Geographical distribution of MTHFR C677T, A1298C and MTRR A66G gene polymorphisms in China: findings from 15357 adults of Han nationality

Geographical distribution of MTHFR C677T gene polymorphisms among the reproductive-age women in Chinese Han populations: based on migration

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) is essential for the metabolism of folic acid and homocysteine. The MTHFR C677T polymorphism is associated with several disorders. Our study aims to explore the geographical distributions of the MTHFR C677T polymorphism of women in China and how migration affected the polymorphism in Suzhou.

METHODS

A total of 7188 women of reproductive age were recruited in Suzhou of the study. Subjects were classified according to their native places after data extraction. MTHFR C677T gene polymorphisms were detected by quantitative PCR with genomic DNA isolated from blood samples.

RESULTS

The frequencies of the 677T allele and 677TT genotype were higher in northern China than that in southern China and decreased in geographical gradients from north to south. The frequencies were considerably higher in the migrant population than that in the indigenous population of Suzhou. The migrant population have gradually changed the prevalence in Suzhou.

CONCLUSIONS

Our study suggested that the prevalence of MTHFR C677T polymorphisms among women varied across different geographical regions in Chinese Han populations. The 677T allele frequencies of the northern populations were significantly higher than those of the southern populations. The migrant population gradually changed the prevalence of the MTHFR C677T polymorphism in Suzhou.

Association of Methylenetetrahydrofolate Reductase rs1801133 Gene Polymorphism with Cancer Risk and Septin 9 Methylation in Patients with Colorectal Cancer

PURPOSE

Colorectal cancer (CRC) is one of the most common malignancies, with a high incidence and mortality worldwide. Methylated Septin 9 (mSEPT9) has been used clinically as an auxiliary tool for CRC screening. The aim of the present study was to investigate the association of the methylenetetrahydrofolate reductase (MTHFR) rs1801133 polymorphism with the risk of CRC and the methylation status of Septin 9 in CRC.

METHODS

Information of 540 patients with a confirmed diagnosis of CRC and with a physical examination were utilized to assess the association of the MTHFR rs1801133 polymorphism with CRC and the methylation of SEPT9. MTHFR rs1801133 polymorphism was genotyped using polymerase chain reaction (PCR). The commercial Septin 9 Gene Methylation(mSEPT9) Detection Kit was used for plasma SEPT9 methylation analysis.

RESULTS

Among 540 patients, 61.48% were men and the median age was 54.47 ± 13.14. 65.37% of all colorectal tumors developed in the rectum. 195 patients had negative mSEPT9 methylation, while 345 had positive results. 87 individuals with stage I, 90 with stage II, 287 with stage III, and 76 with stage IV colorectal cancer were included in the sample. The results demonstrated that the positivity rate and degree of methylation of mSEPT9 were remarkably higher in patients with more advanced TNM stages than in those with less advanced stages. The frequencies of the MTHFR rs1801133 CC genotype and allele C carriers in patients with CRC were significantly higher than those in healthy individuals (P = 0.006 and P = 0.001, respectively). The positivity rate of the mSEPT9 assay was significantly higher among the MTHFR rs1801133 TT genotype and allele T carriers than among the CC and allele C carriers respectively. The MTHFR rs1801133 TT genotype and allele T carriers were positively associated with the methylation of SEPT9 (OR = 3.320, 95% CI 1.485-7.424, P = 0.003 and OR = 1.783, 95% CI 1.056-3.010, P = 0.030, respectively).

CONCLUSION

In conclusion, individuals harboring the MTHFR rs1801133 CC genotype had a higher risk of CRC and the MTHFR rs1801133 TT carriers were more susceptible to Septin 9 gene methylation.

Impact of Thrombophilic Polymorphisms in Antenatal Women on Perinatal Health: A Single-Center Prospective Study

BACKGROUND

Despite pregnancy's hypercoagulable state, the correlation between inherited thrombophilia and thrombotic adverse pregnancy outcomes remains uncertain. The objective of this study was to determine the prevalence of inherited thrombophilic polymorphisms among asymptomatic pregnant individuals and to examine their potential correlation with adverse perinatal outcomes.

METHODS

in this single-center prospective study, 105 healthy pregnant women were included. Genotyping was conducted for factor V Leiden (FVL), prothrombin gene mutation, methylenetetrahydrofolate reductase enzyme (MTHFR) C677T, MTHFR A1298C, and plasminogen activator inhibitor-1 (PAI-1), alongside the assessment of protein C (PC), protein S (PS), and antithrombin (AT) levels. The study analyzed the association between inherited thrombophilic polymorphisms and pregnancy complications linked to placental insufficiency, such as gestational hypertension (GH), preeclampsia (PE), intrauterine death (IUD), fetal growth restriction (FGR), and placental abruption.

RESULTS

The prevalence of identifiable thrombophilic polymorphism mutations was 61.9% (95% confidence interval-CI 52.4-70.8%), with the most common single mutation being PAI-1 4G/5G (12/105, 11.4%, 95% CI 6.4-18.5). The most frequent combined mutation was heterozygosity for MTHFR C677T and PAI-1 (12/105, 11.4%, 95% CI 6.4-18.5). Notably, no FVL homozygous carriers or single homozygous and heterozygous carriers for prothrombin polymorphisms were found. Additionally, no deficiencies in PC and AT were detected among participants. Except for homozygosity for PAI-1, none of the studied polymorphisms demonstrated a significant association with pregnancy complications linked to placental insufficiency.

CONCLUSIONS

The asymptomatic carriers of inherited thrombophilic polymorphisms do not have an increased risk of adverse perinatal outcomes.

Gene variants polymorphisms and uterine leiomyoma: an updated review

Uterine leiomyoma, commonly referred to as fibroids, is a benign tumor that develops in the muscular wall of the uterus. These growths are non-cancerous and can vary in size, ranging from tiny nodules to larger masses. Uterine leiomyomas often occur during a woman's reproductive years and can lead to symptoms such as heavy menstrual bleeding, pelvic pain, and pressure on nearby organs. While the exact cause is not fully understood, hormonal factors, particularly estrogen and progesterone, are believed to play a role in their development. The exploration of connections between genetic variants and uterine leiomyoma has captivated scientific attention for numerous years. The results from investigations remain a subject of intrigue within the scientific community. To date, the findings regarding the relationships between single nucleotide polymorphisms (SNPs) and uterine leiomyoma have exhibited some inconsistencies. However, amidst these inconsistencies, several promising outcomes have emerged that hold the potential to shape future research endeavors. These promising leads could pave the way for the development of innovative targeted therapies and novel prognostic biomarkers. This review specifically centers on accentuating the existing literature data concerning genetic variants that have been explored for their potential connections to uterine leiomyoma. Additionally, it underscores the prospects of employing genetic variations as diagnostic and prognostic biomarkers for individuals diagnosed with uterine leiomyoma.

Global DNA Methylation Levels Viz-a-Viz Genetic and Biochemical Variations in One Carbon Metabolic Pathway: An Exploratory Study from North India

Despite the importance of one carbon metabolic pathway (OCMP) in modulating the DNA methylation process, only a few population-based studies have explored their relationship among healthy individuals. This study aimed to understand the variations in global DNA methylation levels with respect to selected genetic (CBS 844ins68, MTRR A66G, MTR A2756G, and MTHFR C677T polymorphisms) and biochemical (folate, vitamin B12, and homocysteine) markers associated with OCMP among healthy North Indian adults. The study has been conducted among 1095 individuals of either sex (69.5% females), aged 30-75 years. A sample of 5 mL of blood was collected from each participant. Homocysteine, folate, and vitamin B12 levels were determined using the chemiluminescence technique. Restriction digestion was performed for genotyping MTRR A66G, MTR A2756G, and MTHFR C677T polymorphisms and allele-specific PCR amplification for CBS 844ins68 polymorphism. Global DNA methylation levels were analyzed using ELISA-based colorimetric technique. Of the selected genetic and biochemical markers, the mutant MTRR A66G allele was positively associated with global DNA methylation levels. Further, advanced age was inversely associated with methylation levels. MTRR 66GG genotype group was hypermethylated than other genotypes in folate replete and vitamin B12 deficient group (a condition prevalent among vegetarians), suggesting that the G allele may be more efficient than the wild-type allele in such conditions. Global DNA methylation levels appeared to be more influenced by genetic than biochemical factors. MTRR 66G allele may have a selective advantage in vitamin B12 deficient conditions. Further research should be undertaken to understand how genetics affects epigenetic processes.

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

BACKGROUND

Chronic hepatitis B virus (HBV) infection is a severe disease affecting the physical and economic well-being of patients. The relationship between polymorphisms in the MTHFR gene and disease progression following HBV infection remains a controversial topic.

AIM

To study MTHFR and MTRR gene polymorphisms in patients with chronic HBV infections in Zigong, Sichuan Province.

SUBJECTS AND METHODS

One hundred and ninety-one patients with chronic HBV infections were divided into three groups: the chronic hepatitis B (CHB) group (n = 71), the hepatitis B-induced liver cirrhosis (LC) group (n = 56), and the hepatitis B-related primary liver cancer (PLC) group (n = 64). The gene polymorphisms were detected using the PCR-melt curve method and analysed.

