefore be limited not only by different food patterns but also by different ages, genders and genotype distributions.

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism among Gaddi tribe of Indian state of Himachal Pradesh

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism has been suggested to be positively associated with several disorders. Distribution of the mutant T-allele varies in ethnic and geographical populations of the world.

AIM

The aim of the present study was to investigate the distribution of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in a transhumant (Gaddi) tribal population of Himachal Pradesh dwelling at high and middle altitude and exposed to strong ultraviolet radiation.

METHOD AND RESULTS

A total of 486 samples (141 males and 345 females) were randomly enrolled from the individuals aged 25-75 years who were unrelated up to first cousin. Among Gaddis, genotype frequencies of CC, CT and TT were 67.90%, 27.78% and 4.32%, respectively. Among males and females distribution of genotype frequencies also followed a similar trend. The studied population was in Hardy-Weinberg equilibrium (χ(2 )= 2.213, df = 1, p = 0.136). Frequency of mutant T-allele in the Gaddi population was found to be 0.183, which might be due to European ancestry, endogamous nature and selection.

MTHFR polymorphism and risk of periprocedural myocardial infarction after coronary stenting

BACKGROUND AND AIM

Pro-thrombotic status and platelet hyperreactivity still represent an important challenge for periprocedural myocardial infarction (PMI) after coronary stenting. Hyperhomocysteinemia has been suggested to increase the risk of cardiovascular events. The genetic variant of methylenetetrahydrofolate reductase (MTHFR) 677 C > T has been associated to reduced function of the enzyme, thus inducing hyperhomocysteinemia. In our study we investigated whether MTHFR 677 C > T polymorphism is associated with increased risk of periprocedural MI in patients undergoing coronary stenting.

METHODS AND RESULTS

We included 778 patients undergoing PCI. Homocysteinemia and genetic status were assessed at admission for all patients. Myonecrosis biomarkers were dosed at intervals from 6 to 48 h, PMI was defined as CKMB increase by 3 times the ULN or 50% of pre-PCI value, periprocedural myonecrosis for troponin I increase by 3 times the ULN or by 50% of the baseline. As many as 521 patients carried the MTHFR-T allele. No difference was found for main demographical and clinical features nor for biochemistry parameters, but for higher rate of statins treatment (p = 0.03) in T-carriers. Polymorphic patients displayed significantly higher levels of homocysteine (p = 0.005), with additive effect of the mutated T-alleles. Angiographic and procedural features were similar according to genetic status. MTHFR677T was not associated with periprocedural myocardial infarction (adjusted OR = 0.97[0.67-1.4], p = 0.87) or myonecrosis (adjusted OR = 1.03[0.83-1.36], p = 0.82). Same results were found at subgroup analysis in higher-risk subsets of patients.

CONCLUSION

Our study showed that among patients undergoing PCI, MTHFR 677 C > T polymorphism is associated to higher homocysteine levels, but does not influence the risk of periprocedural myocardial infarction.

Association between C-reactive protein and homocysteine with the subcomponents of metabolic syndrome in stable patients with bipolar disorder and schizophrenia

BACKGROUND

Previous studies revealed high prevalence of metabolic syndrome (MetS) in patients with bipolar disorder and schizophrenia. C-Reactive protein (CRP) and homocysteine have also both emerged as independent risk factors for the development of cardiovascular disease (CVD) but are less investigated in psychiatric disorders.

AIMS

The aim of this study was to ascertain which specific subcomponents of MetS are associated with levels of CRP and homocysteine in patients with bipolar disorder and schizophrenia.

METHODS

Our sample consisted of patient group (n = 122) (60 bipolar and 62 schizophrenic patients) treated with second-generation antipsychotics (SGA) and healthy controls (n = 59). MetS was defined according to NCEP ATP-III criteria; the cut-off point for elevated CRP was set up at 5 mg/l and for hyperhomocysteinemia at 15 μmol/l.

RESULTS

In the patient group, homocysteine was correlated with waist circumference, systolic and diastolic blood pressure, triglycerides and blood glucose, while CRP was correlated with waist circumference and diastolic blood pressure. Patients with hyperhomocysteinemia had an 8.442 times higher chance to have met the criteria for MetS while elevated CRP was not a significant predictor of MetS.

