MTRR gene variants may predispose to the risk of Congenital Heart Disease in Down syndrome patients of Indian origin

Background: Down syndrome [DS], also called as trisomy 21, is one of the most leading cause of intellectual disability. DS is associated with a number of phenotypes including Congenital Heart Disease [CHD], Leukemia, Alzheimer's disease, Hirschsprung's disease and others. DS affects about 1 in 700 live births

Objectives: The study aims to investigate the association of MTRR [Methionine synthase reductase] gene polymorphisms [C524T and A66G] with the risk of CHD in DS patients

Methods: PCR and PCR-RFLP methods were used for the genotyping of study samples and results were validated using Sanger's sequencing

Results: MTRR C524T and A66G were significantly associated with the increased risk of CHD in DS. We have also reported two novel polymorphisms, T19775C and 19778_19778delG, in DS with CHD cases with a frequency of 93% and 40%, respectively. These two polymorphisms were not found among DS without CHD group

Conclusion: Results from this study indicate that the MTRR C524T and A66G polymorphisms influence the risk of the occurrence of CHD in DS patients of Indian Origin. This is the first report from India highlighting the potential association of MTRR C524T and A66G polymorphisms with CHD in DS. We are also the first one to report two novel polymorphisms, T19775C and 19778_19778delG in DS with CHD group. Hence these four polymorphisms can be used to evaluate the risk of CHD in DS patients

Molecular and functional characterization of ferredoxin NADP(H) oxidoreductase from Gracilaria chilensis and its complex with ferredoxin

BACKGROUND: Ferredoxin NADP(H) oxidoreductases (EC 1.18.1.2) (FNR) are flavoenzymes present in photosynthetic organisms; they are relevant for the production of reduced donors to redox reactions, i.e. in photosynthesis, the reduction of NADP+ to NADPH using the electrons provided by Ferredoxin (Fd), a small FeS soluble protein acceptor of electrons from PSI in chloroplasts. In rhodophyta no information about this system has been reported, this work is a contribution to the molecular and functional characterization of FNR from Gracilaria chilensis, also providing a structural analysis of the complex FNR/Fd. METHODS: The biochemical and kinetic characterization of FNR was performed from the enzyme purified from phycobilisomes enriched fractions. The sequence of the gene that codifies for the enzyme, was obtained using primers designed by comparison with sequences of Synechocystis and EST from Gracilaria. 5'RACE was used to confirm the absence of a CpcD domain in FNRPBS of Gracilaria chilensis. A three dimensional model for FNR and Fd, was built by comparative modeling and a model for the complex FNR: Fd by docking. RESULTS: The kinetic analysis shows KMNADPH of 12.5 M and a kcat of 86 s-1, data consistent with the parameters determined for the enzyme purified from a soluble extract. The sequence for FNR was obtained and translated to a protein of 33646 Da. A FAD and a NADP+ binding domain were clearly identified by sequence analysis as well as a chloroplast signal sequence. Phycobilisome binding domain, present in some cyanobacteria was absent. Transcriptome analysis of Gch revealed the presence of two Fd; FdL and FdS, sharing the motif CX5CX2CX29X. The analysis indicated that the most probable partner for FNR is FdS. CONCLUSION: The interaction model produced, was consistent with functional properties reported for FNR in plants leaves, and opens the possibilities for research in other rhodophyta of commercial interest.

Geographical distribution of MTHFR and MTRR gene polymorphisms among the Han women in Zhengzhou city / 中南大学学报(医学版)

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.

