|
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 |
C677T mutation in the 5,10-MTHFR gene and risk of Down syndrome in Italy.
|
12080391 |
2002 |
|
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 |
Contradictory findings have been recently published on the evaluation of genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR 677 C-->T) and methionine synthase reductase (MTRR 66 A-->G) as risk factors for having a child with Down syndrome (DS); however, the influence of polymorphisms of methionine synthase (MTR 2756 A-->G) and of MTHFR 1298 A-->C has never been evaluated.
|
12923861 |
2003 |
|
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 |
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 |
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 |
In contrast, MTHFR 677 C --> T has no influence on DS risk in France and Sicily, while homocysteine and MTR 2756 AG/GG genotypes are predictors of DS risk in Sicily.
|
14656028 |
2003 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
In the present report, we asked whether variation at MTHFR (677C-->T) or MTRR (66A-->G) might be associated with human trisomies other than trisomy 21.
|
11443546 |
2001 |
|
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 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
Mothers with the 677C-->T mutation had a 2.6-fold higher risk of having a child with Down syndrome than did mothers without the T substitution (odds ratio: 2.6; 95% CI: 1.2, 5.8; P < 0.03).
|
10500018 |
1999 |
|
Down Syndrome
|
|
0.100 |
GeneticVariation
|
BEFREE |
MTHFR C677T genotype frequencies were not significantly altered in mothers of children with Down syndrome (P = 0.74).
|
11807890 |
2002 |
|
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 |
Overall analysis suggests an association of the MTHFR C677T polymorphism with maternal risk for DS.
|
24913031 |
2014 |
|
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 |
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 |
Recent studies have linked the increased frequency of polymorphism of methylenetetrahydrofolate reductase (MTHFR, C677T) and methionine synthase gene (MTRR, A66G) in mothers with DS child.
|
12626825 |
2003 |
|
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 |
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 |
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 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 |
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 |
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 are consistent with the preliminary observation 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 1.91 (95% confidence interval [CI] 1.19-3.05).
|
10930360 |
2000 |