OBJECTIVETo evaluate the associations between polymorphisms of methionine synthase(MTR) A2756G and methionine synthase reductase(MTRR) G66A and risk of coronary artery disease.

METHODSLiteratures in Medline reporting the relationship between polymorphisms of MTR A2756G and MTRR G66A and risk of coronary artery disease from January 1990 to May 2010 were searched. A total of 14 relevant articles were selected and 13 of them met the criteria. A Meta-analysis was performed to estimate the pooled odds ratio (OR) to evaluate the relationship between polymorphisms of MTR A2756G and MTRR G66A and risk of coronary artery disease. All analyses were performed using the STATA statistical software.

RESULTSAmong the 13 studies, eight case-control studies containing 2143 cases of coronary artery disease and 2270 controls were included in the analysis of MTR A2756G and risk of coronary artery disease. Meanwhile, five case-control studies with 811 cases of coronary artery disease and 387 controls were included in the analysis of MTRR G66A and risk of coronary artery disease. In the analysis of MTRR G66A related to the risk of coronary artery disease, there were 246 GG carries, 397 AG carriers and 168 AA carriers in the group of coronary artery disease, against 102 GG carriers, 203 AG carriers and 82 AA carriers in the control group. Compared with the MTRR GG carriers, the risk of coronary artery disease decreased significantly by 27% (OR = 0.73, 95%CI: 0.54 - 0.99) and 25% (OR = 0.75, 95%CI: 0.56 - 1.00) (Egger's test t = -0.19, P = 0.862) in the MTRR 66 AG and AG/AA carriers, respectively, and also decreased in the MTRR AA carriers but significant difference was observed (OR = 0.84, 95%CI: 0.42 - 1.68). There was no significant association between coronary artery disease and MTR A2756G.

CONCLUSIONThese results suggest that MTRR66 may play a role in coronary artery disease susceptibility. MTRR 66 A allele carries are associated with a statistically significant decreased risk of coronary artery disease susceptibility.

5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase ; genetics ; Alleles ; Coronary Artery Disease ; genetics ; Ferredoxin-NADP Reductase ; genetics ; Genetic Predisposition to Disease ; Genotype ; Humans

Gastric cancer is ranked as the most common cancer in Koreans. A recent molecular biological study about the folate pathway gene revealed the correlation with a couple of cancer types. In the folate pathway, several genes are involved, including methylenetetrahydrofolate reductase (MTHFR), methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR), and methyltetrahydrofolate-homocysteine methyltransferase (MTR). The MTHFR gene has been reported several times for the correlation with gastric cancer risk. However, the association of the MTRR or MTR gene has not been reported to date. In this study, we investigated the association between the single nucleotide polymorphisms (SNPs) of the MTHFR, MTRR, and MTR genes and the risk of gastric cancer in Koreans. To identify the genetic association with gastric cancer, we selected 17 SNPs sites in folate pathway-associated genes of MTHFR, MTR, and MTRR and tested in 1,261 gastric cancer patients and 375 healthy controls. By genotype analysis, estimating odds ratios and 95% confidence intervals (CI), rs1801394 in the MTRR gene showed increased risk for gastric cacner, with statistical significance both in the codominant model (odds ratio [OR], 1.39; 95% CI, 1.04 to 1.85) and dominant model (OR, 1.34; 95% CI, 1.02 to 1.75). Especially, in the obese group (body mass index > or = 25 kg/m2), the codominant (OR, 9.08; 95% CI, 1.01 to 94.59) and recessive model (OR, 3.72; 95% CI, 0.92 to 16.59) showed dramatically increased risk (p < 0.05). In conclusion, rs1801394 in the MTRR gene is associated with gastric cancer risk, and its functional significance need to be validated.
5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase ; Ferredoxin-NADP Reductase ; Folic Acid ; Genotype ; Humans ; Methylenetetrahydrofolate Reductase (NADPH2) ; Odds Ratio ; Oxidoreductases ; Polymorphism, Single Nucleotide ; Stomach Neoplasms

OBJECTIVETo explore the association of polymorphisms in folate metabolism genes, methionine synthase reductase (MTRR) gene and 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, with complex congenital abnormalities and to further investigate its association with complex congenital abnormalities derived from three germ layers.

METHODSA total of 250 cases of birth defects (with complex congenital abnormalities including congenital heart disease, neural tube defects, and craniofacial anomalies) in Shanxi Province, China were included in the study. MTRR single nucleotide polymorphism (SNP) (rs1801394) and MTHFR SNP (rs1801133) were genotyped by the SNaPshot method, and the genotyping results were compared with those of controls (n=420).

