Association between MTHFR C677T/A1298C and susceptibility to autism spectrum disorders: a meta-analysis

Background Autism spectrum disorder (ASD) is becoming increasingly prevalent of late. Methylenetetrahydrofolate reductase (MTHFR) has a significant role in folate metabolism. Owing to the inconsistencies and inconclusiveness on the association between MTHFR single nucleotide polymorphism (SNP) and ASD susceptibilities, a meta-analysis was conducted to settle the inconsistencies. Methods For this meta-analysis, a total of 15 manuscripts published up to January 26, 2020, were selected from PubMed, Google Scholar, Medline, WangFang, and CNKI databases using search terms “MTHFR” OR “methylenetetrahydrofolate reductase” AND “ASD” OR “Autism Spectrum Disorders” OR “Autism” AND “polymorphism” OR “susceptibility” OR “C677T” OR “A1298C”. Results The findings of the meta-analysis indicated that MTHFR C677T polymorphism is remarkably associated with ASD in the five genetic models, viz., allelic, dominant, recessive, heterozygote, and homozygote. However, the MTHFR A1298C polymorphism was not found to be significantly related to ASD in the five genetic models. Subgroup analyses revealed significant associations of ASD with the MTHFR (C677T and A1298C) polymorphism. Sensitivity analysis showed that this meta-analysis was stable and reliable. No publication bias was identified in the associations between MTHFRC677T polymorphisms and ASD in the five genetic models, except for the one with regard to the associations between MTHFRA1298C polymorphisms and ASD in the five genetic models. Conclusion This meta-analysis showed that MTHFR C677T polymorphism is a susceptibility factor for ASD, and MTHFR A1298C polymorphism is not associated with ASD susceptibility.

The association of methylene tetrahydrofolate reductase (MTHFR) A1298C gene polymorphism, homocysteine, vitamin B12, and folate with coronary artery disease (CAD) in the north of Iran

BackgroundWe pursued to find out the possible association of Methylene tetrahydrofolate reductase (MTHFR) A1298C gene polymorphism, blood homocysteine, vitamin B12, and folate with Coronary artery disease (CAD) in the study population in Guilan, north of Iran.Material and MethodsNinety patients with CAD and 76 healthy controls were evaluated. MTHFR A1298C polymorphism and its genotype frequency, the plasma level of homocysteine, vitamin B12 and folate were evaluated by using ARMS-PCR, ELISA, and Chemiluminescence methods, respectively.ResultsThe frequency of genotypes, A, AC and CC in CAD were 40, 35.6, 24.4%, respectively which was significantly different (p=0.016) from the control group that were 26.3, 57.9 and 15.8%, respectively. The serum level of vitamin B12 and folate in genotype A1298C were not statistically significant between two groups (p>0.05), however, the plasma homocysteine in patients with CAD was remarkably higher than the control group (p<0.001). Additionally, in CAD patients the plasma level of homocysteine in the AC genotype was significantly higher than the control subjects (p=0.005).ConclusionIt is thus concluded that MTHFR A1298C gene polymorphism is associated with CAD. It seems that the AC genotype of MTHFR A1298C polymorphism might have a protective effect on CAD.

The association of MTHFR A1298C polymorphism with cervical cancer: An Updated Meta-Analysis Involving 2835 Subjects

Background Published data have reported the relationships between MTHFR A1298C polymorphisms and cervical cancer susceptibility. However, the conclusions of these findings lack consistency.Methods A comprehensive literature search was performed using Web of Science, PubMed, EMBASE, Cochrane library, Wan Fang and CNKI databases. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the correlation of MTHFR A1298C polymorphism and cervical cancer risk. Fixed-effects or random effects models was adopted according to heterogeneity test.Results A total of nine studies (1145 cases and 1690 controls) were included in this meta-analysis. Pooled data revealed that MTHFR A1298C polymorphism was significantly associated with an increased risk of cervical cancer in the allele model (P=0.028); the recessive model (P=0.028); and the heterozygous model (P=0.031).Conclusions Our results revealed that MTHFR A1298C polymorphism was associated with risk of cervical cancer.