RESULTS

The distributions of MTHFR C677T (CC: 41.2% vs. 41.8%; CT: 50% vs. 45.5%; TT: 8.8% vs. 12.7%; p = 0.714), MTHFR A1298C (AA: 70.6% vs. 72.7%; AC: 26.5% vs. 25.5%; CC: 2.9% vs. 1.8%; p = 1.000), and MTRR A66G (AA: 58.1% vs. 65.5%; AG: 39.0% vs. 29.1%; 2.9% vs. 5.5%; p = 0.353) genetic polymorphisms did not vary between male and female patients from Zigong. In addition, there were no differences in the distributions of MTHFR C677T (CC: 43.4% vs. 38.8%; CT: 49.1% vs. 48.2%; TT: 7.5% vs. 12.9%; p = 0.444), MTHFR A1298C (AA: 76.4% vs. 64.7%; AC: 20.8% vs. 32.9%; CC: 2.8% vs. 2.4%; p = 0.155), and MTRR A66G (AA: 62.3% vs. 57.6%; AG: 34.0% vs. 38.8%; 3.8% vs. 3.5%; p = 0.353) genetic polymorphisms between the patients <60 and >60 years of age. The distributions of MTHFR C677T (CHB vs. LC, p = 0.888; CHB vs. PLC, p = 0.661; PLC vs. LC, p = 0.926), MTHFR A1298C (CHB vs. LC, p = 0.12; CHB vs. PLC, p = 0.263; PLC vs. LC, p = 0.550), and MTRR A66G (CHB vs. LC, p = 0.955; CHB vs. PLC, p = 0.645; PLC vs. LC, p = 0.355) gene polymorphisms were comparable between the CHB, LC, and PLC groups.

CONCLUSION

The distributions of MTHFR and MRRR genetic polymorphisms in the population with HBV infections in Zigong, Sichuan Province did not differ in age and sex. The MTHFR and MRRR genetic polymorphisms were comparable between the CHB, LC, and PLC groups.

Association of maternal methionine synthase reductase gene polymorphisms with the risk of congenital heart disease in offspring: a hospital-based case-control study

BACKGROUND

Evidence suggests that periconceptional folic acid supplementation may prevent congenital heart disease (CHD). Methionine synthase reductase (MTRR) is one of the key regulatory enzymes in the folate metabolic pathway. This study aimed to comprehensively evaluate the association of single nucleotide polymorphisms (SNPs) in the maternal MTRR gene with CHD risk in offspring.

METHODS

A hospital-based case-control study involving 740 mothers of CHD cases and 683 health controls was conducted.

RESULTS

The study showed that maternal MTRR gene polymorphisms at rs1532268 (C/T vs. C/C: aOR = 1.524; T/T vs. C/C: aOR = 3.178), rs1802059 (G/A vs. G/G: aOR = 1.410; A/A vs. G/G: aOR = 3.953), rs2287779 (G/A vs. G/G: aOR = 0.540), rs16879334 (C/G vs. C/C: aOR = 0.454), and rs2303080 (T/A vs. T/T: aOR = 0.546) were associated with the risk of CHD. And seven haplotypes were observed to be associated with the risk of CHD, T-G-A haplotype (OR = 1.298), C-A-C-C (OR = 4.824) and A-G haplotype (OR = 1.751) were associated with increased risk of CHD in offspring; A-A-A (OR = 0.773), T-A-A (OR = 0.557), G-A-C-C (OR = 0.598) and G-C (OR = 0.740) were associated with decreased risk of CHD in offspring.

CONCLUSIONS

Maternal MTRR gene polymorphisms were associated with CHD in offspring, and its haplotypes have affected the occurrence of CHD. Furthermore, given the complexity and heterogeneity of CHD, the mechanisms by which these factors influence offspring cardiac development remain unknown, and studies in larger samples in an ethnically diverse population are needed.

MTHFR A1298C polymorphism: a predictor of reduced risk of preeclampsia in Punjab, Pakistan

OBJECTIVES

This study aimed to investigate the genetic association between MTHFR (A1298C) SNP and preeclampsia (PE) in Punjab, Pakistan.

METHODS

A sample of 80 pregnant women (40 healthy pregnant women and 40 with PE) was pooled for genotyping MTHFR A1298C polymorphism by using the tetra-primer amplification refractory mutation system (ARMS) PCR. The Genotypic and allelic assessments were performed using various statistical techniques.

RESULTS

The AC genotype and C allele of MTHFR A1298C were found to be associated with decreased risk of PE (odds ratio [OR]: 0.31, risk ratio [RR]: 0.58, p = 0.01), and (odds ratio [OR]: 0.49, risk ratio [RR]: 0.61, p = 0.04), respectively.

CONCLUSION

In conclusion, genetic polymorphism A1298C in MTHFR may pose a protective effect in the studied population.

Serum folate mediates the associations of MTHFR rs1801133 polymorphism with blood glucose levels and gestational diabetes mellitus in Chinese Han pregnant women

This study aimed to explore the mediation effects of one-carbon metabolism (OCM) related nutrients on the association between MTHFR rs1801133 polymorphism and gestational diabetes mellitus (GDM). Folate, vitamin B12 and homocysteine (Hcy) were measured in the serum of 1254 pregnant women. Linear and logistic regressions were used to estimate the associations of OCM nutrients and MTHFR rs1801133 polymorphism with blood glucose levels and GDM risk. Mediation analysis was applied to test the mediation effects of folate, vitamin B12 and Hcy on the association of MTHFR rs1801133 polymorphism with blood glucose concentrations and GDM. Pregnant women with MTHFR rs1801133 CC genotype had higher serum folate (10·75 v. 8·90 and 9·40 ng/ml) and lower serum Hcy (4·84 v. 4·93 and 5·20 μmol/l) than those with CT and TT genotypes. Folate concentrations were positively associated with fasting plasma glucose (FPG), 1-h plasma glucose (1-h PG), 2-h plasma glucose (2-h PG) and GDM risk. Vitamin B12 levels were negatively correlated with FPG and GDM. Although no direct association was found between MTHFR rs1801133 genotypes and GDM, there were significant indirect effects of MTHFR rs1801133 CC genotype on FPG (β: 0·005; 95 % CI: 0·001, 0·013), 1-h PG (β: 0·006; 95 % CI: 0·001, 0·014), 2-h PG (β: 0·007; 95 % CI: 0·001, 0·015) and GDM (β: 0·006; 95 % CI: 0·001, 0·014) via folate. In conclusion, serum folate mediates the effect of MTHFR rs1801133 on blood glucose levels and GDM. Our findings potentially provide a feasible GDM prevention strategy via individualised folate supplementation according to the MTHFR genotypes.

RART-LAMP: One-Step Extraction-Free Method for Genotyping within 40 min

Loop-mediated isothermal amplification (LAMP) is a commonly used alternative to PCR for point-of-care detection of nucleic acids due to its rapidity, sensitivity, specificity, and simpler instrumentation. While dual-labeled TaqMan probes are widely used in PCR for single-nucleotide polymorphism (SNP) genotyping, real-time LAMP primarily relies on turbidimetry or intercalator fluorescence measurements, which can be non-specific and generate false-positive results. In this study, we propose a closed-tube, dual-labeled RNA-modified probes and RNase H II-assisted real-time LAMP (RART-LAMP) method for SNP genotyping. Our findings indicate that (1) fluorescence signals were predominantly derived from probe hydrolysis rather than hybridization, (2) temperature-controlled hybridization between the probe and template ensured the specificity of SNP analysis, and (3) RNase H II hydrolysis between the target containing SNP sites and probes did not exhibit sequence specificity. Our RART-LAMP approach demonstrated excellent performance in genotyping C677T clinical samples, including gDNA extracted from blood, saliva, and swabs. More importantly, saliva and swab samples could be directly analyzed without any pretreatment, indicating promising prospects for nucleic acid analysis at the point of care in resource-limited settings.

MTHFR act as a potential cancer biomarker in immune checkpoints blockades, heterogeneity, tumor microenvironment and immune infiltration

PURPOSE

To evaluate the role and landscape of 5-10-Methylenetetrahydrofolate reductase (MTHFR) to immune infiltration, tumor microenvironment, heterogeneity, immune checkpoints blockades, prognostic significance across cancer types.

METHODS

Data sets of genomic, transcriptomic and clinic features of MTHFR across > 60,000 patients and up to 44 cancer types were comprehensively analyzed using R software.

RESULTS

Expression of MTHFR gene is significantly lower in 17 tumors and correlated with overall survival (OS), disease-specific survival (DSS), progression-free interval (PFI) in specific tumors. Gene alterations of MTHFR are observed significant differences across tumor types. Expression of MTHFR is negatively correlated with the stemness index (mDNAsi, mRNAsi, DMPsi, ENHsi, EREG-mDNAsi and EREG-mRNAsi) in the most cancers. MTHFR showed significantly correlated with 67 types of immune cell infiltration scores in 44 cancer types by XCELL algorithm. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis are conducted to show the core tumor mechanism and biological process. Correlations between MTHFR and biomarkers of heterogeneity (MSI, TMB, MATH, HRD, LOH, Neoantigen, ploidy and purity) are also significant in specific tumors. MTHFR is significantly positively correlated with biomarkers of immune related genes (CD19, CD274, CD80, CD86) and mismatched repair genes (MLH1, PMS2, MSH2, MSH6, EPCAM, MLH3, PMS1, EXO1) in most cancer types. Receiver Operating Characteristics (ROC) analyses show MTHFR could act as a potential biomarker in anti-PD-1 (nivolumab to melanoma) and anti-CTLA4 (ipilimumab to melanoma) group of ontreatment, in anti-PD-1 (pembrolizumab to melanoma) group of pretreatment. Two immunohistochemistry antibodies HPA076180 and HPA077255 are verified in 20 types of tumor and could be used to detect the expression of MTHFR efficiently in clinic.

CONCLUSIONS

MTHFR could predict the response of immune checkpoints blockades, heterogeneity, tumor microenvironment and immune infiltration.