Association of plasma homocysteine level and polymorphism of methione synthase reductase gene with essential hypertension in ethnic Uyghurs and Hans from Xinjiang / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association of plasma homocysteine (Hcy) level and 66A/G and 524C/T polymorphisms of methionine synthase reductase (MSR) gene with essential hypertension (EH) in ethnic Uygurs and Hans from Xinjiang.</p><p><b>METHODS</b>From September 2011 to July 2014, 199 Uyghur and 216 Han patients were collected, while 195 healthy Uyghur ethnics and 217 healthy Han ethnics were recruited as the controls. Polymerase chain reaction and restriction fragment length polymorphism (PCR-RELP) was adopted to detect the above polymorphisms. Enzyme immunological assay was applied to measure the levels of plasma Hcy.</p><p><b>RESULTS</b>Compared with the control, plasma Hcy levels were significantly higher in EH group in both Uyghur and Han ethnics (P<0.05). In both ethnic groups, there were also significant differences in MSR 524C/T polymorphism between the patients and controls (Uyghur: chi-square=6.559, P=0.038; Han: chi-square=12.684, P=0.002). No significant difference was found in MSR 66A/G polymorphism between the patients and controls in both ethnic groups (P>0.05). Plasma Hcy level in those with a 66G/524C genotype was statistically higher than that with 66A/524T (P<0.05). After adjusting confounding factors such as gender and age, Logistic regression analysis indicated that age (OR=1.924, 95% CI:1.177- 3.164, P=0.009), obesity (OR=2.491, 95% CI: 1.584-3.920, P<0.01), hyperhomocysteine (OR=1.609, 95% CI: 1.016-2.548, P=0.043) were independent risk factors for EH in Uygurs, while age (OR=1.133, 95% CI: 1.010-81.272, P=0.033), hyperhomocysteine level (OR=3.894, 95% CI: 2.432-6.237, P<0.01), and obesity (OR=1.864, 95% CI: 1.141-3.046, P=0.013) were independent risk factors for EH in Han ethnics. No association was found between the polymorphisms and EH in Uygurs and Hans.</p><p><b>CONCLUSION</b>Age, hyperhomocysteine and obesity were common independent risk factors for EH in both Uygur and Han ethnics from Xinjiang. The MSR 66G genotype can increase the plasma concentration of Hcy, while MSR 524T genotype may reduce it. MSR 524C/T TT genotype may be a protective factor for EH. MSR polymorphisms 66A/G and 524C/T are not independent risk factors for EH in Uygur and Han ethnics from Xinjiang.</p>

Association of MTHFR and MTRR genes polymorphisms with non-disjunctions of chromosomes 18 and 21 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the effect of MTHFR and MTRR genes polymorphisms on chromosomes 18 and 21 non-disjunction through investigation of Henan Han Chinese young females with a gestational history of trisomy 21 (Down syndrome, DS) or trisomy 18 (Edwards syndrome, ES).</p><p><b>METHODS</b>Polymorphisms of MTHFR 677C/T, MTHFR 1298A/C and MTRR 66A/G were analyzed in 73 healthy females (controls group), 78 females with a gestational history of DS (DS group) and 54 females with a gestational history of ES (ES group) by direct sequencing of PCR products from amplification of peripheral blood lymphocyte DNA.</p><p><b>RESULTS</b>The frequency of MTHFR 677T allele was significantly different among the DS group, ES group and the control group (P<0.05). The frequency of MTRR 66G allele was significantly different only between the DS group and the control group (P<0.05). MTHFR 1298A/C polymorphisms were not associated with either ES or DS. Compared with the wild genotype MTHFR 677CC or MTRR 66AA, carriers of the MTHFR 677CT, 677TT, or MTRR 66GG genotypes had respectively 2.694 times (95%CI: 1.204-6.025, P<0.05), 5.451 times (95%CI: 2.211-13.435, P<0.05) and 9.618 times (95%CI: 2.085-44.365, P<0.05) risk of bearing a DS baby. Compared with the wild genotype MTHFR 677CC, carriers of the MTHFR 677CT and 677TT genotype had respectively 2.701 times (95%CI: 1.133-6.438, P<0.05) and 3.804 times (95%CI: 1.406-10.293, P<0.05) risk of bearing a ES baby. Neither MTRR 66AG or 66GG genotype was associated with the occurrence of ES.</p><p><b>CONCLUSION</b>The MTHFR 677T and MTRR 66G may represent a risk factor for DS gestation, while MTHFR 677T may represent a risk factor for ES gestation for Chinese Han females.</p>

