Neural Tube Defects

2018 ◽  
Author(s):  
Jimmy Hoang ◽  
Samuel David Yanofsky
Keyword(s):  
Spina Bifida ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Congenital Abnormalities ◽  
Spinal Dysraphism ◽  
Neural Tube Closure ◽  
Increased Risk ◽  
Spina Bifida Cystica ◽  
The Brain ◽  
Is Failure

Neural tube defects (NTDs) are congenital abnormalities that arise from the neural tube failing to close. These defects can affect the brain, spine, or spinal cord and generally happen within the first month of pregnancy. Cranial dysraphism is failure of cranial neural tube closure and includes anencephaly and encephalocele. Spinal dysraphism is failure of caudal neuropore closure and includes spina bifida cystica and occulta. Myelomeningocele is a type of spina bifida cystica where the membranous sac containing neural tissue protrudes through an opening in the back. It is the most common NTD and considered a surgical emergency due to the increased risk for infection, further neurologic damage, and dehydration. Advancements in medicine have allowed for the possibility of early diagnosis and even in utero surgical intervention. This chapter focuses more exclusively on the approach and management of myelomeningocele.

scholarly journals Mengenal Spina Bifida dan Pencegahannya

2021 ◽  
Vol 1 (12) ◽  
pp. 896-903
Author(s):  
Genta Faesal Atsani ◽  
Zanetha Mauly Ilawanda ◽  
Ilma Fahira Basyir
Keyword(s):  
Spina Bifida ◽  
Birth Defects ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Congenital Abnormality ◽  
Congenital Abnormalities ◽  
Folic Acid Supplementation ◽  
Online Portal ◽  
The Brain ◽  
Developing Spinal Cord

Neural tube defects (NTD) are one of the birth defects or congenital abnormalities that occur in the brain and spine, and commonly find in newborns worldwide. Anencephaly and spina bifida are the two prevalent forms of NTD. The incidence of spina bifida happen on average 1 in 1000 cases of birth worldwide and there are 140,000 cases per year worldwide. Source searches were carried out on the online portal of journal publications as many as 20 sources from MedScape, Google Scholar and the Nation Center for Biotechnology Information / NCBI with the keywords “Neural tube defects (NTD), prevention, and spina bifida”. Spina bifida is a congenital abnormality that occurs in the womb due to a failure of closing process the neural tube during the first few weeks of embryonic development which causes the spine not completely close around the developing spinal cord nerves. NTD can ensue multifactorial conditions such as genetic, environmental, and folate deficiency. The use of folic acid supplementation starting at least 3 months before pregnancy, those are 400 mcg (0.4 mg) per day and 800 mcg per day during pregnancy can reduce the risk of developing neural tube defects such as spina bifida. Generally, spina bifida is undertaking by surgery and the regulation of patients comorbid. Public can find out prevention to avoid or reduce the risk of spina bifida so that the incidence of spina bifida can decrease along with the increasing awareness of the community regarding this disease.

Spina Bifida and Related Conditions

2017 ◽  
Author(s):  
Stephen L. Kinsman
Keyword(s):  
Spinal Cord ◽  
Spina Bifida ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Spinal Dysraphism ◽  
Gene Interactions ◽  
Tethered Spinal Cord ◽  
Spinal Lesion ◽  
Gene Environment ◽  
Spina Bifida Aperta

The term “spinal dysraphism” encompasses the broadest array of the conditions known as the neural tube defects. The open neural tube defects (spina bifida aperta and cystica) include both disorders of primary and/or secondary neuralation and are best defined as myelomeningocele complex (MMC) due to their protean nervous system manifestations beyond the spinal lesion. Closed spinal dysraphisms (so-called spina bifida occulta) include lipomatous lesions, forms of tethered spinal cord, sinus tracts, and forms of split spinal cord (diastematomyelia). Both genetic and environmental etiologies have been identified. Gene-environment and gene-gene interactions are also important in the pathobiology of these conditions.

scholarly journals Recent perspectives on the development of the central nervous system and the genetic background of neural tube defects

2009 ◽  
Vol 150 (19) ◽  
pp. 873-882 ◽  
Author(s):  
József Gábor Joó
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Planar Cell Polarity ◽  
Genetic Basis ◽  
Neural Tube Closure ◽  
Increased Risk ◽  
Underlying Causes ◽  
The Central Nervous System

Neural tube defects are rare and mostly lethal malformations. The pattern of inheritance of these malformations is multifactorial, rendering the identification of the underlying causes. Numerous studies have been conducted to elucidate the genetic basis of the development of the central nervous system. Essential signaling pathways of the development of the central nervous system include the planar cell polarity pathway, which is important for the initiation of neural tube closure as well as well as sonic hedhehog pathway, which regulates the neural plate bending. Genes and their mutations influencing the different stages of neurulation have been investigated for their eventual role in the development of these malformations. Among the environmental factors, folic acid seems to be the most important modifier of the risk of human neural tube defects. Genes of the folate metabolism pathways have also been investigated to identify mutations resulting in increased risk of NTDs. In this review the author has attempted to summarize the knowledge on neural tube defects, with special regard to genetic factors of the etiology.

scholarly journals MiR-324–5p Regulation in Disturbed Embryogenesis Induced by Folate Deficiency

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1279-1279
Author(s):  
Li Wang ◽  
Shao-Yan Chang ◽  
Ting Zhang
Keyword(s):  
Dna Methylation ◽  
Spina Bifida ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Target Genes ◽  
Folate Deficiency ◽  
Neural Tube Closure ◽  
Shanxi Province ◽  
Mice Model ◽  
Deficiency Group