Association between Micronutrients and Hyperhomocysteinemia: A Case-Control Study in Northeast China

Hyperhomocysteinemia (HHcy) is an independent risk factor for cardiovascular and cerebrovascular diseases where the plasma homocysteine (Hcy) concentration exceeds 15 µmol/L. HHcy is affected by vitamins B12, B6, and folic acid (fol); however, its relationship with other nutrients is not fully understood. We investigated the nutritional and genetic factors associated with HHcy and the possible dose-response relationships or threshold effects in patients in Northeast China. Genetic polymorphisms and micronutrients were tested with polymerase chain reaction and mass spectrometry, respectively. This trial was registered under trial number ChiCTR1900025136. The HHcy group had significantly more males and higher body mass index (BMI), methylenetetrahydrofolate reductase (MTHFR 677TT) polymorphism proportion, and uric acid, Zn, Fe, P, and vitamin A levels than the control group. After adjusting for age, sex, BMI, vitamin B12, fol, and MTHFR C677T, the lowest Zn quartile reduced the odds ratio of HHcy compared with the highest Zn quartile. The dose-response curves for the association between plasma Zn and HHcy were S-shaped. High plasma Zn concentrations were significantly correlated with high HHcy odds ratios, and the curve leveled off or slightly decreased. Most importantly, HHcy risk decreased with decreasing plasma Zn concentration; the threshold was 83.89 µmol/L. Conclusively, individuals residing in Northeast China, especially those with the MTHFR 677TT polymorphism, must pay attention to their plasma Zn and Hcy levels.

Associations of MTHFR gene polymorphism with lipid metabolism and risk of cerebral infarction in the Northwest Han Chinese population

Objective

Genetic variation in the methylenetetrahydrofolate reductase (MTHFR) gene may contribute to the development of cerebral infarction (CI); however, results have been inconsistent across studies with different populations, including studies of the Chinese population. The aim of this study was to analyze the effect of MTHFR gene polymorphism on serum lipid and homocysteine levels among patients with CI in the Northwest Chinese Han population.

Patients and methods

A total of 521 CI patients and 524 non-CI controls were enrolled in the study. Polymerase chain reaction and hybridization were utilized to identify MTHFR gene polymorphisms. Multivariate logistic regression analysis was used to assess the associations of MTHFR gene polymorphism with risk of CI.

Results

Frequencies of the TT genotype and the T allele were markedly higher among CI patients than among controls. After stratifying our data by sex and age, we determined that these differences in frequency of the TT genotype and the T allele were statistically significant among participants of two different age brackets and among men, but not among women (i.e., there were no statistically significant differences between female patients and female controls). CI patients and control participants with the CT or TT genotype had significantly higher homocysteine (Hcy) levels than those with the CC genotype. Among CI patients, CT/TT carriers showed significantly lower high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (ApoA-I) levels as compared with CC carriers, but there was no significant difference for control participants. Multivariable logistic regression analysis showed that drinking; smoking; diabetes mellitus; levels of Hcy, direct bilirubin (DB), indirect bilirubin (IB), ApoA-I, and total protein (TP); and TT genotype were significant independent risk factors for CI.

Conclusions

The results suggested that the TT genotype of the MTHFR C677T gene polymorphism, which is associated with hyperhomocysteinemia (HHcy), might be of great clinical significance in the identification of new biomarkers for CI and in the development of individualized preventive and therapeutic strategies.

Effects of low-dose B vitamins plus betaine supplementation on lowering homocysteine concentrations among Chinese adults with hyperhomocysteinemia: a randomized, double-blind, controlled preliminary clinical trial

PURPOSE

To test the hypothesis that daily supplementation with low-dose B vitamins plus betaine could significantly reduce plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia and free from background mandatory folic acid fortification.

METHODS

One hundred apparently healthy adults aged 18-65 years with hyperhomocysteinemia were recruited in South China from July 2019 to June 2021. They were randomly assigned to either the supplement group (daily supplementation: 400 μg folic acid, 8 mg vitamin B₆, 6.4 μg vitamin B₁₂ and 1 g betaine) or the placebo group for 12 weeks. Fasting venous blood was collected at baseline, week 4 and week 12 to determine the concentrations of homocysteine, folate, vitamin B₁₂ and betaine. Generalized estimation equations were used for statistical analysis.

RESULTS

Statistically significant increments in blood concentrations of folate, vitamin B₁₂ and betaine after the intervention in the supplement group indicated good participant compliance. At baseline, there were no significant differences in plasma homocysteine concentration between the two groups (P = 0.265). After 12-week supplementation, compared with the placebo group, there was a significant reduction in plasma homocysteine concentrations in the supplement group (mean group difference - 3.87; covariate-adjusted P = 0.012; reduction rate 10.1%; covariate-adjusted P < 0.001). In the supplement group, the decreased concentration of plasma homocysteine was associated with increments of blood concentrations of both folate (β = -1.680, P = 0.004) and betaine (β = -1.421, P = 0.020) after 12 weeks of supplementation.

CONCLUSIONS

Daily supplementation with low-dose B vitamins plus betaine for 12 weeks effectively decreased plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia.

TRIAL REGISTRATION

This trial was registered at clinicaltrials.gov as NCT03720249 on October 25, 2018. Website: https://clinicaltrials.gov/ct2/show/NCT03720249 .

Regional distribution of the MTHFR C677T polymorphism in Chinese females

Objective: For analyzing the distribution characteristics of MTHFR C677T polymorphism in Chinese females in order to provide information for reducing birth defects and formulating public health policies to prevent congenital malformations. Methods: Literature search in the last 6 years on "MTHFR C677T," "polymorphism" and "methylene tetrahydrofolate reductase." The included literature provides the MTHFR C677T frequency in healthy females in the corresponding regions. The data were grouped by the national administrative region as a unit to obtain the distribution information of the MTHFR C677T and alleles in the female population in every province, municipality or autonomous region. This was done for analyzing the overall distribution of the MTHFR C677T allele and the geographical distribution of pregnancy complications. Results: A total of 126 studies were included, covering five autonomous areas, four municipalities directly under the Central Government, as well as 22 provinces (except Taiwan Province) in China. MTHFR C677T polymorphism data of 27 groups of Chinese Han women and 31 groups of other Chinese females were obtained, and the chi-square test revealed notable inter-group differences (p = 0.000). The TT genotype and T allele of MTHFR C677T accounted for 18.2% (4.7%-38.3%) and 40.3% (19.7%-61.4%) of the Chinese female population, respectively, with a significant north-south difference. Chinese females had a consistent frequency of the T allele with the geographical distribution of pregnancy complications such as recurrent abortion and preeclampsia. Conclusion: With a obvious geographical gradient, the MTHFR C677T polymorphism distribution in Chinese females is consistent with the geographical distribution of multiple pregnancy complications, and the risk assessment for it might be included in primary prevention for birth defects.

Biosynthesis of L-5-methyltetrahydrofolate by genetically engineered Escherichia coli

L-5-Methyltetrahydrofolate (L-5-MTHF) is the only biologically active form of folate in the human body. Production of L-5-MTHF by using microbes is an emerging consideration for green synthesis. However, microbes naturally produce only a small amount of L-5-MTHF. Here, Escherichia coli BL21(DE3) was engineered to increase the production of L-5-MTHF by overexpressing the intrinsic genes of dihydrofolate reductase and methylenetetrahydrofolate (methylene-THF) reductase, introducing the genes encoding formate-THF ligase, formyl-THF cyclohydrolase and methylene-THF dehydrogenase from the one-carbon metabolic pathway of Methylobacterium extorquens or Clostridium autoethanogenum and disrupting the gene of methionine synthase involved in the consumption and synthesis inhibition of the target product. Thus, upon its native pathway, an additional pathway for L-5-MTHF synthesis was developed in E. coli, which was further analysed and confirmed by qRT-PCR, enzyme assays and metabolite determination. After optimizing the conditions of induction time, temperature, cell density and concentration of IPTG and supplementing exogenous substances (folic acid, sodium formate and glucose) to the culture, the highest yield of 527.84 μg g^-1 of dry cell weight for L-5-MTHF was obtained, which was about 11.8 folds of that of the original strain. This study paves the way for further metabolic engineering to improve the biosynthesis of L-5-MTHF in E. coli.

Association of MTHFR 677C>T polymorphism with pregnancy outcomes in IVF/ICSI-ET recipients with adequate synthetic folic acid supplementation

Methylenetetrahydrofolate reductase (MTHFR) genetic polymorphism rs1801133 (677C>T) will decrease the utilization of folate. Folate deficiency and its resulting homocysteine (HCY) accumulation can impair female fertility. Folic acid (FA) supplementation is necessary in pregnant women who are undergoing in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) - embryo transfer (ET), and especially in women with MTHFR rs1801133 C-to-T mutations. At present, affordable and accessible synthetic FA is mainly used. However, some studies have suggested that 5-methylenetetrahydrofolate (5-MTHF), a type of active FA, may be more suitable for women with the MTHFR 677C>T polymorphism, since it is safer and more effective. This retrospective study aimed to evaluate whether the MTHFR rs1801133 gene polymorphism is related to the pregnancy outcomes of IVF/ICSI-ET recipients after sufficient supplementation with FA instead of 5-MTHF. Data on 692 women undergoing IVF/ICSI-ET and taking adequate FA were collected. Participant characteristics were compared using the Kruskal-Wallis test and Pearson chi-square test. Logistic regressions were used to calculate the odds ratio (OR) and 95% confidence interval (95% CI), after adjusting for age, BMI, method of fertilization, method of embryo transfer and number of embryos transferred. An additive model (T/T vs. C/C), dominant model (C/T + T/T vs. C/C), and recessive model (T/T vs. C/T + C/C) were evaluated. Analysis revealed that MTHFR rs1801133 in IVF/ICSI-ET women with adequate FA supplementation was not associated with the pregnancy rate but with age (OR = 0.91, 95% CI = 0.88, 0.94, P < 0.001) and BMI (OR = 0.95, 95% CI = 0.90, 0.997, P = 0.037). In 349 clinically pregnant women, no association of the MTHFR 677C>T with pregnancy outcomes was found in the additive model, dominant model, or recessive model. Of the 273 women with positive pregnancy outcomes, 34 had a preterm delivery. MTHFR 677C>T was not associated with a preterm delivery after adjusting for age and BMI. The current results indicated that MTHFR polymorphism rs1801133 was not related to the pregnancy rate or pregnancy outcomes of women undergoing IVF/ICSI-ET with adequate synthetic FA supplementation, suggesting that simple supplementation with less expensive and readily available FA, rather than expensive 5-MTHF, appeared to be appropriate.

[Association between MTHFR gene polymorphism and primary hypertension in children]

OBJECTIVES

To study the distribution characteristics of methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism in children with primary hypertension, and to explore the association between MTHFR C677T gene polymorphism and H-type hypertension in children.

METHODS

A total of 121 children with primary hypertension who were hospitalized in the department of cardiovascular medicine from January to July 2021, newly diagnosed, and untreated were retrospectively selected as the subjects. The children were divided into three groups: CC genotype (19 children), CT genotype (51 children), and TT genotype (51 children). According to the serum homocysteine (Hcy) level, they were divided two groups: H-type hypertension (47 children) and simple hypertension (74 children). The medical data were compared between the groups. The association between MTHFR C677T gene polymorphism and H-type hypertension was evaluated.

RESULTS

The mutation frequency of T allele in children with primary hypertension was significantly higher than that in healthy adults in Beijing and Chinese Han adults (P<0.001). The serum Hcy level in the TT genotype group was significantly higher than that in the CC and CT genotype groups (P<0.001). The serum Hcy level in the H-type hypertension group was significantly higher than that in the simple hypertension group (P<0.001), and MTHFR C677T was mostly TT genotype, which was associated with the risk of H-type hypertension (OR=12.71, P<0.001). There was no significant difference in the incidence rate of target organ damage between the H-type hypertension and simple hypertension groups (P>0.05). However, multiple organ involvement was observed in the H-type hypertension group at diagnosis, accounting for 11% (5/47).

CONCLUSIONS

The mutation rate of MTHFR C677T T allele in children with primary hypertension is high and associated with the serum Hcy level. TT genotype is an independent risk factor for H-type hypertension in children, and it may be related to the severity of early target organ damage.

Endothelial Dysfunction and Hyperhomocysteinemia-Linked Cerebral Small Vessel Disease: Underlying Mechanisms and Treatment Timing

Cerebral small vessel disease (cSVD)—a common cause of stroke and vascular dementia—is a group of clinical syndromes that affects the brain's small vessels, including arterioles, capillaries, and venules. Its pathogenesis is not fully understood, and effective treatments are limited. Increasing evidence indicates that an elevated total serum homocysteine level is directly and indirectly associated with cSVD, and endothelial dysfunction plays an active role in this association. Hyperhomocysteinemia affects endothelial function through oxidative stress, inflammatory pathways, and epigenetic alterations at an early stage, even before the onset of small vessel injuries and the disease. Therefore, hyperhomocysteinemia is potentially an important therapeutic target for cSVD. However, decreasing the homocysteine level is not sufficiently effective, possibly due to delayed treatment, which underlying reason remains unclear. In this review, we examined endothelial dysfunction to understand the close relationship between hyperhomocysteinemia and cSVD and identify the optimal timing for the therapy.

Exome-Wide Association Study Identifies East Asian-Specific Missense Variant MTHFR C136T Influencing Homocysteine Levels in Chinese Populations RH: ExWAS of tHCY in a Chinese Population

Plasma total homocysteine (tHCY) is a known risk factor of a wide range of complex diseases. No genome scans for tHCY have been conducted in East Asian populations. Here, we conducted an exome-wide association study (ExWAS) for tHCY in 5,175 individuals of Chinese Han origin, followed by a replication study in 668 Chinese individuals. The ExWAS identified two loci, 1p36.22 (lead single-nucleotide polymorphism (SNP) rs1801133, MTHFR C677T) and 16q24.3 (rs1126464, DPEP1), showing exome-wide significant association with tHCY (p < 5E-7); and both loci have been previously associated with tHCY in non-East Asian populations. Both SNPs were replicated in the replication study (p < 0.05). Conditioning on the genotype of C677T and rs1126464, we identified a novel East Asian-specific missense variant rs138189536 (C136T) of MTHFR (p = 6.53E-10), which was also significant in the replication study (p = 9.8E-3). The C136T and C677T variants affect tHCY in a compound heterozygote manner, where compound heterozygote and homozygote genotype carriers had on average 43.4% increased tHCY than had other genotypes. The frequency of the homozygote C677T genotype showed an inverse-U-shaped geospatial pattern globally with a pronounced frequency in northern China, which coincided with the high prevalence of hyperhomocysteinemia (HHCY) in northern China. A logistic regression model of HHCY status considering sex, age, and the genotypes of the three identified variants reached an area under the receiver operating characteristic curve (AUC) value of 0.74 in an independent validation cohort. These genetic observations provide new insights into the presence of multiple causal mutations at the MTHFR locus, highlight the role of genetics in HHCY epidemiology among different populations, and provide candidate loci for future functional studies.

Genetic variations as molecular diagnostic factors for idiopathic male infertility: current knowledge and future perspectives

INTRODUCTION

Infertility is a major health problem, worldwide, which affects 10-15% of couples. About half a percent of infertility cases are related to male-related factors. Male infertility is a complex disease that is the result of various insults as lifestyle issues, genetics, and epigenetic factors. Idiopathic infertility is responsible for 30% of total cases. The genetic factors responsible for male infertility include chromosomal abnormalities, deletions of chromosome Y, and mutations and genetic variations of key genes.

AREAS COVERED

In this review article, we aim to narrate performed studies on polymorphisms of essential genes involved in male infertility including folate metabolizing genes, oxidative stress-related genes, inflammation, and cellular pathways related to spermatogenesis. Moreover, possible pathophysiologic mechanisms responsible for genetic polymorphisms are discussed.

EXPERT OPINION

Analysis and assessment of these genetic variations could help in screening, diagnosis, and treatment of idiopathic male infertility.

Methylenetetrahydrofolate Reductase Gene C677T Polymorphism-Dietary Pattern Interaction on Hyperhomocysteinemia in a Chinese Population: A Cross-Sectional Study

Background and aim: Hyperhomocysteinemia (Hhcy) has been recognized as a risk factor of several chronic diseases. There is accumulating evidence that both genetic and dietary factors had a notable impact on the risk of Hhcy. The present study aims to investigate the interaction effect on Hhcy between methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and dietary intake.

Methods: Data were collected in a cross-sectional survey conducted in China; 3,966 participants with complete information on sociodemographic characteristics, anthropometric measurements, and dietary intake were included in the analyses. Dietary patterns were identified by factor analysis combined with cluster analysis. Blood samples were collected and MTHFR C677T genotypes were tested. Both the multiplicative statistical model and the additive model were conducted to investigate the interactive effects.

Results: Proportions of MTHFR C677T genotypes among participants were 29.2% for TT, 47.4% for CT, and 23.4% for CC. Three dietary patterns were identified, namely, the balanced pattern, the snack pattern, and the high-meat pattern. Compared with the balanced pattern, the other two patterns were associated with an elevated risk of Hhcy [the snack pattern: odds ratio (OR) 1.2, 95% confidence interval (CI) 1.0–1.5; the high-meat pattern: OR 1.3, 95% CI 1.1–1.6] after adjustment for age group, gender, residential region, and MTHFR C677T genotypes. A multiplicative interaction between the high-meat pattern and MTHFR 677TT genotype was observed, and synergistic effects between both the snack pattern and the high-meat pattern with MTHFR 677TT were identified.

Conclusion: Our results indicated that MTHFR C677T polymorphism and dietary patterns had interactive effects on Hhcy among the Chinese population. Subsequent targeted and appropriate dietary guidelines should be recommended for high-risk populations or patients of Hhcy carrying specific genotypes.

The association between 5, 10 - methylenetetrahydrofolate reductase and the risk of unexplained recurrent pregnancy loss in China: A Meta-analysis

BACKGROUD

To analyze the correlation between gene polymorphisms of 5,10- methylenetetrahydrofolate reductase (MTHFR) and risk of unexplained recurrent pregnancy loss (URPL) in Chinese women.

METHODS

Eligible studies were searched in Pubmed, Embase, Web of Science, Wanfang, and China National Knowledge Infrastructure (CNKI) databases. Established inclusion criteria were used to screening articles, subsequently evaluate the quality of the included studies, Stata 16.0 PM and RevMan 5.3 software were conducted for meta-analysis. The pooled odds ratio (OR) with 95% confidence interval (CI) was determined to assess the relationship between MTHFR and risk of URPL in Chinese women.

RESULTS

For MTHFR C677T, fifty studies were included, involving 6677 URPL cases and 8111 controls. The overall results showed that MTHFR C677T was significantly correlated with URPL risk, especially in the homozygous model (TT vs CC; OR 3.06; 95% CI 2.56-3.66). For MTHFR A1298C, twenty-first studies were included, involving 3439 URPL cases and 3155 controls. The results showed that MTHFR A1298C was also significantly correlated with URPL risk in recessive (CC vs AC + AA; OR 1.55; 95% CI 1.25-1.93) and homozygous (CC vs AA; OR 1.53; 95% CI 1.22-1.91) models. In addition, sub-group results showed that no significant difference between north and south China populations in the MTHFR gene polymorphisms and URPL risk. Of note, the patients carrying MTHFR C677T and MTHFR A1298C joint mutants had no synergistic effect (OR 2.71; 95% CI 0.84-8.70) on the occurrence of URPL compared with the wild-type homozygous genotype (MTHFR 677CC/ MTHFR 1298AA).

CONCLUSION

Studies included in this meta-analysis suggested that MTHFR 677T allele and 677TT genotype and MTHFR 1298CC genotype were both associated with URPL; testing MTHFR C677T gene polymorphism was a more appropriate target compared with other mutations in the prediction of URPL.