Meta-analysis of the relationship between methylenetetrahydrofolate reductase C677T and A1298C polymorphism and venous thromboembolism in the Caucasian and Asian

Recent years, it is a highly debated topic that whether methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and A1298C polymorphism could increase susceptibility to venous thromboembolism (VTE) in the Asian and Caucasian. Therefore, we expect to settle that controversy evidentially. Basic methods: Electronic databases (Pubmed, embase, Cochrane library, scopus, OvidSP, Wiley Online library, Springer link, EBSCO, Elsevier Science Direct, Google scholar) without date limitation were searched. Crude odds ratio (OR) along with 95% confidence interval (95% CI) was calculated to assess the association quantitatively. Finally, a total of 37 eligible studies were included, containing 31 for MTHFR C677T polymorphism and 6 for MTHFR A1298C polymorphism. The pooled results suggested that MTHFR C677T mutation may increase susceptibility to VTE in reverse recessive model (CC+CT vs TT): OR = 0.68 (0.56, 0.83), reverse dominant model (CC vs CT +TT): OR = 0.82 (0.72, 0.94), heterozygote model (CT vs TT): OR = 0.65 (0.52, 0.81), homozygote model (CC vs TT): OR = 0.73 (0.60, 0.89) and allele model (C vs T): OR = 0.80 (0.71, 0.90). Subgroup analysis about Asian also support that results, but Caucasian group not. In addition, MTHFR A1298C polymorphism may be not related to VTE in all genetic model. The results of meta-analysis indicated that MTHFR C677T polymorphism might increase the risk of VTE, especially in Asian population.

Association of MTHFR A1298C Polymorphism with Preterm Birth: A Meta-Analysis

Background: A few studies have been conducted to explore the association of MTHFR A1298C (rs1801131) polymorphism with preterm birth risk, the results remain inconsistent. Therefore, we conducted a meta-analysis to derive a more systematic estimation of the association. Method: Relevant studies were searched by PubMed, EMBASE, CNKI, and Google Scholar up to June 2018. The strength of the association of MTHFR A1298C polymorphism with preterm birth was calculated by odds ratios (OR) with 95% confidence interval (95%CI). Results: A total of nine case-control studies with 1,609 cases and 14,981 controls were included. Pooled results showed that there was no significant association between MTHFR A1298C polymorphism and preterm birth risk under all five genetic models in overall. However, in the stratified analysis of ethnicity, a significant association between MTHFR A1298C polymorphism and preterm birth risk was observed in the Asians under four genetic models, i.e., allele (C vs. A: OR = 0.960, 95% CI 0.543-0.871, P = 0.002), heterozygote (CA vs. AA: OR = 0.887, 95% CI 0.024-0.457, P = 0.003), dominant (CC+CA vs. AA: OR = 0.965, 95% CI 0.534 -0.935, P = 0.015) and recessive (CC vs. CA+AA: OR = 0.923, 95% CI 0.026-0491, P = 0.004), but not in Caucasians. Conclusion: This meta-analysis suggested that MTHFR A1298C polymorphism is not associated with preterm birth risk in overall population. However, MTHFR A1298C polymorphism plays an important role in preterm birth development in Asian population.

Methylenetetrahydrofolate reductase polymorphism and capecitabine-induced toxicity in patients with gastric cancer

Purpose: To evaluate the effect of methylenetetrahydrofolate reductase (MTHFR) polymorphism on toxicity in gastric cancer (GC) patients treated with capecitabine. Methods: One hundred and twenty-six GC patients were treated with capecitabine in the study. DNA from GC patients was genotyped for MTHFR A1298C using direct sequencing. Toxicity evaluations were graded. Clinical response was assessed. Results: In 87.3 % of the patients, capecitabine toxicity was observed. As for MTHFR A1298C polymorphism, 55.6 % patients who exhibited it were associated with reduced MTHFR activity. MTHFR A1298C was associated with capecitabine-related toxicity (p = 0.008); in addition, MTHFR A1298C was significantly associated with gastrointestinal toxicity (p = 0.026), but not with other types of toxicity. Conclusion: The findings suggest that MTHFR A1298C may be useful for predicting toxicity in GC patients receiving capecitabine treatment, especially gastrointestinal toxicity. Keywords: MTHFR, Polymorphism, Gastric cancer, Toxicity