An association study between gene polymorphism of the key enzyme's folacin metabolism pathway and plasmatic homocysteine levels in fertile woman / 中华预防医学杂志

<p><b>OBJECTIVE</b>The effect of the gene polymorphism for the key enzyme's folacin metabolism pathway on plasmatic homocysteine (Hcy) levels in fertile woman was observed.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>Eight 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.</p><p><b>CONCLUSION</b>The gene mutations of two SNP sites rs1801131 and rs1801133 in MTHFR would increase Hcy levels.</p>

Association of folate metabolism genes MTRR and MTHFR with complex congenital abnormalities among Chinese population in Shanxi Province, China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>A 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).</p><p><b>RESULTS</b>SNPs 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.</p><p><b>CONCLUSIONS</b>Among 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.</p>

Analysis of methionine synthase reductase polymorphism (A66G) in Indian Muslim population.

BACKGROUND AND OBJECTIVES: Methionine synthase reductase (MTRR) is a vital enzyme of homocysteine/methionine metabolic pathway and is required for the conversion of inactive form of methionine synthase (MTR) to its active form. A clinically important allelic variant of MTRR A66G, with less enzymatic activity is reported with worldwide prevalence rate of ~ 30%. The present study was designed to determine the frequency of MTRR A66G polymorphism in rural Sunni Muslim population of Eastern Uttar Pradesh. MATERIALS AND METHODS: Total 56 subjects were analyzed for MTRR A66G polymorphism. A66G mutation analysis was carried out according to the polymerase chain reaction-restriction fragment length polymorphism method of Wilson et al. [1] amplification with MTRR specific primers followed by amplicon digestion with NdeI enzyme was used for the identification of different MTRR genotypes in subjects. RESULTS AND DISCUSSION: The AA genotype was found in 5 subjects, AG in 23 subjects, and GG genotype in 28 subjects. Genotype frequencies of AA, AG, and GG were 0.089, 0.41, and 0.5 respectively. The allele frequency of A allele was found to be 0.298 and G allele was 0.705. CONCLUSION: It is evident from the present study that the percentage of homozygous genotype GG and frequency of G allele is high in the target Muslim population.

Methylenetetrahydrofolate reductase and methionine synthase reductase gene polymorphisms in ethnic Han women from Linyi / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To 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).</p><p><b>METHODS</b>A 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.</p><p><b>RESULTS</b>(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).</p><p><b>CONCLUSION</b>MTHFR 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.</p>

Polymorphisms of homocysteine metabolism enzyme-related genes MS and MSR in Buyi, Dong and Miao ethnics from Guizhou / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate polymorphisms of homocysteine metabolism enzyme-related genes methionine synthase (MS) and methionine synthase reductase (MSR) in Buyi, Dong, Miao ethnics from Guizhou.</p><p><b>METHODS</b>Genotypes of MS and MSR genes of healthy individuals from the three ethnic groups were determined with a TaqMan-MGB probe genotyping method and compared.</p><p><b>RESULTS</b>For 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).</p><p><b>CONCLUSION</b>The distributions of MS gene A2756G and MSR gene A66G polymorphisms have differed significantly between the three ethnic groups and individuals from various regions.</p>

Association Study between Folate Pathway Gene Single Nucleotide Polymorphisms and Gastric Cancer in Koreans

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.

Genetic variation in genes involved in folate and drug metabolism in a south Indian population.

BACKGROUND: Genetic variations represented as single nucleotide polymorphisms (SNPs) vary across the world population. This genetic polymorphism (such as SNPs) plays an important role in pharmacogenomics. SNPs that affects cellular metabolism, by altering the enzyme activity, have an important role in therapeutic outcome. Allele frequencies in number of clinically relevant SNPs within south Indian populations are not yet known. Hence, we genotyped randomly selected unrelated south Indian subjects from different locations of south India representing the heterogeneous ethnic background of the population. MATERIALS AND METHODS: Common variants of MTHFD1, TYMS, SHMT1, MTR, MTRR, CBS and SULT1A1 gene polymorphisms were screened from healthy unrelated south Indian volunteers. Genotypes were determined using RFLP analysis of polymerase chain reaction-amplified products and confirmed by DNA sequencing. Chi-square test was performed to test for deviation from the Hardy-Weinberg equilibrium for each locus. RESULTS: Gene allele frequency for several polymorphisms in our study differed significantly between the populations of other nations reported for several of the SNPs. These results demonstrate that the populations in different geographic regions may have widely varying genetic allele frequencies for clinically relevant SNPs. CONCLUSION: The present study reports, for the first time, the frequency distribution of MTHFD1, TYMS, SHMT1, MTR, MTRR, CBS and SULTIA1 gene polymorphisms in a south Indian population. Population-specific genetic polymorphism studies will help in practicing pharmacogenomic principles in the clinics.

Associations of polymorphisms of methionine synthase A2756G and methionine synthase reductase G66A with the risks of coronary artery disease: a meta-analysis / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate the associations between polymorphisms of methionine synthase(MTR) A2756G and methionine synthase reductase(MTRR) G66A and risk of coronary artery disease.</p><p><b>METHODS</b>Literatures 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.</p><p><b>RESULTS</b>Among 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.</p><p><b>CONCLUSION</b>These 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.</p>

Genetic polymorphisms involved in folate metabolism and elevated plasma concentrations of homocysteine: maternal risk factors for Down syndrome in Brazil

The aim of the present study was to investigate the effect of polymorphisms C677T and A1298C in the methylenetetrahydrofolate reductase (MTHFR) gene, A2756G in methionine synthase reductase (MTR) gene and A80G in reduced folate carrier 1 (RFC1) gene, and plasma homocysteine (Hcy), on the maternal risk for Down syndrome (DS). Seventy-two DS mothers and 194 mothers who had no children with DS were evaluated. The investigation of the MTHFR C677T, MTR A2756G and RFC1 A80G polymorphisms was performed by polymerase chain reaction and enzyme digestion and the MTHFR A1298C polymorphism by allele-specific polymerase chain reaction. Hcy quantification was carried out by liquid chromatography-tandem mass spectrometry. The median number of polymorphic alleles for the four loci tested was greater in DS mothers compared to the control group, and the presence of three or more polymorphic alleles increased the risk for having a child with DS 1.74 times. Elevated maternal risk for DS was also observed when plasma Hcy three or more polymorphic alleles for MTHFR C677T, MTHFR A1298C, MTR A2756G, and RFC1 A80G, and plasma Hcy concentrations higher than 4.99 mi mol/L are maternal risk factors for DS.

Combined impact of polymorphism of folate metabolism genes; glutamate carboxypeptidase, methylene tetrahydrofolate reductase and methionine synthase reductase on breast cancer susceptibility in Kashmiri women

Folate and methionine play a crucial role in DNA synthesis, repair and the epigenetic profile of cell. Hence, the alterations in the folate metabolism can lead to aberrant proliferation leading to neoplasia. Most of the studies have associated polymorphisms in methylene tetrahydrofolate reductase [MTHFR] and methionine synthase reductase [MTRR] genes with reduced risk of cervical and colorectal cancer. However, the association with breast cancer is still controversial. Further, the ivolvement of Glutamate carboxypeptidase II [GCPII] polymorphism in cancer is not known. In the present study, we analyzed if the individual and combined effects of polymorphisms in folate pathway genes viz., MTHFR 677C> T, MTHFR 1298A> C, MTRR 66A> G and GCP II 1561 C>T, have any role in altering the susceptibility to breast cancer. The DNA of 35 female breast cancer patients and 33 healthy individuals, in the Kashmiri population from India, were analyzed using a PCR-RFLP approach for the above mentioned polymorphisms. Individuals carrying the MTHFR 677CT/TT and GCPII 1561 CT genotype showed a 3.5 [95% CI: 3.1-3.7, P<0.02] and 7.7 [95% CI: 6.7-9.1, P<0.001] fold decreased risk for breast cancer than the wild types [MTHFR 677CC and GCPII 1561 CC]. Subjects with MTRR 66 G-allele showed a 4.5 fold decreased risk [OR: 0.22, 95% CI: 0.20, 0.24, P<0.0005] compared to the wild type [MTRR 66A]. Further, subjects with combined polymorphisms in MTHFR, GCPII and MTRR loci revealed a significant reduction of breast cancer risk. This study indicates [i] a protective role of polymorphisms in MTHFR, GCPII, MTRR against breast cancer in the study subjects, and [ii] combined effect of polymorphisms is more pronounced than single genetic polymorphism, thereby emphasizing the role of gene-gene interaction in the susceptibility to breast cancer

