We evaluated the effects of vitamin D<sub>3</sub> (VD<sub>3</sub>) supplementation on morphofunctional aspects and the repercussions on the presence and localization of Aβ<sub>42</sub>, methylenetetrahydrofolate reductase (MTHFR), caspase-3 p12, and P-glycoprotein (Pgp) in the renal tissue of DS mouse model.
Present data suggest that MTHFR epimutations are likely to contribute to the increased genomic instability observed in cells from MDS, and could play a role in the risk of birth of a child with DS as well as in the onset of age related diseases in those women.
The frequency of the MTHFR 677C allele in DS mothers (79.8%) was significantly higher than in controls (66.3%), with a 0.499-fold increased risk of having a DS offspring (p=0.038 and 95% confidence interval [CI], 0.259-0.961).
Polymorphisms in certain folate-Hcy-pathway genes (especially the T allele of MTHFRC677T), 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.
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).
In addition, the combined TC 776CG and MTHFR 677TT genotype increased the risk of having a child with Down syndrome 3.64-fold (OR = 3.64; 95%CI = 1.28-10.31).
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.
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.
The frequency of MTHFRC677T 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).
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).
The combined MTRR 66G and MTHFR 677T alleles were significantly more common among mothers of children with DS than among control mothers (OR 1.55; IC 95% 1.03-2.35).
Functional inference of methylenetetrahydrofolate reductase gene polymorphisms on enzyme stability as a potential risk factor for Down syndrome in Croatia.
The combined MTHFR 677TT/MTR 2756AA genotype was associated with increased DS risk (P=0.034), and the combined MTHFR 1298AC/TYMS 2R/2R genotype with reduced risk (P=0.003).
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.
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.
The biochemical structure and function of methylenetetrahydrofolate reductase provide the rationale to interpret the epidemiological results on the risk for infants with Down syndrome.