CONCLUSIONS

There is a complex association between CRP and homocysteine with specific subcomponents of MetS in patients with bipolar disorder and schizophrenia. Given the high risk of cardiovascular disorders in psychiatric patients, these relationships deserve further investigation. Clinically, it could be useful to include the measurement of homocysteine and CRP levels in routine psychiatric diagnostic procedures.

Effect of the MTHFR 677C/T polymorphism on homocysteinemia in response to creatine supplementation: a case study

Creatine (Cr) is recommended as a dietary supplement especially for athletes but its therapeutic potential is also discussed. It is assumed that human body uses Cr for the formation of phosphocreatine, which is necessary for muscular work as a source of energy. Production of Cr in a body is closely connected to methionine cycle where guanidinoacetate (GAA) is in a final step methylated from S-adenosylmethionine (SAM). Increased availability of SAM for phosphatidylcholine (PC) and sarcosine synthesis can potentially stimulate endogenous production of betaine a thus methylation of homocysteine (HCy) to form methionine. Our subject who was methylenetetrahydrofolate reductase (MTHFR) 677TT homozygote lowered plasma HCy from 33.3 micromol/l to 17.1 micromol/l following one-month Cr supplementation (5 g/day) opposite to 677CC and CT genotypes whose HCy levels tended to increase (but still in normal ranges). We suppose that Cr supplementation stimulates pathways leading to production of sarcosine which can serve to regenerate tetrahydrofolate (THF) to form 5,10-methylene-THF. This could potentially increase MTHFR enzyme activity which may later result in increased HCy methylation. Cr supplementation significantly effects metabolism of one carbon unit and potentially lower body´s demands for methyl groups. This could be beneficial as in the case of reduced enzyme activity such as MTHFR 677C/T polymorphism.

Mendelian randomization analysis of the effect of maternal homocysteine during pregnancy, as represented by maternal MTHFR C677T genotype, on birth weight

Background

We used Mendelian randomization analysis to investigate the causal relationship between maternal homocysteine level, as represented by maternal methylenetetrahydrofolate reductase (MTHFR) C677T genotype, with the birth weight of offspring.

Methods

We recruited women at 24 to 28 weeks’ gestation who visited Ewha Womans University Hospital for prenatal care during the period from August 2001 to December 2003. A total of 473 newborns with a gestational age of at least 37 weeks were analyzed in this study. We excluded twin births and children of women with a history of gestational diabetes, gestational hypertension, or chronic renal disease. The association of maternal homocysteine concentration with the birth weight of infants was analyzed using 2-stage regression.

Results

MTHFR C677T genotype showed a dose–response association with homocysteine concentration for each additional T allele (P_trend < 0.01). Birth weight decreased from 120 to 130 grams as maternal homocysteine level increased, while controlling for confounding factors; however, the association was of marginal significance (P = 0.06).

Conclusions

Our results suggest an adverse relationship between maternal homocysteine level and birth weight. A reduction in homocysteine levels might positively affect birth outcomes.

Evaluation of plasma homocysteine level according to the C677T and A1298C polymorphism of the enzyme MTHRF in type 2 diabetic adults

OBJECTIVE

To determine plasma homocysteine levels during fasting and after methionine overload, and to correlate homocysteinemia according to methylenetetrahydrofolate reductase (MTHFR) polymorphism in type 2 diabetic adults.

SUBJECTS AND METHODS

The study included 50 type 2 diabetic adults (DM group) and 52 healthy subjects (Control group). Anthropometric data, and information on food intake, serum levels of vitamin B12, folic acid and plasma homocysteine were obtained. The identification of C677T and A1298C polymorphisms was carried out in the MTHFR gene.

RESULTS

There was no significant difference in homocysteinemia between the two groups, and hyperhomocysteinemia during fasting occurred in 40% of the diabetic patients and in 23% of the controls. For the same polymorphism, there was not any significant difference in homocysteine between the groups. In the Control group, homocysteinemia was greater in those subjects with C677T and A1298C polymorphisms. Among diabetic subjects, those with the A1298C polymorphism had lower levels of homocysteine compared with individuals with C677T polymorphism.

CONCLUSION

The MTHFR polymorphism (C677T and A1298C) resulted in different outcomes regarding homocysteinemia among individuals of each group (diabetic and control). These data suggest that metabolic factors inherent to diabetes influence homocysteine metabolism.

Homocysteine and cognition in first-episode psychosis patients

In the last years, there has been growing evidence linking elevated homocysteine levels with cognitive dysfunction in several neurological and neuropsychiatric diseases. The aim of the present study was to investigate the potential relationship between elevated homocysteine levels and cognitive deficits in first-episode psychosis patients. Plasma levels and cognitive performance of 139 patients and 99 healthy volunteers were compared. Patients were classified as elevated homocysteine (>90 percentile for controls) and normal and compared on 22 cognitive outcome measures grouped into cognitive domains known to be impaired in schizophrenia. Patients had a statistically significant increase in plasmatic homocysteine levels. In addition, they presented with significantly increased cognitive deficits. However, no relationship between homocysteine levels and cognitive impairment was detected. These results suggest the need for further studies to clarify the role of homocysteine in the etiology and prognosis of psychosis.

C677T methylenetetrahydrofolate reductase gene polymorphism as a risk factor involved in venous thromboembolism: a population-based case-control study

The aim of the current study was to investigate the possible correlation between the C677T methylenetetrahydrofolate reductase (MTHFR) polymorphism and venous thromboembolism (VTE) in a population-based case-control study. Homocysteine (Hcy) was quantified by Abbott IMx immunoassay; screening for C677T MTHFR substitution was performed by polymerase chain reaction (PCR) and restriction analysis. The results from the two groups (440 patients and 440 controls) revealed that the frequency of T alleles and TT carriers was significantly higher in patients compared with that of the healthy controls. The plasma levels of Hcy in the VTE group (13.05±2.37 µmol/l) were significantly higher compared with those in the control group (11.94±2.03 µmol/l, P<0.001). The C677T MTHFR polymorphism is suggested to be associated with the risk for VTE. Plasma levels of Hcy were raised in individuals with the homozygous MTHFR 677TT genotype. In conclusion, the results of the current study suggest that hyperhomocysteinemia and the homozygous 677TT MTHFR genotype are risk factors for VTE.

Methylenetetrahydrofolate reductase C677T polymorphism and the risk of male infertility: a meta-analysis

Several molecular epidemiological studies have been conducted to examine the association between MTHFR C677T polymorphism and male infertility susceptibility, but the results remain inconsistent. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 10 case-control studies, including 2275 cases and 1958 controls, were selected. Crude odds ratios (ORs) with 95% confidence intervals were used to assess the strength of association in the additive model, dominant model and recessive model. In the overall analysis, no significant association between the polymorphism and risk of male infertility was observed. Stratified analysis showed that significantly strong association between MTHFR C677T polymorphism and male infertility were present only in Asians (OR = 1.79 for TT vs. CC genotype; OR = 1.42 for CT/TT vs. CC genotype; OR = 1.50 for TT vs. CC/CT genotype; OR = 1.36 for T vs. C allele), but not in Caucasians. Additionally, MTHFR 677T was associated with a significant increase in the risk of azoospermia in all genetic models. No significantly increased risks of oligoasthenoteratozoospermia were found in any of the genetic models. In conclusion, this meta-analysis supports that MTHFR C677T polymorphism is capable of causing male infertility susceptibility in Asians, but not in Caucasians.

Metabolic syndrome and serum homocysteine in patients with bipolar disorder and schizophrenia treated with second generation antipsychotics

There is accumulating evidence for an increased prevalence of metabolic syndrome (MetS) in bipolar patients, which is comparable to the prevalence of MetS in patients with schizophrenia. Hyperhomocysteinaemia has emerged as an independent and graded risk factor for the development of cardiovascular disease (CVD), which is, at the same time, the primary clinical outcome of MetS. The aim of this study was to ascertain if the presence of MetS was associated with hyperhomocysteinaemia in patients with bipolar disorder (N=36) and schizophrenia (N=46) treated with second-generation antipsychotics (SGA). MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP-III) criteria and the cut-off point for hyperhomocysteinaemia was set up at 15 μmoll(-1). Results of the study indicated that the presence of the MetS is statistically significantly associated with the elevated serum homocysteine in all participants. As hyperhomocysteinaemia has emerged as an independent risk factor for psychiatric disorder and CVD, it could be useful to include fasting homocysteine serum determination in the diagnostic panels of psychiatric patients to obtain a better assessment of their metabolic risk profile.