RESULTSSNPs rs1801394 and rs1801133 were associated with multiple birth defects. For the recessive model, individuals with GG genotype at rs1801394 and CC genotype at rs1801133 had a relatively low risk of developing birth defects, so the two genotypes were protective factors against birth defects. The homozygous recessive genotype at rs1801133, which served as a protective factor, was associated with ectoderm- or endoderm-derived complex congenital abnormalities, while the homozygous recessive genotype at rs1801394, which served as a protective factor, was associated with ectoderm-, mesoderm- or endoderm-derived complex congenital abnormalities.

CONCLUSIONSAmong the Chinese population in Shanxi Province, the SNPs in folate metabolism genes (MTRR and MTHFR) are associated with complex congenital abnormalities and related to ectoderm, mesoderm or endoderm development.

Asian Continental Ancestry Group ; genetics ; China ; Congenital Abnormalities ; genetics ; Ferredoxin-NADP Reductase ; genetics ; Genotype ; Germ Layers ; embryology ; Humans ; Methylenetetrahydrofolate Reductase (NADPH2) ; genetics ; Polymorphism, Single Nucleotide

OBJECTIVE: To explore the genotype distribution of 5,10-methylenetetrahydrofolate reductase (MTHFR) and 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) among Chinese Han women in Zhengzhou. 
 METHODS: A total of 1 253 women were recruited from Zhengzhou city. The genotype of MTHFR C677T, A1298C and MTRR A66G was detected to analyze the distribution of gene polymorphisms and to compare them with the published data from other Han women.
 RESULTS: The frequency of the MTHFR 1298CC genotypes (1.3%) in Zhengzhou was lower than that in Xiangtan (4.8%), Yanbian (3.8%), Zhenjiang (3.5%), Jingzhou (3.2%), Kunming (2.7%), Deyang (6.3%), Huizhou (7.2%) and Wulumuqi (3.4%) (all P<0.05). The difference in allele frequency was significant compared with that in Yantai, Yanbian, Wulumuqi, Zhenjiang, Jingzhou, Kunming, Dezhou, Xiangtan or Huizhou (all P<0.05). The frequency of the MTRR 66GG genotypes (5.4%) in Zhengzhou was lower than that in Deyang (8.2%) (P<0.01) and allele frequency between them was significant difference (P<0.05). 
 CONCLUSION The gene polymorphism of MTHFR A1298C and MTRR A66G among the Han women in Zhengzhou is statistically different from that in some regions of China.
Alleles ; Asian Continental Ancestry Group ; genetics ; China ; Female ; Ferredoxin-NADP Reductase ; genetics ; Gene Frequency ; Genotype ; Humans ; Methylenetetrahydrofolate Reductase (NADPH2) ; genetics ; Polymorphism, Genetic

Homocysteine (Hcy) is thought to play an important role in the development of osteoporosis and fracture. Methionine synthase reductase (MTRR) is an enzyme involved in the conversion of Hcy to methionine. We hypothesized that certain genetic polymorphisms of MTRR leading to reduced enzyme activity may cause hyperhomocysteinemia and affect bone metabolism. We therefore examined the associations of the A66G and C524T polymorphisms of the MTRR gene with bone mineral density (BMD) and serum osteocalcin levels in postmenopausal women. Although we did not detect any significant associations between MTRR polymorphisms and BMD or serum osteocalcin levels, we found that the 66G/524C haplotype, which has reduced enzyme activity, was significantly associated with serum osteocalcin levels in a gene-dose dependent manner (P=0.002). That is, the highest osteocalcin levels (34.5+/-16.8 ng/ml) were observed in subjects bearing two copies, intermediate osteocalcin levels (32.6+/-14.4 ng/ml) were observed in subjects bearing one copy, and the lowest levels of osteocalcin (28.8+/-10.9 ng/ml) were observed in subjects bearing no copies. These results suggest that the 66G/524C haplotype of the MTRR gene affect bone turn over rate.
Postmenopause/*blood ; *Polymorphism, Genetic ; Osteocalcin/*blood ; Middle Aged ; Lumbosacral Region/radiography ; Humans ; Genotype ; Ferredoxin-NADP Reductase/*genetics/physiology ; Femur Neck/radiography ; Female ; Bone Density ; Aged, 80 and over ; Aged

OBJECTIVEThe effect of the gene polymorphism for the key enzyme's folacin metabolism pathway on plasmatic homocysteine (Hcy) levels in fertile woman was observed.

METHODSThe subjects were from Shaoxing City, Jiangsu province in 2012, the selection criteria for the women of childbearing age were between 20-45 years old, with an average age of 28.2 (95%CI:27.8-28.6) years old. Sample collection continued uninterrupted lasted seven days, a total of 535 samples were collected, venous blood with EDTA addition or sodium citrate to anticoagulant. After separation, the blood cells and blood plasma were cryopreserved. DNA was extracted using spin column method. All the samples were selected for the gene polymorphism testing of the key enzyme's on folate metabolism and monitoring of plasmatic Hcy level.