Methylenetetrahydrofolate reductase gene polymorphisms in the risk of polycystic ovary syndrome and ovarian cancer

Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) in hormone metabolism pathways might cause metabolic disturbances and contribute to the development of polycystic ovary syndrome (PCOS) and ovarian cancer, but the published studies were inconsistent. The aim of the present study was to evaluate the MTHFR C677T (rs1801133) and A1298C (rs1801131) gene polymorphisms in the risk of PCOS and ovarian cancer by meta-analysis. A comprehensive electronic search was conducted in databases for studies published from 1995 to 2020. The pooled ORs were calculated by Revman 5.2 software. Twenty-nine articles including 45 case–control studies were included. We found that MTHFR C677T polymorphisms were correlated with elevated PCOS risk (TT vs. CT+CC: OR = 1.41, 95%CI = 1.20–1.67; TT+CT vs. CC: OR = 1.54, 95%CI = 1.07–2.22; CT vs. CC+TT: OR = 1.18, 95%CI 1.04–1.33; TT vs. CC: OR = 1.47, 95%CI = 1.03–2.11; T vs. C: OR = 1.25, 95%CI = 1.06–1.47), which were more obvious in Middle Eastern subgroup. MTHFR A1298C polymorphisms were also associated with overall PCOS susceptibility (CC vs. AC+AA: OR = 2.55, 95% CI = 1.61–4.03; CC+AC vs. AA: OR = 1.84, 95%CI = 1.04–3.28; CC vs. AA: OR = 2.66, 95%CI = 1.68–4.22; C vs. A: OR = 1.67, 95%CI = 1.03–2.71), which were mainly reflected in Asian subjects. For ovarian cancer, MTHFR C677T polymorphisms were only related with elevated ovarian cancer risk in Asian population, while no significant association was found for A1298C polymorphisms. This meta-analysis suggested that MTHFR C677T and MTHFR A1298C polymorphisms were correlated with elevated PCOS risk. MTHFR C667T only posed a higher risk for ovarian cancer in Asians instead of other populations, while MTHFR A1298C polymorphisms were not related to ovarian cancer risk. Further studies are needed to validate the conclusion.

Genetic effect of MTHFR C677T, A1298C, and A1793G polymorphisms on the age at onset, plasma homocysteine, and white matter lesions in Alzheimer's disease in the Chinese population

Background: Three polymorphisms in the Methylenetetrahydrofolate reductase (MTHFR) gene (C677T, A1298C, and A1793G) were reported associated with AD. However, their genotype distributions and associations with age at onset (AAO), homocysteine, and white matter lesions (WML) were unclear in the Chinese AD population.

Method: We determined the presence of C677T, A1298C, and A1793G polymorphisms in the MTHFR gene using Sanger sequencing in a Chinese cohort comprising 721 AD patients (318 early-onset AD patients (EOAD) and 403 late-onset AD patients (LOAD)) and 365 elderly controls. Additionally, the homocysteine level and WML were evaluated in 121 AD patients.

Results: The frequency of allele T of C677T polymorphism was significantly higher in AD patients than in controls (P = 0.040), while no statistical difference was observed in A1298C and A1793G (P > 0.05). Besides, genotype distributions of C677T and A1298C polymorphisms statistically varied between AD patients and controls (P = 0.021, P = 0.012). Moreover, the AAO was significantly lower in CT/TT (C677T) genotypes carriers (P = 0.042) and higher in AC/CC (A1298C) and AG/GG (A1793G) genotypes carriers (P = 0.034, P = 0.009) in patients with LOAD. We also found that patients with CT/TT (C677T) genotypes were prone to present an increased homocysteine level (P = 0.036) and higher Fazekas score (P = 0.024). In comparison, patients with AG/GG genotypes (A1793G) had a significantly lower Fazekas score (P = 0.013).

Conclusions: The genotype distributions of C677T and A1298C polymorphisms are associated with AD in the Chinese population. Moreover, AD patients with C677T polymorphism are prone to present an earlier onset, higher homocysteine level, and more severe WML.

Relationship Between Gene Polymorphism of Methylenetetrahydrofolate Reductase C677T and Left Ventricular Hypertrophy in Chinese Patients with Chronic Kidney Disease

OBJECTIVE

This study aimed to investigate the relationship between the gene polymorphism of methylenetetrahydrofolate reductase (MTHFR) C677T and left ventricular hypertrophy (LVH) in patients with chronic kidney disease (CKD).

METHODS

A total of 763 Chinese patients with CKD undergoing genetic testing were included in the study. The association between the gene polymorphism of MTHFR C677T and echocardiographic parameters was analyzed through univariate and multivariate analyses.

RESULTS

We found a remarkably positive association between MTHFR C677T gene polymorphism and LVH indexes, including interventricular septal thickness (F = 3.8; P = .022), left ventricular posterior wall thickness (F = 3.0; P = .052), left ventricular mass (F = 3.9; P = .022), and left ventricular mass index (F = 2.6; P = .075). After adjusting for the potential confounders linking the polymorphism,we found that the positive association between the polymorphism and LVH indexes still existed in patients with CKD in some multiple linear regression models (P <.05).

CONCLUSION

MTHFR C677T gene polymorphism may be a genetic susceptibility marker for the development of LVH in patients with CKD.

Methylenetetrahydrofolate reductase polymorphisms as genetic markers to predict homocysteinemia and clinical severity in sickle cell disease

Aim: The present study observed the relationship between the methylenetetrahydrofolate reductase genotypes and clinical outcome in children with sickle cell disorder. Methodology: A total of 249 children were recruited for the study and evaluated clinically for calculating severity score, homocysteine levels and C677T and A1298C genotyping. Results: The frequencies of variant genotypes were 28.1% CT/TT677 and 69.1% AC/CC1298. Plasma homocysteine was significantly elevated in variant groups (p < 0.001). Both the genotypes accorded significant association with homocysteinemia (p < 0.001). Vascular crisis (p = 0.04), frequency of hospitalization (p < 0.001) and severity score (p = 0.02) revealed association with C677T and not with A1298C. The CT/TT677 genotypes showed 3.39-times (p = 0.032) increase in a higher score for severity. Conclusion: C677T depicted significant association with clinical severity in study population.

Possible roles of methylenetetrahydrofolate reductase polymorphism and folate status in patients with early hepatitis C virus genotype 4

BACKGROUND AND STUDY AIMS

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. In Egypt, 92.5% of HCV infection cases reportedly involve infection with HCV genotype 4. HCV infection may induce liver steatosis directly and indirectly. Host genetic polymorphisms may also contribute to the pathogenesis of steatosis. Folate deficiency indirectly cuase liver damage. Folate status is mostly affected by MTHFR C677T polymorphism. The pathophysiology of thrombocytopenia (TCP) in HCV infection remains unclear. Thus, the present study investigated the roles and consequences of MTHFR C677T SNP and folate status in patients with early HCV genotype 4 infection and their relation with steatosis and thrombocytopenia.

PATIENTS AND METHODS

Fifty patients with the HCV genotype 4 and 50 healthy controls were enrolled in the study. All the participants underwent laboratory, demographic, and anthropomorphic examinations. Serum folate level was determined, and genomic analysis of MTHFR C677T SNP was performed.

RESULTS

No significant difference in allelic frequency of MTHFR C677T was observed between patients and controls. However, significantly lower serum folate level, hemoglobin level, and platelet count were found in patients than controls (p = 0.014, p = 0.005, and p = 0.001, respectively). The cholesterol, triglyceride, and high-density lipoprotein levels were also significantly lower in patients than controls (p < 0.001, p = 0.001, and p < 0.001, respectively), whereas the low-density lipoprotein level was significantly higher in patients (p < 0.001). Patients harboring the MTHFR CT genotype had a significantly lower serum folate level (p = 0.033) than the controls. Among the patients with HCV infection, those with the TT genotype had the highest body mass index (p = 0.003) and levels of cholesterol, triglyceride, and high-density lipoprotein (p = 0.007, p = 0.025, and p = 0.040, respectively).

CONCLUSION

MTHFR C677T SNP may contribute to the development of complications associated with early HCV genotype 4 infection, such as dyslipidemia and decreased folate levels.

Distribution of Methionine Synthase Reductase (MTRR) Gene A66G Polymorphism in Indian Population

Methionine synthase reductase (MTRR) is an important enzyme of the folate/homocysteine pathway. It is responsible for regulation of methionine enzyme by reductive methylation. A common variant A66G is reported in the FMN-binding domain of the MTRR gene, which leads to substitution of isoleucine by methionine (I22M) in MTRR enzyme with reduced activity. Reduced catalytic activity of enzyme leads to high homocysteine concentration in blood and increases risk for numerous diseases. The frequency of A66G polymorphism varies in different ethnic groups. The present study has been designed to evaluate the frequency of MTRR A66G gene polymorphism in the Eastern UP population by PCR-RFLP method. Along with this we also performed a meta-analysis to evaluate the global prevalence of this polymorphism. Databases were screened to identified the eligible studies. The prevalence of the G allele and GG genotype was determined by the use of prevalence proportion with 95% CI. Open meta-analyst software was used for the meta-analysis. Total 1000 blood samples were analyzed, the frequencies of A and G alleles were 0.35 and 0.65 respectively. Meta-analysis results revealed that the prevalence of G allele and GG genotype were 49.4% (95% CI 40.6-58.1, p ≤ 0.001) and 24.3% (95% CI 17.8-30.9, p ≤ 0.001) respectively. In sub-group meta-analysis, the lowest frequency of G allele was found in South America (32.7%; 95% CI 14.1-51.3, p ≤ 0.001), and highest in Asia (56.4%; 95% CI 39.5-73.3, p ≤ 0.001). The results of the meta-analysis showed that the Asian population has the highest frequency of G allele and highest frequency of the GG genotype was found in the European population.

