|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
MTHFR C677T, but not A1298C, was associated with neural tube defects (OR, 1.24; 95% CI, 1.08-1.42) and Down syndrome (OR, 1.65; 95% CI, 1.39-1.95).
|
30474229 |
2019 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
Polymorphisms in certain folate-Hcy-pathway genes (especially the T allele of MTHFR C677T), elevated Hcy and poor folate levels in mothers during pregnancy have been shown to be risk factors for Down syndrome in certain Asian populations (including the eastern region of India), while the same SNPs are not a risk factor in European populations.
|
26040482 |
2015 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
However, when gene-gene interactions between these two polymorphisms together with previous studied C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene were analyzed, the combined MTHFR 677CT/TT and MTHFD 1958AA/GA genotype was found to be significantly associated with the risk of having a Down syndrome child [odds ratio (OR) = 3.11; 95% confidence interval (95%CI) = 1.07-9.02].
|
24668664 |
2014 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
Overall analysis suggests an association of the MTHFR C677T polymorphism with maternal risk for DS.
|
24913031 |
2014 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
The pooled OR was estimated under five genetic models and significant association was found between maternal MTHFR 677C>T polymorphism and Down syndrome under four genetic models except recessive model (for T vs. C, OR = 1.26, 95% CI = 1.09-1.46, p = 0.001; for TT vs. CC, OR = 1.49, 95% CI = 1.13-1.97, p = 0.008; for CT vs. CC, OR = 1.29, 95% CI = 1.10-1.51, p = 0.001; for TT+CT vs. CC, OR = 1.35, 95% CI = 1.13-1.60, p = 0.0008; for TT vs. CT+CC, OR = 0.76, 95% CI = 0.60-0.94, p = 0.01).
|
25265565 |
2014 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
This meta-analysis supports the idea that MTHFR C677T genotype is associated with increased risk for DS offspring.
|
23295071 |
2013 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
In conclusion, MTHFR 677C > T polymorphism is a moderate risk factor for DS for some populations, and populations located in Sub-Tropical region seem to be at greater risk.
|
23184006 |
2013 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
Therefore, we carried out a meta-analysis of 26, 17, 9, 15, 9 and 6 case-control studies on the relationship between maternal methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, methionine synthase reductase (MTRR) A66G, reduced folate carrier 1 A80G and cystathionine β-synthase 844ins68 polymorphisms and the risk of having a DS offspring.
|
24068460 |
2013 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
The frequency of MTHFR C677T allele in all DS mothers was 3.2-fold higher than in the controls (odds ratio [OR] = 3.12, 95% confidence interval [CI]: 1.303-7.677).
|
21198396 |
2011 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
Understanding the biochemical structure and function of the methylenetetrahydrofolate reductase gene (MTHFR) provides new evidence in elucidating the risk of having a child with Down syndrome (DS) in association with two common MTHFR polymorphisms, C677T and A1298C.
|
20592453 |
2010 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
This study aimed to analyze a dataset of genetic and cytogenetic data in an Italian group of MDS and mothers of healthy children (control mothers) to assess the predictive capacity of artificial neural networks assembled in TWIST system in distinguish consistently these two different conditions and to identify the variables expressing the maximal amount of relevant information to the condition of being mother of a DS child.The dataset consisted of the following variables: the frequency of chromosome damage in peripheral lymphocytes (BNMN frequency) and the genotype for 7 common polymorphisms in folate metabolic genes (MTHFR 677C>T and 1298A>C, MTRR 66A>G, MTR 2756A>G, RFC1 80G>A and TYMS 28bp repeats and 1494 6bp deletion).
|
20868477 |
2010 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
We conclude that the common MTHFR 677C>T polymorphism is not likely to be a maternal risk factor for DS in our cohort and that the difference to previous studies can probably be explained by small sample size or geographic variation in gene polymorphisms involving gene-nutritional or gene-gene or gene-nutritional-environmental factors.
|
20075510 |
2009 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
Evaluation of C677T and A1298C polymorphisms of the MTHFR gene as maternal risk factors for Down syndrome and congenital heart defects.
|
19725133 |
2009 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
With the purpose of evaluating this relationship, we compared the frequencies of 677C>T and 1298A>C polymorphisms in the methylenetetrahydrofolate reductase gene (MTHFR) and 66A>G in the methionine synthase reductase gene (MTRR) between 103 young mothers of Down syndrome (DS) individuals and 108 control mothers, whose offspring was karyotypically normal, correlating it with an estimative of folate and - related micronutrients levels intake.
|
19096127 |
2008 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
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).
|
18273817 |
2008 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
The authors have conducted a study to test whether 677C-->T and/or 1298A-->C polymorphisms of MTHFR would play an additional role in susceptibility of acute myeloid leukemia (AML) in DS children.
|
19065440 |
2008 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
The present study aimed at evaluation of MTHFR 677C/T and 1298A/C polymorphisms in the MTHFR gene as maternal risk factors for DS.
|
18057532 |
2008 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
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).
|
18257130 |
2008 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
A meta-analysis of 11 case-control studies relating MTHFR C677T, MTHFR A1298C and MTRR A66G gene polymorphisms to the maternal risk of DS was carried out.
|
17934692 |
2007 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
The aim of the present study was to evaluate chromosome damage, measured by means of the micronucleus assay, in peripheral lymphocytes of a group of women (n = 34) who had a DS child in young age (<35 years) and in a control group (n = 35), and to correlate them with MTHFR 677C > T and 1298A > C, RFC-1 80G > A and MTR 2756A > G polymorphisms.
|
17702010 |
2007 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
Present results seem to indicate that none of the RFC-1 80G>A, MTHFR 677C>T, and MTHFR 1298A>C polymorphisms is an independent risk factor for a DS offspring at a young maternal age; however, a role for the combined MTHFR/RFC-1 genotypes in the risk of DS pregnancies among young Italian women cannot be excluded.
|
16596679 |
2006 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
This study was aimed at analyzing the effect of mutations in three non-synonymous SNP genes (677C > T and 1298A > C of the methylenetetrahydrofolate reductase (MTHFR) gene, and 66A > G in the MTRR gene) on total plasmatic homocysteine (Hcy), in 91 mothers of Down syndrome (DS) infants and 90 control mothers.
|
16575899 |
2006 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
(Am J Med Genet 103:128-132, 2001) found the homozygous 677T allele of the methylenetetrahydrofolate (MTHFR) gene 677C-->T polymorphism in a mother and her child with DS and cervical meningomyelocele.
|
16602006 |
2006 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
Significant association with both of these SNPs were detected, more specifically, in the mothers of DS children homozygous for the polymorphic alleles 677 T and 1298 C. The relative risk of T (C677T) and C (A1298C) homozygosity in mothers for DS-affected pregnancy was 7 (OR 7.67, 95% CI 1.67-35.08, P=0.003) and 4 (OR 4.40, 95% CI 1.45-13.26, P=0.008), respectively.
|
16489479 |
2006 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
In the present study, we determined polymorphisms of MTHFR A222V (677C > T), MTHFR E429A (1298A > C), MTRR I22M (66A > G), MTR D919G (2756A > G), and CBS 844ins68 and total plasma homocysteine levels (tHcy) among 154 mothers of children with Down syndrome (DS) and 158 control mothers from Brazil.
|
15889417 |
2005 |