RESULTSEight single nucleotide polymorphism (SNP) sites of methylenetetrahydrofolate reductase gene (MTHFR) , methionine synthase gene (MS) , synthetic methionine reductase gene (MSR) and cystathionine β synthase gene (CBS) were detected. It was found the genotype AA of the SNP sites-rs1801131 would result higher plasmatic Hcy levels (8.99 µmol/L) than the genotypes CC (7.81 µmol/L) and CA(8.38 µmol/L) (P < 0.01) . Similarly, the genotype TT of the SNP sites-rs1801133 was significantly responded to the increasing of Hcy levels (11.10 µmol/L) than the genotype CC (8.15 µmol/L) and CT (8.45 µmol/L), (P < 0.01) . The two sites of genotype combination of AA-TT could also result in the significant increase of Hcy levels (11.02 µmol/L) than other combined genotypes (genotypes CC-CC, CA-CC, CA-CT, AA-CC, AA-CT), especially the genotype CC-CC. And the risk factor was 1.41 (95CI:1.20-1.66) times over the genotype CC-CC.

CONCLUSIONThe gene mutations of two SNP sites rs1801131 and rs1801133 in MTHFR would increase Hcy levels.

5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase ; genetics ; Adult ; China ; Cystathionine beta-Synthase ; genetics ; Female ; Ferredoxin-NADP Reductase ; genetics ; Folic Acid ; Genotype ; Homocysteine ; blood ; genetics ; Humans ; Methylenetetrahydrofolate Reductase (NADPH2) ; genetics ; Mutation ; physiology ; Polymorphism, Single Nucleotide ; Risk Factors

OBJECTIVETo explore the distribution of genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) 677C/T, 1298A/C and methionine synthase reductase (MTRR) 66A/G among ethnic Han females from Linyi, and to correlate it with serum level of homocysteine (Hcy).

METHODSA cross-sectional study was carried out. Oral epithelial cell samples were collected from 825 subjects. MTHFR and MTRR gene polymorphisms were determined with a Taqman-Minor Groove Binder (MGB) method. Distribution of gene polymorphisms was analyzed and compared with others regions of China including Weifang, Zhengzhou, Deyang and Hainan. A biochemical assay was also carried out to determine the total Hcy in plasma of 281 subjects. The reductase activity of MTHFR was classified into decreased and stable groups according to genetic polymorphism of MTHFR. Correlation between MTHFR groups and total Hcy level were also explored.

RESULTS(1) The frequencies of MTHFR677CC, CT and TT genotypes of the selected subjects were 16.7%, 48.3% and 35.0%, respectively. The frequencies of MTHFR 1298AA, AC and CC genotypes were 76.0%, 21.6% and 2.4%, respectively. And those of MTRR 66AA, AG and GG genotypes were 54.7%, 39.4% and 5.9%, respectively. For the selected subjects, their frequency of MTHFR 677TT genotype was higher than that of Deyang and Hainan (P< 0.01), whilst the frequency of MTHFR 1298CC genotype was lower than that of Deyang and Hainan (P < 0.01), and the frequency of MTRR 66 GG genotype was lower than that of Hainan (P< 0.01). (2) The Hcy level for those with decreased MTHFR activity was significantly higher than those with stable MTHFR activity (P< 0.05).

CONCLUSIONMTHFR gene 677C/T, 1298A/C and MTRR 66A/G polymorphisms in ethnic Han women from Linyi have differed significantly from other regions of China. Decreased MTHFR activity caused by genetic polymorphisms is a risk factor for raised Hcy level.

Adult ; Alleles ; Asian Continental Ancestry Group ; genetics ; China ; Female ; Ferredoxin-NADP Reductase ; genetics ; Gene Frequency ; Genetic Association Studies ; Genotype ; Homocysteine ; blood ; Humans ; Methylenetetrahydrofolate Reductase (NADPH2) ; blood ; genetics ; Polymorphism, Single Nucleotide ; Young Adult

OBJECTIVETo explore the relationship between genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), the central enzymes in folate metabolism that affects DNA methylation and synthesis, and the risk of Down syndrome in China.

METHODSGenomic DNA was isolated from the peripheral lymphocytes of 64 mothers of children with Down syndrome and 70 age matched control subjects. Polymerase chain reaction and restriction fragment length polymorphism were used to examine the polymorphisms of MTHFR 677C-->T, MTRR 66A-->G and the relationship between these genotypes and the risk of Down syndrome was analyzed.