Association Between MTHFR C677T Polymorphism and Susceptibility to Autism Spectrum Disorders: A Meta-Analysis in Chinese Han Population

Prior studies have examined the influence of MTHFR C677T on autism susceptibility, however, there are no consensus conclusions and specific analyses of a Chinese population. This meta-analysis included a false-positive report probability (FPRP) test to comprehensively evaluate the association of MTHFR C677T polymorphism with autism susceptibility among a Chinese Han population. A large-scale literature retrieval was conducted using various databases including PubMed, Embase, Wan Fang, and the Chinese National Knowledge Infrastructure (CNKI) up to July 31, 2020, with a total of 2,258 cases and 2,073 controls included. The strength of correlation was assessed by odds ratios (ORs) and 95% confidence intervals (95% CIs). MTHFR C677T showed a significant correlation with increased ASD susceptibility under all genetic models (T vs. C, OR = 1.89, 95% CI 1.28 to 2.79; TT vs. CC: OR = 2.44, 95% CI 1.43 to 4.15; CT vs. CC, OR = 1.73; 95% CI 1.19 to 2.51; CT + TT vs. CC: OR = 2.03, 95% CI 1.31 to 3.15; TT vs. CT + CC, OR = 1.95, 95% CI 1.21 to 3.13). Stratification analysis by region also revealed a consistent association in the Northern Han subgroup, but not in the Southern Han subgroup. Pooled minor allele frequency (MAF) of 30 studies were 45% in Northern Han and 39% in Southern Han. To avoid a possible "false positive report," we further investigated the significant associations observed in the present meta-analysis using the FPRP test, which consolidated the results. In conclusion, MTHFR C677T polymorphism is associated with the increased risk of autism in China, especially in Northern Han. For those mothers and children who are generally susceptible to autism, prenatal folate and vitamin B12 may reduce the risk that children suffer from autism, especially in Northern Han populations. In the future, more well-designed studies with a larger sample size are expected.

Prevalence of methylenetetrahydrofolate reductase gene polymorphisms (C677T, and A1298C) among Saudi children receiving dental treatment

BACKGROUND

Methylenetetrahydrofolate reductase, the encoded by the MTHFR gene, plays a crucial role in converting the amino acid homocysteine to methionine. Two polymorphisms of the MTHFR gene, C677T and A1298C, reportedly reduce enzyme activity, resulting in hyperhomocysteinemia. Patients with C677T and A1298C polymorphisms may be at higher risk for developing abnormal hyperhomocysteinemia, which has been linked to catastrophic neurological including fatal outcomes.

OBJECTIVE

Determine the prevalence of the MTHFR gene variants C677T and A1298C among pediatric dental patients treated at King Abdulaziz University Hospital.

DESIGN

Cross-sectional.

SETTING

Clinics of pediatric dentistry department.

SUBJECTS AND METHODS

Healthy Saudi children 6-12 years old with no known allergies were screened for eligibility between May and December 2019. A single investigator collected saliva samples. The MTHFR C677T and A1298C polymorphisms were analyzed using polymerase chain reaction and restriction fragment length polymorphism.

MAIN OUTCOME MEASURE

The prevalence of MTHFR gene variants (C677T and A1298C) among the subjects.

SAMPLE SIZE

138.

RESULTS

MTHFR C677T polymorphism was present in 36.2% of the sample and 90.0% of children carrying this allele were heterozygotes. MTHFR A1298C polymorphism was present in 91.3% of the sample and 77.0% of the children carrying this allele were heterozygotes. No linkage disequilibrium between MTHFR C677T and MTHFR A1298C was observed within this sample.

CONCLUSIONS

Our study found a high frequency of the MTHFR A1298C genotype, which was substantially more abundant than expected based on a Hardy-Weinberg distribution. Therefore, caution is advised in using N2O in Saudi children as the increased prevalence of this MTHFR allele may increase the incidence of serious adverse effects among these children.

LIMITATIONS

Further studies are recommended with a larger sample size from randomly selected hospitals from different regions of Saudi Arabia.

CONFLICT OF INTEREST

None.

The recent effects of small dose of folic acid on lipoprotein-associated phospholipase A2 and systolic blood pressure variability in coronary heart disease patients with hyperhomocysteinemia: A single-center prospective cohort study

To Investigate the recent effects of small dose of folic acid on lipoprotein-associated phospholipase A2 (LP-PLA2) and systolic blood pressure variability in coronary heart disease (CHD) patients with hyperhomocysteinemia.In this prospective cohort study, a total of 167 CHD patients with hyperhomocysteinemia were consecutively enrolled, and they were divided into Group A (without folic acid intervention, n = 99), Group B (with 0.4 mg of folic acid intervention, n = 34), Group C (0.8 mg of folic acid intervention, n = 34). General information, fasting blood glucose, and blood lipid, folic acid, homocysteine, Lp-PLA2, and blood pressure variability were compared among 3 groups. The above indicators were reviewed after 3 months of treatment.There were no statistically significant differences of age, gender, blood pressure, incidence of type 2 diabetes mellitus, fasting blood glucose, folic acid, homocysteine, Lp-PLA2, total cholesterol, 3 acyl glycerin, apolipoprotein B, lipoprotein (a), high density lipoprotein cholesterol, and low density lipoprotein cholesterol were found among 3 groups (P > .05); however, after being treated for 3 months, there was statistically significant difference in folic acid among 3 groups (P < .05), there was statistically significant difference in apolipoprotein A between Group A and Group B (t = 0.505, P = .039), and also between Group A and Group C (t = 0.052, P = .017). There were statistically significant differences in Lp-PLA2 (t = 24.320, P = .016) and systolic blood pressure variability (t = 0.154, P = .018) between Group A and Group C.For CHD patients with hyperhomocysteinemia, the higher dose (0.8 mg) of folic acid supplement was beneficial for increasing the apolipoprotein A, reducing the Lp-PLA2, and improving the systolic blood pressure variation, which might help to improve the prognosis in these patients.

Polymorphism of MTHFR C677T Gene and the Associations with the Severity of Essential Hypertension in Northern Chinese Population

Objective

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of homocysteine metabolism and is closely related to the occurrence of hypertension. The aim of this study was to investigate the polymorphism of the (MTHFR) C677T and the factors influencing the severity of hypertension. Material and Methods. A total of 985 subjects were enrolled to analyze the polymorphisms of the MTHFR C677T gene by polymerase chain reaction (PCR). 306 people with essential hypertension were selected from 985 subjects to estimate the severity of hypertension by the ordinal multivariate logistical regression model.

Results

The frequencies of CC, CT, and TT genotypes were 19.5%, 49.95%, and 30.46%, respectively. The allelic frequency of mutant T was 55.43%. The plasma homocysteine level of the homozygous TT in individuals was significantly higher than in those with CC or CT (P < 0.01). MTHFR677CT genotype, MTHFR677TT genotype, smoking, family history of hypertension, Hcy, and triglycerides (TG) were independent risk factors for the severity of hypertension (OR = 2.29, 2.24, 2.04, 1.81, 1.04, 1.26).

Conclusion

MTHFR gene, smoking, family history of hypertension, Hcy, and triglycerides could be important genetic and high-risk factors of the development of severe hypertension in northern Chinese. These factors will contribute to the identification of high-risk populations of hypertension and facilitate the development of hypertension control strategies.

Effect of folic acid combined with docosahexaenoic acid intervention on mild cognitive impairment in elderly: a randomized double-blind, placebo-controlled trial

PURPOSE

This study aimed to assess the effects of folic acid (FA) combined with a docosahexaenoic acid (DHA) intervention on the cognitive function and inflammatory cytokines in elderly subjects with mild cognitive impairment (MCI).

METHODS

This randomized, double-blind, placebo-controlled trial recruited 240 individuals with MCI in Tianjin, China, and randomly allocated into 4 groups: FA + DHA (FA 800 μg/d + DHA 800 mg/d), FA (FA 800 μg/d), DHA (DHA 800 mg/d), and placebo. Cognitive function, serum folate and homocysteine (Hcy), plasma DHA and inflammatory cytokines levels were measured at baseline and 6 months.

RESULTS

Daily oral FA, DHA and their combined use for 6 months significantly improved the full-scale intelligence quotient (FSIQ) and some subtests of Wechsler Adult Intelligence Scale compared to the placebo. The increases of FSIQ, arithmetic, picture completion scores in the FA group and picture completion, block design scores in the DHA group were significantly less than that in the FA combined DHA group (P < 0.05). Meanwhile, daily oral FA, DHA and their combined use for 6 months significantly decreased plasma inflammatory cytokines compared to the placebo. The changes of interleukin-1β levels in the FA group and interleukin-6 levels in the DHA group were significantly less than that in the FA + DHA group (P < 0.05).

CONCLUSIONS

Daily oral FA, DHA and their combined use for 6 months can significantly improve cognitive function and decrease plasma inflammatory cytokines in MCI individuals. The combination of FA and DHA was more beneficial than each individual nutrient on their own.

The Association Between Hyperhomocysteinemia and Thyroid Nodule Prevalence in an Adult Population

Background: Thyroid nodule is the most common disorder of thyroid. Metabolic syndrome was regarded as an important factor for the prevalence of thyroid nodule. Homocysteine has been shown to be related to metabolic syndrome, inflammation, and several common cancers. In this study, we aimed to investigate the relationship between serum homocysteine and the prevalence of thyroid nodule. Materials and Methods: This was a cross-sectional study that included 2040 adults in a health checkup population in Beijing Chao-yang hospital. Thyroid ultrasound data, together with anthropometric characteristics, metabolic parameters, and serum homocysteine, were recorded respectively. Results: Hyperhomocysteinemia (defined as serum homocysteine ≥15 μmol/L) was detected in 452 participants (21.91%). Thyroid nodule prevalence was significantly higher in hyperhomocysteinemia participants than in normal homocysteine participants (52.57% vs. 45.16%, P = 0.006). Logistic regression analysis revealed that age [odds ratio (OR) 1.054; P < 0.001], female gender (OR 2.242; P < 0.001), body mass index (OR 1.050; P < 0.001), and serum homocysteine level (OR 1.022; P = 0.001) were the independent risk factors for thyroid nodule. Conclusions: Subjects with hyperhomocysteinemia have significantly higher thyroid nodule prevalence. Homocysteine is an independent risk factor for thyroid nodule. It implies that individuals with hyperhomocysteinemia have higher susceptibility to thyroid nodule.

Micronutrients in support to the one carbon cycle for the modulation of blood fasting homocysteine in PCOS women

PURPOSE

Fasting blood homocysteine is increased in PCOS women and is involved in several of its co-morbidities including cardiovascular disease and infertility. Corrective interventions based on the administration of supra-physiologic doses of folic acid work to a low extent. We aimed to test an alternative approach.

METHODS

This was a prospective, randomized, parallel group, open label, controlled versus no treatment clinical study. PCOS women aged > 18, free from systemic diseases and from pharmacological treatments were randomized with a 2:1 ratio for treatment with activated micronutrients in support to the carbon cycle (Impryl, Parthenogen, Switzerland-n = 22) or no treatment (n = 10) and followed-up for 3 months. Fasting blood homocysteine, AMH, testosterone, SHBGs, and the resulting FTI were tested before and at the end of the follow-up.

RESULTS

The mean baseline fasting blood homocysteine was above the normal limit of 12 μMol/L and inversely correlated with SHBG. AMH was also increased, whereas testosterone, SHBG, and FTI were within the normal limit. The treatment achieved a significant reduction of homocysteine, that did not change in the control group, independently of the starting value. The treatment also caused an increase of AMH and a decrease of SHBGs only in the subgroup with a normal homocysteine at baseline.

CONCLUSIONS

In PCOS ladies, blood homocysteine is increased and inversely correlated with the SHBGs. Physiologic amounts of activated micronutrients in support to the carbon cycle achieve a reduction virtually in all exposed patients. Whether this is of clinical benefit remains to be established.

A molecular-beacon-based asymmetric PCR assay for detecting polymorphisms related to folate metabolism

BACKGROUND

Polymorphisms (rs1801133 or C677T; rs1801131 or A1298C) of the MTHFR gene and rs1801394 (A66G) of the MTRR gene are important genetic determinants of folate metabolism. A convenient, sensitive, and reliable method is required to detect polymorphisms for the precise supplementation of folate.

METHODS

A rapid detection method based on molecular beacon probes that can detect rs1801133, rs1801131, and rs1801394 simultaneously was developed in this study. Specific primers and probes were designed, and the amplification system and conditions were optimized. We applied our method to a group of 500 unrelated women of gestational age in the Dongguan region of Guangdong Province in China. The clinical performance of this assay was evaluated by testing 94 samples in comparison with Sanger sequencing.

RESULTS

The molecular-beacon-based PCR assay we established is extremely sensitive, with a detection limit of 2 ng/μL of genomic DNA, and validated by direct sequencing in a blind study with 100% concordance.

CONCLUSION

The results demonstrate that our molecular-beacon-based asymmetric PCR assay is an easy, reliable, high-yield, and cost-effective method for the simultaneous detection of three polymorphisms related to folate metabolism. It could help evaluate the risk of perinatal-neonatal neural tube malformation, pregnancy hypertension, and other diseases and guide the individualized supplementation of folic acid. Data on the spectrum of mutations in the Dongguan District in this study are beneficial for guiding the supplementation of folic acid.

Design and Evaluation of a Method for Testing Polymorphisms of Folate-Related Genes Using the Luminex Liquichip System

Purpose: The methylene tetrahydrofolate reductase (MTHFR) C677T, MTHFR A1298C, and the methionine synthase reductase (MTRR) A66G polymorphisms are the three most common folate metabolism-related loci in the Chinese population. They are associated with numerous birth defects or congenital diseases. To facilitate screening and genetic counseling, we established a method for the simultaneous detection of these three polymorphisms using the Luminex liquid suspension chip and multiple asymmetric polymerase chain reactions (PCRs). Materials and Methods: The three polymorphisms were amplified by multiplex PCR with biotinylated primers, followed by hybridization with six probe-linked magnetic microspheres. The mean fluorescent intensity value in each microsphere was detected by Luminex Magpix for polymorphism detection in 150 samples and confirmed by sequencing. Results: The consistency between the Luminex liquid suspension chip method and sequencing was 100%. Among the 150 randomized samples, the minor allele frequency (MAF) of MTHFR C677T was 0.41, which was the most common variant allele, followed by MTRR A66G (MAF = 0.24), and finally MTHFR A1298C (MAF = 0.19). Conclusion: The Luminex liquid suspension chip method can replace sequencing to analyze the MTHFR C677T, MTRR A1298C, and MTRR A66G loci simultaneously as a rapid, convenient, accurate, and stable method for large-scale testing.

Association of MTHFR gene polymorphisms with pancreatic cancer: meta-analysis of 17 case-control studies

BACKGROUND

Pancreatic cancer (PC) is a seriously malignant tumor with a low 5-year survival rate. The relationship between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and PC has been reported by several studies. However, the results were controversial. Thus, we conducted a meta-analysis to summarize available data on MTHFR gene and PC.

METHODS

We searched PubMed, Embase, Web of Science, Wanfang, CNKI databases prior to July 2019. Data were analyzed by RevMan 5.3 and STATA 12.0 software. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the strength of the association. Subgroup analysis, sensitivity analysis and assessment of publication bias were performed in this study.

RESULTS

Ten articles with 17 reports (10 for C677T, 7 for A1298C) were eligible for inclusion in the meta-analysis (1864 cases and 3165 controls for C677T, and 1488 cases and 1946 controls for A1298C). Our meta-analysis detected that C677T was associated with PC for three genetic models (allele model: OR = 1.24, 95% CI: 1.00-1.53, P = 0.047; recessive model: OR = 1.39, 95% CI: 1.04-1.86, P = 0.027; homozygous model: OR = 1.60, 95% CI: 1.04-2.45, P = 0.034). In the stratified analyses according to ethnicity, source of controls and genotyping method, significant association was observed in genotyping method subgroup. For the A1298C polymorphism, no significant association was observed either in overall analysis or in subgroup analysis under all genetic models.

CONCLUSIONS

MTHFR gene C677T rather than A1298C polymorphism may be associated with PC. Larger sample size studies should be performed to find the association between MTHFR gene and PC.

Whole Genome Analyses of Chinese Population and De Novo Assembly of A Northern Han Genome

To unravel the genetic mechanisms of disease and physiological traits, it requires comprehensive sequencing analysis of large sample size in Chinese populations. Here, we report the primary results of the Chinese Academy of Sciences Precision Medicine Initiative (CASPMI) project launched by the Chinese Academy of Sciences, including the de novo assembly of a northern Han reference genome (NH1.0) and whole genome analyses of 597 healthy people coming from most areas in China. Given the two existing reference genomes for Han Chinese (YH and HX1) were both from the south, we constructed NH1.0, a new reference genome from a northern individual, by combining the sequencing strategies of PacBio, 10× Genomics, and Bionano mapping. Using this integrated approach, we obtained an N50 scaffold size of 46.63 Mb for the NH1.0 genome and performed a comparative genome analysis of NH1.0 with YH and HX1. In order to generate a genomic variation map of Chinese populations, we performed the whole-genome sequencing of 597 participants and identified 24.85 million (M) single nucleotide variants (SNVs), 3.85 M small indels, and 106,382 structural variations. In the association analysis with collected phenotypes, we found that the T allele of rs1549293 in KAT8 significantly correlated with the waist circumference in northern Han males. Moreover, significant genetic diversity in MTHFR, TCN2, FADS1, and FADS2, which associate with circulating folate, vitamin B12, or lipid metabolism, was observed between northerners and southerners. Especially, for the homocysteine-increasing allele of rs1801133 (MTHFR 677T), we hypothesize that there exists a "comfort" zone for a high frequency of 677T between latitudes of 35-45 degree North. Taken together, our results provide a high-quality northern Han reference genome and novel population-specific data sets of genetic variants for use in the personalized and precision medicine.

MTHFR Gene Mutations Correlate with White Matter Disease Burden and Predict Cerebrovascular Disease and Dementia

The incidence of dementia is on the rise and expected to continue to increase in the foreseeable future. Two of the most common subtypes of dementia are Alzheimer's subtype and vascular dementia. Hyperhomocysteinemia has been shown to serve as a risk factor for dementia due to an associated blood-brain barrier dysfunction and subsequent small-vessel disease pathology. There are varying causes for hyperhomocysteinemia, including genetic and dietary, among others. We highlight the importance of identifying hyperhomocysteinemia as a potential etiologic and therapeutic target for the most common subtypes of dementia.

Effects of maternal folic acid supplementation during pregnancy on infant neurodevelopment at 1 month of age: a birth cohort study in China

PURPOSE

This study aimed to explore effects of maternal folic acid (FA) supplementation during pregnancy on neurodevelopment in 1-month-old infants and to determine whether effects may be related to maternal circulating inflammatory cytokine concentrations.

METHODS

This birth cohort study recruited 1186 mother-infant pairs in Tianjin, China, between July 2015 and July 2017. The women completed interviewer-administered questionnaires on their lifestyles and FA supplementation during pregnancy. Neurodevelopment was assessed in 1-month-old infants using a standard neuropsychological examination table. In 192 women, serum homocysteine (Hcy) and inflammatory cytokine concentrations were measured at 16-18 weeks of gestation.

RESULTS

The infants whose mothers took FA supplements during pregnancy had a significantly higher development quotient (DQ) compared with those whose mothers were non-users (P < 0.05). After adjustment for maternal characteristics, supplementary FA use for 1-3 months, 3-6 months, and > 6 months were associated with the increases of 7.7, 11.0, and 7.4 units in the scale of infant DQ score compared with women reporting no supplement use, respectively (P < 0.05). FA supplementation was associated with a decreased serum concentration of Hcy (β = [Formula: see text] 0.19), which was correlated with women's serum inflammatory cytokine concentrations at 16-18 weeks of gestation (β = 0.57). Serum inflammatory cytokine concentrations were inversely related to DQ score in the 1-months-old offspring (β = [Formula: see text] 0.22).

CONCLUSIONS

Maternal FA supplementation during pregnancy favors neurodevelopment in the offspring at 1-month-old. This association may be mediated by changes in serum Hcy and inflammatory cytokine concentrations throughout pregnancy.

The Role of Polymorphism Gen Methylene Tetra Hydrofolate Reductase (MTHFR) C677T in Ischaemic Stroke Patients with and Without Hypertension

BACKGROUND:

Stroke is a leading cause of disability and remains the second leading cause of death in the world. Some of the pathogenesis of stroke are interactions between genetic and acquired risk factors, the interaction is related with the atherosclerotic which is the main pathogenesis of ischaemic stroke. Previous studies demonstrated an association between methylene tetra hydro folate reductase (MTHFR) genotype and ischaemic stroke; the MTHFR C677T genotype is one of the independent risk factor.

AIM:

This study aims to know about the role of polymorphism gen MTHFR C677T in ischaemic stroke patients with and without hypertension.

METHODS:

This study is a cross-sectional study, the sample was taken consecutively, after approval by the Medical Faculty Science’s Ethics Committee at University Sumatera Utara. All sample matched with inclusion and exclusion criteria, demography data and blood sample were taken. Demography data were analysed using descriptive statistic.

RESULTS:

Of the 106 ischaemic stroke patients were divided into two groups, the first group is patients with hypertension (53 patients), and the second group is without hypertension (53 patients). We have done the PCR- RFLP to all the patients, we got 78 patients with 677CC of MTHFR genotype, 23 patients with 677CT genotype and 5 patients with 677TT genotype. We found polymorphism C677T is more frequent in ischaemic stroke patients with hypertension (16 patients; 69.5%), and all the patient with 677TT genotype are an ischaemic stroke with hypertension (5 patients; 100%).

CONCLUSION:

We concluded that polymorphism MTHFR C677T have an important role in hypertension and ischaemic stroke.

Association of Single Nucleotide Polymorphisms (SNPs) in Genes Encoding for Folate Metabolising Enzymes with Glioma and Meningioma in Indian Population

Background:

The association of primary brain tumors with Single Nucleotide polymorphisms (SNPs) in genes of folate metabolising enzymes have been reported to vary among different ethnic population. Here, we have studied the association of SNPs of folate metabolizing genes with the primary brain tumors (glioma and meningioma) in North Indian population.

Methods:

SNPs of genes coding for folate metabolizing enzymes was carried out in 288 study population from North India [Glioma (n=108), Meningioma (n=76) and healthy-control (n=104)]. The allele-specific polymerase chain reaction (ARMS-PCR) was used to analyse the SNP A1298C of the MTHFR (Methylenetetrahydrofolate-reductase) and the SNP A66G of the methionine synthase reductase (MTRR) genes. The PCR-RLFP (Restriction Fragment Length Polymorphism) was used to analyse the SNP C677T of the Methylene tetrahydrofolate-reductase and the SNP A2756G of the methionine-synthase (MTR) genes. Serum homocysteine, vitamin B₁₂ and folate levels were evaluated in controls/patients serum using Chemiluminescence immunoassay and the levels were correlated with SNPs genotype.

Results:

The CC genotype of MTHFR A1298C was observed to have reduced risk of having meningioma than AA genotype (odd ratio=0.62, 95%CI 0.32-0.97, p=0.03). Similarly, the AG genotype of MTRR A66G showed reduced risk of glioma than AA genotype (odd ratio=0.56, 95%CI 0.32-0.97, p=0.039). Furthermore, in patients with AA genotype of MTR A2756G and CT genotype of MTHFR C677T showed higher serum homocysteine level than GG genotype (8.6 µmol/L, p=0.048) and CC genotype (11.2µmol/L, p=0.039) respectively.

Conclusion:

Our findings provide an insight into the risk association of SNPs in MTHFR A1298C and MTRR A66G genes with glioma/meningioma patients. Further studies are needed to evaluate their clinical implications.

Interaction of MTHFR C677T polymorphism with smoking in susceptibility to diabetic nephropathy in Chinese men with type 2 diabetes

We investigated the interaction of MTHFR C677T polymorphism (rs1801133) with smoking in susceptibility to diabetic nephropathy (DN) in Chinese men with type 2 diabetes mellitus (T2DM). We studied 655 Chinese men with T2DM, who were divided into two groups (321 with DN and 334 without DN). The genotype of MTHFR C677T polymorphism was detected by real-time polymerase chain reaction. MTHFR TT genotype carried a higher risk of DN compared with the CC genotype (OR = 2.05; P = 0.002). The T allele showed marked association with DN development in patients who smoked, using additive, recessive, and dominant models (OR = 1.60, 1.83, and 1.88, respectively; P = 0.006, 0.002, and 0.04, respectively), which was not observed in the nonsmoking group. Patients with TT and CT genotypes, who smoked had a higher risk of DN compared with the control group (non-smoking with CC genotype; OR = 3.73 and 2.28, respectively; P < 0.001 and P = 0.004, respectively), whereas the other groups were not observed. In conclusion, the T allele of rs1801133 may be a risk factor for DN in Chinese men with T2DM, and synergy appears to exist between the MTHFR rs1801133 and smoking in susceptibility to DN.

Gene-Metabolite Interaction in the One Carbon Metabolism Pathway: Predictors of Colorectal Cancer in Multi-Ethnic Families

For personalized healthcare, the purpose of this study was to examine the key genes and metabolites in the one-carbon metabolism (OCM) pathway and their interactions as predictors of colorectal cancer (CRC) in multi-ethnic families. In this proof-of-concept study, we included a total of 30 participants, 15 CRC cases and 15 matched family/friends representing major ethnic groups in southern California. Analytics based on supervised machine learning were applied, with the target variable being specified as cancer, including the ensemble method and generalized regression (GR) prediction. Elastic Net with Akaike's Information Criterion with correction (AICc) and Leave-One-Out cross validation GR methods were used to validate the results for enhanced optimality, prediction, and reproducibility. The results revealed that despite some family members sharing genetic heritage, the CRC group had greater combined gene polymorphism-mutations than the family controls (p < 0.1) for five genes including MTHFR C677T, MTHFR A1298C, MTR A2756G, MTRR A66G, and DHFR 19bp. Blood metabolites including homocysteine (7 µmol/L), methyl-folate (40 nmol/L) with total gene mutations (≥4); age (51 years) and vegetable intake (2 cups), and interactions of gene mutations and methylmalonic acid (MMA) (400 nmol/L) were significant predictors (all p < 0.0001) using the AICc. The results were validated by a 3% misclassification rate, AICc of 26, and >99% area under the receiver operating characteristic curve. These results point to the important roles of blood metabolites as potential markers in the prevention of CRC. Future intervention studies can be designed to target the ways to mitigate the enzyme-metabolite deficiencies in the OCM pathway to prevent cancer.

Personalized Nutrition-Genes, Diet, and Related Interactive Parameters as Predictors of Cancer in Multiethnic Colorectal Cancer Families

To personalize nutrition, the purpose of this study was to examine five key genes in the folate metabolism pathway, and dietary parameters and related interactive parameters as predictors of colorectal cancer (CRC) by measuring the healthy eating index (HEI) in multiethnic families. The five genes included methylenetetrahydrofolate reductase (MTHFR) 677 and 1298, methionine synthase (MTR) 2756, methionine synthase reductase (MTRR 66), and dihydrofolate reductase (DHFR) 19bp, and they were used to compute a total gene mutation score. We included 53 families, 53 CRC patients and 53 paired family friend members of diverse population groups in Southern California. We measured multidimensional data using the ensemble bootstrap forest method to identify variables of importance within domains of genetic, demographic, and dietary parameters to achieve dimension reduction. We then constructed predictive generalized regression (GR) modeling with a supervised machine learning validation procedure with the target variable (cancer status) being specified to validate the results to allow enhanced prediction and reproducibility. The results showed that the CRC group had increased total gene mutation scores compared to the family members (p < 0.05). Using the Akaike’s information criterion and Leave-One-Out cross validation GR methods, the HEI was interactive with thiamine (vitamin B1), which is a new finding for the literature. The natural food sources for thiamine include whole grains, legumes, and some meats and fish which HEI scoring included as part of healthy portions (versus limiting portions on salt, saturated fat and empty calories). Additional predictors included age, as well as gender and the interaction of MTHFR 677 with overweight status (measured by body mass index) in predicting CRC, with the cancer group having more men and overweight cases. The HEI score was significant when split at the median score of 77 into greater or less scores, confirmed through the machine-learning recursive tree method and predictive modeling, although an HEI score of greater than 80 is the US national standard set value for a good diet. The HEI and healthy eating are modifiable factors for healthy living in relation to dietary parameters and cancer prevention, and they can be used for personalized nutrition in the precision-based healthcare era.

Prevalent genotypes of methylenetetrahydrofolate reductase (MTHFR) in recurrent miscarriage and recurrent implantation failure

OBJECTIVE

To evaluate the association of two common methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms with recurrent miscarriage (RM) and repeated implantation failure (RIF) METHODS: The study comprised of 521 patients, with a history of RM (n = 370) or RIF (n = 151). One hundred forty-four women with fallopian tube blockages who had successfully conceived after the first in vitro fertilization embryo transfer treatment served as the control group. The MTHFR alleles, genotypes, and haplotypes were assessed in different groups.

RESULTS

There was no difference in allele frequency and distribution of MTHFR polymorphisms between case and control patients. The 1298AA genotype was represented in a higher frequency, and 1298AC genotype was significantly lower in subfertile group when compared to the control group. A significant relationship was found between the 1298AC genotype and the RIF subgroup. The haplotype 677CC/1298AA was overrepresented in the RM subgroup (> 2 times) and haplotype 677CC/1298AC was underrepresented in the RIF subgroup (P < 0.05). Nevertheless, these two haplotypes were not connected to fertilization and embryo cleavage rates.

CONCLUSION

Our findings indicate that the MTHFR gene polymorphism might play a role in the etiology of patients with RM or RIF. No adverse effects of different MTHFR haplotypes on embryo development were detected. Further studies on the biological role are needed to better understand the susceptibility to pregnancy complications.