Neural tube defects: prevention by folic acid and other vitamins.
ABSTRACT Folic acid has been demonstrated in clinical trials to reduce significantly the recurrence (and probably occurrence) of neural tube defects (NTD). In the U.K., there has been no decline in prevalence of NTD since the publication of the findings with folic acid. This article examines a series of questions relating to the action of folic acid, with emphasis on the use of mouse models as a source of experimental information which cannot easily be obtained by direct study of humans. Several mouse genetic NTD models exhibit sensitivity to prevention by folic acid, whereas other mice which develop morphologically similar NTD are resistant. Folic acid normalises neurulation in the sensitive mouse strains, providing evidence for a direct effect on the developing embryo, not on the pregnant female: Mouse studies do not support the proposed action of folic acid in encouraging the in utero demise of affected fetuses (i.e. terathanasia). Polymorphic variants of several folate-related enzymes have been shown to influence risk of NTD in humans and an inherited abnormality of folate metabolism has been demonstrated in one mouse NTD model. However, the biochemical basis of the action of folic acid in preventing NTD remains to be determined in detail. NTD in one folate-resistant mouse strain can be prevented by myo-inositol, both in utero and in vitro, raising the possibility of a therapeutic role also in humans. Gene-gene interactions seem likely to underlie the majority of NTD, suggesting that poly-therapy involving folic acid and other agents, such as myo-inositol, may prove more effective in preventing NTD than folic acid treatment alone.
Full-textDOI: · Available from: Andrew J Copp, May 30, 2015
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ABSTRACT: Periconceptional supplementation with folic acid has led to a significant worldwide reduction in the incidence of neural tube defects (NTDs). However, despite increasing awareness of the benefits of folic acid supplementation and the implementation of food fortification programs in many countries, NTDs continue to be a leading cause of perinatal morbidity and mortality worldwide. Furthermore, there exists a significant subgroup of women who appear to be resistant to the protective effects of folic acid supplementation. The following review addresses emerging clinical and experimental evidence for a role of the immune system in the etiopathogenesis of NTDs, with the aim of developing novel preventative strategies to further reduce the incidence of NTD-affected pregnancies. In particular, recent studies demonstrating novel roles and interactions between innate immune factors such as the complement cascade, neurulation, and folate metabolism are explored. Birth Defects Research (Part A) 97:602-609, 2013. © 2013 Wiley Periodicals, Inc.Birth Defects Research Part A Clinical and Molecular Teratology 09/2013; 97(9):602-9. DOI:10.1002/bdra.23177 · 2.21 Impact Factor
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ABSTRACT: Assuming that spina bifida (SB) is a genetically controlled disease, the aim of our study was to evaluate the degree of genetic homozygosity and the distribution of AB0 blood types among patients with SB occulta and SB aperta by the homozygously recessive characteristics (HRC) test. Our study included an analysis of the presence, distribution and individual combination of 15 selected genetically controlled morpho-physiological traits in a sample of 100 patients with SB (SB occulta N = 50 and SB aperta N = 50) and a control group of individuals (N = 100). We found a statistically significant difference between the mean values for genetic homozygosity (SB 4.5 ±0.3; control 3.0 ±0.2, p < 0.001) and also differences in the presence of certain individual combinations of such traits. In 12 (80.0%) of the 15 observed characteristics, recessive homozygosity was expressed to a greater degree among the group of SB patients, while for 9 (60.0%) of the traits this level of difference was statistically significant (Σ(χ) (2) = 266.3, p < 0.001). There was no difference in average homozygosity of such genetic markers between groups of SB occulta and SB aperta patients, but the type of individual variation in the two studied groups significantly differed. In the group of patients with SB the frequency of 0 blood group was significantly increased while B blood group was significantly decreased. Our results clearly show that there is a populational genetic difference in the degree of genetic homozygosity and variability between the group of patients with SB and individuals without clinical manifestations, indicating a possible genetic component in the aetiopathogenesis of spina bifida.Archives of Medical Science 12/2010; 6(6):854-9. DOI:10.5114/aoms.2010.19291 · 1.89 Impact Factor
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ABSTRACT: We compared individual trait variability in 65 male and 81 female patients with spina bifida occulta (SBO) or spina bifida aperta (SBA) against 170 male and 200 female subjects randomly selected Serbian subjects without these conditions. Variability was evaluated by direct observation of 15 homozygous recessive traits (HRT), while gender was evaluated separately. Individual trait variations between genders in SBO patients (4/15 HRT) and in SBA patients (12/15 HRT) showed remarkable differences. Individual trait variations between the male control group and SBO (9/15 HRT), between the female control group and SBO (5/15 HRT), between the male control group and SBA (8/15 HRT), between the female control group and SBA (9/15 HRT), between male SBO and SBA patients (6/15 HRT), between female SBO and SBA patients (6/15 HRT), also indicated remarkable differences. These differences could be explained by different expression of genes that may contribute to expression of spina bifida (SB).Balkan Journal of Medical Genetics 06/2011; 14(1):11-8. DOI:10.2478/v10034-011-0012-5 · 0.17 Impact Factor