RESULTSThe results show that the MTHFR 677C-->T polymorphism is more prevalent among mothers of children with Down syndrome than among control mothers, with an odds ratio of 3.78 (95% confidence interval (CI), 1.78 approximately 8.47). In addition, the homozygous MTRR 66A-->G polymorphism was independently associated with a 5.2-fold increase in estimated risk (95% CI, 1.90 approximately 14.22). The combined presence of both polymorphisms was associated with a greater risk of Down syndrome than the presence of either alone, with an odds ratio of 6.0 (95% CI, 2.058 approximately 17.496). The two polymorphisms appear to act without a multiplicative interaction.

CONCLUSIONMTHFR and MTRR gene mutation alleles are related to Down syndrome, and CT, TT and GG gene mutation types increase the risk of Down syndrome.

Alleles ; Case-Control Studies ; China ; Down Syndrome ; diagnosis ; ethnology ; genetics ; Female ; Ferredoxin-NADP Reductase ; genetics ; Folic Acid ; metabolism ; Genetic Predisposition to Disease ; Genotype ; Homozygote ; Humans ; Lymphocytes ; metabolism ; Methylenetetrahydrofolate Reductase (NADPH2) ; genetics ; Polymorphism, Genetic ; Risk Factors

PURPOSE: Aneuploidy is the cause of diseases such as Down syndrome or Edward syndrome and, more generally, is a major cause of mental retardation and fetal loss. The purpose of this study was to evaluate the association between MTHFR (C677T) or MTRR (A66G) polymorphisms and fetal aneuploidy. MATERIALS AND METHODS: Data was collected from 37 women who had a fetus with aneuploidy (cases) and 78 women who had previously delivered at least two healthy children without aneuploidy and did not have a history of miscarriage or abnormal pregnancy (controls). The MTHFR (C677T) or MTRR (A66G) polymorphisms were analyzed by PCR-restriction fragment length polymorphism assay. RESULTS: The frequencies of the MTHFR 677 CC, CT, and TT genotypes were 30.7%, 48.7%, and 20.6% in the control group and 37.8%, 48.6%, and 13.5% in the case group, respectively. There were no significant differences in genotype frequencies between the two groups. For the MTRR A66G polymorphism, the frequencies of the AA, AG and GG genotypes were 50%, 46.1%, and 3.9% in the control group and 13.5%, 81.1%, and 5.4% in case group, respectively. The frequency of the MTRR AG mutant was significantly increased in the case group, with an odds ratio of 6.5 (95% CI: 2.3-18.6, P<0.05). CONCLUSION: The results of this study suggest that mother carriers with the MTRR G allele have an increased risk of fetal aneuploidy, while the MTHFR T allele is not associated with increased risk of fetal aneuploidy. The MTRR A66G polymorphism may be a risk factor for producing a child with chromosomal aneuploidy.
5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase ; Abortion, Spontaneous ; Alleles ; Aneuploidy ; Child ; Down Syndrome ; Female ; Ferredoxin-NADP Reductase ; Fetus ; Genotype ; Humans ; Intellectual Disability ; Methionine ; Mothers ; Odds Ratio ; Oxidoreductases ; Pregnancy ; Risk Factors

OBJECTIVETo investigate polymorphisms of homocysteine metabolism enzyme-related genes methionine synthase (MS) and methionine synthase reductase (MSR) in Buyi, Dong, Miao ethnics from Guizhou.

METHODSGenotypes of MS and MSR genes of healthy individuals from the three ethnic groups were determined with a TaqMan-MGB probe genotyping method and compared.

RESULTSFor Buyi, Dong and Miao ethnics from Guizhou, frequencies of MS gene 2756G allele were respectively 12.0%, 8.9% and 15.4%. However, no significant difference was found by statistics. Frequencies of MS A2756G alleles for the three ethnic groups are similar to those of Han Chinese from Beijing and Henan, Hui ethnics from Ningxia as well as European populations, but differ significantly from those of Japanese, Indians, Africans and Nigerians (P < 0.05). Frequencies of MSR gene 66 G allele were respectively 32.3%, 30.4% and 21.2% for Buyi, Dong and Miao ethnics. Miao is significantly lower than Buyi and Dong (P< 0.05). Frequencies of MSR gene A66G alleles for the three ethnic groups are similar to those of Han Chinese from Beijing and Guangdong, Japanese, Africans and Nigerians populations, but differ significantly from those of Indians and European (P< 0.05).

CONCLUSIONThe distributions of MS gene A2756G and MSR gene A66G polymorphisms have differed significantly between the three ethnic groups and individuals from various regions.

5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase ; genetics ; Adult ; Alleles ; Asian Continental Ancestry Group ; genetics ; China ; ethnology ; Ethnic Groups ; genetics ; Female ; Ferredoxin-NADP Reductase ; genetics ; Gene Frequency ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide