Objective To determine the genotype distribution of methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C and methionine synthase reductase (MTRR) A66G involved in the folic acid biosynthetic pathway among Chinese Han women in Sichuan, so as to provide pregnant women with guidance of supplementing folic acid. Methods By means of Taqman-MGB, 2382 samples from Deyang region in Sichuan province were tested for detecting the genotype distributions and allele frequencies of MTHFR C677T, MTHFR A1298C and MTRR A66G polymorphisms, and then the results were compared with published data in Shandong, Henan and Hainan provinces. Results The allele frequencies of MTHFR C677T were 63.45 and 36.55, those of MTHFR A1298C were 78.20 and 21.80, and those of MTRR A66G were 72.81 and 27.19. There were significant differences in allele distribution of MTHFR C677T and A1298C between Sichuan Han women and other region population. Conclusion This study suggests that the polymorphism of MTHFR C677T and A1298C exhibits region heterogeneity. The polymorphisms of MTHFR may play a role in neural tube defects (NTDs) risk, so periconceptional folic acid supplementation and healthcare following gene polymorphism testing may be a powerful measure to decrease congenital malformations of the central nervous system.
ObjectiveTo evaluate the relationship between methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and efficacy of fluorouracil-based chemotherapy in patients with advanced gastric cancer (AGC). MethodsComputer retrieval in China Journal Full-text Database, Chinese Science and Technology Periodical Database, Wanfang database, Chinese Biomedical Literature Database, PubMed, EMbase, Cochrane Library and Web of Science Database (from their establishment to May 28, 2013) was performed to include case-control studies on MTHFR gene C677T polymorphism and sensitivity to fluorouracil-based chemotherapy in patients with advanced gastric cancer. Statistical analysis was done by using RevMan 5.1 software. ResultsSeven case-control studies with 775 patients were included. The meta-analysis showed that among MTHFR C677T genotypes, for TT vs. CC, OR=4.63, 95%CI (1.23, 17.4); and for CC+CT vs. TT, OR=0.21, 95%CI (0.06, 0.78). Subgroup analysis of Asian group showed that for TT vs. CC, OR=32.99, 95%CI (11.40,95.42); and for CC+CT vs. TT, OR=0.04, 95%CI (0.02, 0.10). Sensitivity analysis performed according to different detection methods showed that for TT vs. CC, OR=6.03, 95%CI (1.53, 23.72); and for CC+CT vs.TT, OR=0.17, 95%CI (0.04, 0.68). ConclusionPolymorphism of MTHFR C677T gene may be associated with sensitivity to fluorouracil-based chemotherapy in patients with AGC.
ObjectiveTo systematically review the association between C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene and the risk of unexplained recurrent spontaneous abortion (URSA). MethodsWe searched PubMed, EMbase, CBM, CNKI, VIP and WanFang Data from inception to May 2015 to collect case-control studies about the association between the MTHFR gene C677T and A1298C polymorphisms and the risk of URSA. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed using RevMan 5.0 and Stata 12.0 software. ResultsA total of 42 case-control studies involving 3 970 URSA patients and 5 297 controls were included. The results of meta-analysis showed that MTHFR C677T polymorphism was associated with the increased risk of URSA (T vs. C: OR=1.34, 95% CI 1.16 to1.54, P < 0.000 01; TT vs. TC+CC: OR=1.70, 95% CI 1.36 to 2.12, P < 0.000 01; TT+TC vs. CC: OR=1.34, 95% CI 1.11 to 1.62, P=0.002; TC vs. CC: OR=1.19, 95% CI 0.99 to 1.43, P=0.061; TT vs. CC: OR=1.95, 95% CI 1.48 to 2.56, P < 0.000 01). Subgroup analysis by ethnicity indicated that the MTHFR C677T polymorphism was associated with the increased risk of URSA in east Asians (T vs. C: OR=1.61, 95% CI 1.39 to 1.87, P < 0.000 01; TT vs. TC+CC: OR=2.05, 95% CI 1.54 to 2.71, P < 0.000 01; TT+TC vs. CC: OR=1.76, 95% CI 1.41 to 2.19, P < 0.000 01; TC vs. CC: OR=1.53, 95% CI 1.21 to 1.94, P < 0.000 01; TT vs. CC: OR=2.77, 95% CI 1.94 to 3.97, P < 0.000 01) but was not associated with the increased risk of URSA in Caucasians. The results of meta-analysis also showed that there was no significant association between the MTHFR A1298C polymorphism and the URSA in all population. ConclusionCurrent evidence indicates that significant association is found between MTHFR C677T mutation and URSA in east Asians but not in Caucasians. Further study indicates that women carrying TT or TC gene significantly increases the risk of URSA and TT mutant gene carriers have a higher URSA risk. There is no significant association between MTHFR A1298C mutation and URSA in all population. Due to the quantity and quality limitations of included studies, more high quality case-control or cohort studies are needed to verify the above conclusions.