Creatine kinase MM TaqI and methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms influence exercise-induced C-reactive protein levels

Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. Results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.

Genetic polymorphisms influence runners' responses to the dietary ingestion of antioxidant supplementation based on pequi oil (Caryocar brasiliense Camb.): a before-after study

Genes have been implicated in the levels of oxidative stress, lipids, CVD risk, immune reactivity, and performance. Pequi oil (Caryocar brasiliense) has shown anti-inflammatory and hypotensive effects, besides reducing exercise-induced DNA, tissue damages, and anisocytosis. Given that diet can interact with the human genome to influence health and disease, and because genetic variability can influence response to diet, we aim to investigate the influence of 12 gene polymorphisms on inflammatory markers, postprandial lipids, arterial pressure, and plasma lipid peroxidation of runners (N = 125), before and after 14 days of 400 mg pequi-oil supplementation, after races under closely comparable conditions. Arterial pressure was checked before races; blood samples were taken immediately after racing to perform leukogram and plateletgram, Tbars assay, lipid, and CRP dosages and genotyping. CAT, GST-M1/T1, CRP-G1059C, and MTHFR-C677T polymorphisms influenced post-pequi-oil responses in leukogram; Hp and MTHFR-C677T, in plateletgram; Hp, ACE, GSTT1, and MTHFR-A1298C, in lipid profile; MTHFR-A1298C, in C-reactive protein (CRP) levels; and Hp and MnSOD, in Tbars assay. Differences between ACE genotypes in leukogram and total cholesterol disappeared after pequi, and the same occurred for Hp and MnSOD in Tbars assay and for MTHFR-A1298C with CRP levels. Because genetic inheritance is one of the factors that drive atherosclerosis-related lipid abnormalities, results can contribute to a greater understanding of the influence of genetic polymorphisms in situations that push up free radicals. Knowledge is also expanded on how antioxidant supplementation affects an individual's genes and how athletic genetic makeup can affect the way a person responds to antioxidant supplements.

Association of methylenetetrahydrofolate reductase C677T polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

Background

The association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and serum lipid profiles is still controversial in diverse ethnics. Bai Ku Yao is an isolated subgroup of the Yao minority in China. The aim of the present study was to eveluate the association of MTHFR C677T polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.

Methods

A total of 780 subjects of Bai Ku Yao and 686 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the MTHFR C677T was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

Results

The levels of serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.05-0.001). The frequency of C and T alleles was 77.4% and 22.6% in Bai Ku Yao, and 60.9% and 39.1% in Han (P < 0.001); respectively. The frequency of CC, CT and TT genotypes was 58.7%, 37.3% and 4.0% in Bai Ku Yao, and 32.6%, 56.4% and 11.0% in Han (P < 0.001); respectively. The levels of TC and LDL-C in both ethnic groups were significant differences among the three genotypes (P < 0.05-0.01). The T allele carriers had higher serum TC and LDL-C levels than the T allele noncarriers. The levels of ApoB in Han were significant differences among the three genotypes (P < 0.05). The T allele carriers had higher serum ApoB levels as compared with the T allele noncarriers. The levels of TC, TG and LDL-C in Bai Ku Yao were correlated with genotypes (P < 0.05-0.001), whereas the levels of LDL-C in Han were associated with genotypes (P < 0.001). Serum lipid parameters were also correlated with sex, age, body mass index, alcohol consumption, cigarette smoking, and blood pressure in the both ethnic groups.

Conclusions

The differences in serum TC, TG, LDL-C and ApoB levels between the two ethnic groups might partly result from different genotypic and allelic frequencies of the MTHFR C677T or different MTHFR gene-enviromental interactions.