Polymorphisms of 5, 10-Methylentetrahydrofolate Reductase (MTHFR C677T) and Methionine Synthase Reductase (MTRR A66G) as Maternal Risk Factors for Fetal Aneuploidy

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.

Polymorphisms in genes involved in folate metabolism as maternal risk factors for Down syndrome in China / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Genomic 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.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>MTHFR and MTRR gene mutation alleles are related to Down syndrome, and CT, TT and GG gene mutation types increase the risk of Down syndrome.</p>

Polymorphisms in genes MTHFR, MTR and MTRR are not risk factors for cleft lip/palate in South Brazil

Non-syndromic cleft lip and palate (CL/P) occurs due to interaction between genetic and environmental factors. Abnormalities in homocysteine metabolism may play a role in its etiology due to polymorphisms in genes involved in this pathway. Because of the involvement of MTHFR, MTR and MTRR genes with folate metabolism and the evidence that maternal use of folic acid in early pregnancy reduces the risk for CL/P, we evaluated the influence of their polymorphisms on the etiology of CL/P through a case-control study. The analyses involved 114 non-syndromic phenotypically white children with clefts (case) and 110 mothers, and 100 non-affected (control) children and their mothers. The polymorphisms 677C>T of MTHFR, 2756A>G of MTR, and 66A>G of MTRR genes were analyzed by PCR-RFLP. Allelic frequencies did not differ from other studies conducted on white populations for MTHFR 677T allele (0.35) and for MTR 2756G allele (0.17), but MTRR 66G allele frequency (0.35) was lower than observed elsewhere. The genotypic distribution of the 677C>T polymorphisms under study did not show significant differences between CL/P patients, their mothers and controls. These results suggest that the alterations of folate metabolism related to these polymorphisms are not involved in clefting in the population under study.

Methionine synthase reductase polymorphisms are associated with serum osteocalcin levels in postmenopausal women

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.

Association between genetic polymorphisms in folate metabolic enzyme genes and colorectal cancer: a nested case-control study / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the interrelationship of genetic polymorphisms in folate metabolic enzymes (MTHFRC677T, MTHFRA1298C, MTRA2756G and MTRRA66G) and their combinative effects with colorectal cancer (CRC).</p><p><b>METHODS</b>A nested case-control study was designed and carried out. 140 CRC patients and 343 control subjects were included in this study. Polymorphisms of folate metabolic enzyme genes were genotyped by PCR-restriction fragment length polymorphism method. Risk of CRC was estimated by unconditional logistic model, and P value for interaction was calculated by likelihood test.</p><p><b>RESULTS</b>The allele of MTR2756G showed a positive association with CRC (OR = 2.04, 95% CI = 1.22 - 3.40). Those with MTHFR1298AA and MTR 2756AG/GG genotypes had an elevated risk with CRC (OR = 2.57, 95% CI, 1.42 -4.65), and their combinative effect showed a significant association with CRC (P = 0.04).</p><p><b>CONCLUSION</b>MTR2756G allele may be a risk factor of CRC, and interaction may exsit between polymorphisms of MTHFRA1298C and MTRA2756G. Further studies with larger sample and in different ethnic groups are needed.</p>