Methylenetetrahydrofolate Reductase gene polymorphism in patients receiving hemodialysis

Methylenetetrahydrofolate Reductase (MTHFR) is key enzyme in metabolism of homocysteine. Homozygotes for mutation (TT genotype) have hyperhomocysteinemia, risk factor for atherosclerosis development. The aim of the study was to find out distribution of genotype frequencies of C677T MTHFR among patients on maintenance hemodialysis. Possible association of alleles and genotypes of C677T polymorphism of the MTHFR gene with age of onset, duration of dialysis and cause of kidney failure was studied also. Cross-sectional study includes 80 patients from Clinic of Hemodialysis KUCS in Sarajevo. In order to perform genotyping, isolated DNA was analyzed by RFLP-PCR and gel-electrophoresis. From total of 80 patients, 42.5% (n=24) were female, 57.5% (n=46) were male, mean age 54.59+/-1.78 years and duration of dialysis 79.92+/-6.32 months. Genotype distribution was: CC 51.2% (n=41), CT 37.5% (n=30) and TT 11.2% (n=9). Patients with wild-type genotype have longer duration of dialysis in month (87.1 +/- 63.93) comparing to TT genotype patients (67.06 +/- 39.3), with no statistical significance. T allele frequency was significantly higher in group of vascular and congenital cause of kidney failure (Pearson X2 =6.049, P<0.05) comparing to inflammation etiology group. Genotype distribution results are within the results other studies in Europe. Obtained results indicate that C677T polymorphism is not associated with onset, duration and cause of kidney failure in our hemodialysis population. There is an association of T allele of the MTHFR gene and vascular and congenital cause kidney failure.

Portal vein thrombosis in Egyptian patients with liver cirrhosis: Role of methylenetetrahydrofolate reductase C677T gene mutation

AIM

The pathogenesis of non-malignant portal vein thrombosis (PVT) in cirrhotic patients is not clearly defined. This case-control study aimed to investigate the role of methylenetetrahydrofolate reductase (MTHFR) C677T gene mutation in the pathogenesis of PVT in Egyptian cirrhotic patients.

METHODS

Plasma homocysteine was measured and MTHFR C677T gene mutation was detected in 76 cirrhotic patients (21 with PVT, 55 without PVT) and 20 healthy controls.

RESULTS

The frequency of CC genotype (wide type) in cirrhotic patients with PVT was lower than controls and cirrhotics without PVT. However, the frequency of TT genotype (homozygous mutation) was elevated in cirrhotic patients with PVT as compared to controls and those without PVT. Cirrhotic patients with PVT had significantly higher homocysteine than those without PVT. Cirrhotic patients with TT genotype are at a significant risk for PVT (odds ratio = 7.7, 95% confidence interval, 1.50-42.81) when compared with CC genotype. Moreover, subjects carrying TT genotype had a higher homocysteine than those carrying CC genotype.

CONCLUSIONS

The TT genotype of MTHFR is associated with an increased risk of PVT in Egyptian cirrhotic patients. Hyperhomocysteinemia could be considered as a relatively new risk factor for PVT in cirrhotic patients and plasma homocysteine should be investigated particularly in patients with PVT of unexplained etiology. The important clinical implication is that the readily available therapy of folate, vitamin B6 and B12 supplementation may reduce homocysteine and prevent further thrombotic complications in cirrhotic patients carrying the TT genotype.

Gene polymorphisms in association with emerging cardiovascular risk markers in adult women

Background

Evidence on the associations of emerging cardiovascular disease risk factors/markers with genes may help identify intermediate pathways of disease susceptibility in the general population. This population-based study is aimed to determine the presence of associations between a wide array of genetic variants and emerging cardiovascular risk markers among adult US women.

Methods

The current analysis was performed among the National Health and Nutrition Examination Survey (NHANES) III phase 2 samples of adult women aged 17 years and older (sample size n = 3409). Fourteen candidate genes within ADRB2, ADRB3, CAT, CRP, F2, F5, FGB, ITGB3, MTHFR, NOS3, PON1, PPARG, TLR4, and TNF were examined for associations with emerging cardiovascular risk markers such as serum C-reactive protein, homocysteine, uric acid, and plasma fibrinogen. Linear regression models were performed using SAS-callable SUDAAN 9.0. The covariates included age, race/ethnicity, education, menopausal status, female hormone use, aspirin use, and lifestyle factors.

Results

In covariate-adjusted models, serum C-reactive protein concentrations were significantly (P value controlling for false-discovery rate ≤ 0.05) associated with polymorphisms in CRP (rs3093058, rs1205), MTHFR (rs1801131), and ADRB3 (rs4994). Serum homocysteine levels were significantly associated with MTHFR (rs1801133).

Conclusion

The significant associations between certain gene variants with concentration variations in serum C-reactive protein and homocysteine among adult women need to be confirmed in further genetic association studies.