Abstract Objectives Folate plays key role during embryogenesis. It is proved that folate deficiency is a risk factor for birth defects mainly exerting its effects through DNA methylation. Here, we want to discover the epigenetic process of DNA methylation in the regulation of miRNAs and thereby regulates neural tube closure through actions on target genes. Methods 40 fetuses with spina bifida and 46 control fetuses from Shanxi Province in China were enrolled to study miR-324–5p alternations with folate deficiency. Meanwhile, mice model with folate deficiency diet were built to study the effects and possible mechanisms of pregnancy folate deficiency. Overexpressed miR-324–5p zebras model were used to detected the role of miR-324–5p during embryogenesis. And disturbed folic acid metabolism cell and mice model were used to confirm the mechanisms of miR-324–5p in neural tube defects induced by folate deficiency. Results We observed decreased miR-324–5p methylation in the brains of individuals with spina bifida. Hypomethylation of miR-324–5 increased the risk of spina bifida, with an odds ratio of 7.0 (95% CI: 2.10–23.36; P < 0.0001). A positive correlation between miR-324–5p methylation and folate levels were verified, and higher folate concentration reversed miR-324–5p alternations. We also observed increased miR-324–5p expression in the folate deficiency group, with concomitant decreased expression of its putative target genes, GLI1 and SMO. Furthermore, overexpression of miR-324–5p induced neural tube defects with inhibition of cell proliferation and migration. Similarly, we confirmed suppression of GLI1 and SMO expression in the brain of individuals with spina bifida. Conclusions The effect of folate deficiency on neural tube development may be mediated by miR-324–5p and its target genes. Funding Sources The National Natural Science Fund of China (81,670,802/H0724), National Key Research and Developmwnt Program (2016YFC1000502).

scholarly journals The prevention of neural tube defects by folic acid supplementation

Curationis ◽  
1993 ◽  
Vol 16 (4) ◽  
Author(s):  
H. W. Hitzeroth
Keyword(s):  
South Africa ◽  
Folic Acid ◽  
Spina Bifida ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Neural Tube Defect ◽  
Rural Areas ◽  
Congenital Abnormalities ◽  
Folic Acid Supplementation ◽  
Acid Supplementation

Neural tube defects, in particular spina bifida and anencephaly, are serious and relatively common congenital abnormalities worldwide. They also occur in South Africa and affect all population groups to varying degrees. The overall incidence in South Africa is approximately 1-2 per 1000 newborns. Higher incidences, up to 6 per 1000 newborns have been recorded in certain parts, especially in some rural areas of the country. In total as many as 1500 newborns could be affected by a neural tube defect each year. The precise aetiology of neural tube defects is still unknown.

scholarly journals Fetal Pathology of Neural Tube Defects – An Overview of 68 Cases

2017 ◽  
Vol 77 (05) ◽  
pp. 495-507 ◽  
Author(s):  
Katharina Schoner ◽  
Roland Axt-Fliedner ◽  
Rainer Bald ◽  
Barbara Fritz ◽  
Juergen Kohlhase ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Spina Bifida ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Spinal Dysraphism ◽  
Mendelian Inheritance ◽  
Sex Distribution ◽  
Risk Of Recurrence ◽  
Empirical Risk ◽  
Fetal Pathology

Abstract Introduction The prevalence of neural tube defects worldwide is 1 – 2 per 1000 neonates. Neural tube defects result from a disturbance of neurulation in the 3rd or 4th week of development and thus represent the earliest manifestation of organ malformation. Neural tube defects (NTD) are classified into cranial dysraphism leading to anencephaly or meningoencephalocele and spinal dysraphism with or without meningomyelocele. In isolated form they have multifactorial causes, and the empirical risk of recurrence in Central Europe is 2%. As associated malformations they tend to occur sporadically, and in monogenic syndromes they follow Mendelian inheritance patterns with a high risk of recurrence. Patients Autopsies were performed on 68 fetuses following a prenatal diagnosis of NTD and induced abortion. Results The incidence of NTDs in our autopsied fetuses was 8% and 11% in fetuses with malformations. The percentage of fetuses with anencephaly, encephalocele or spina bifida was 24, 18, and 60%*, respectively. Analysis of the sex distribution showed a female preponderance in cranial dysraphisms but the sex distribution of spina bifida cases was equal. The extent and localization of NTDs varied, with lumbosacral cases clearly predominating. The proportion of isolated, associated and syndromic neural tube defects was 56, 23.5 and 20.6% respectively. In the majority of syndromes, the neural tube defect represented a not previously observed syndromic feature. Conclusion The high proportion of NTDs with monogenic background underlines the importance of a syndrome oriented fetal pathology. At the very least it requires a thourough photographic and radiographic documentation of the fetal phenotype to enable the genetic counsellor to identify a syndromic disorder. This is necessary to determine the risk of recurrence, arrange confirming mutation analyses and offer targeted prenatal diagnosis in subsequent pregnancies.

Modifier locus for exencephaly in Cecr2 mutant mice is syntenic to the 10q25.3 region associated with neural tube defects in humans

2007 ◽  
Vol 31 (2) ◽  
pp. 244-251 ◽  
Author(s):  
Courtney E. Davidson ◽  
Qian Li ◽  
Gary A. Churchill ◽  
Lucy R. Osborne ◽  
Heather E. McDermid
Keyword(s):  
Spina Bifida ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Genetic Background ◽  
Single Gene ◽  
Neural Tube Closure ◽  
Whole Genome ◽  
Chromosome 19 ◽  
Modifier Locus ◽  
Splotch Mutation

Neural tube defects (NTDs), the second most common birth defect in humans, are multifactorial with complex genetic and environmental causes, although the genetic factors are almost completely unknown. In mice, >100 single gene mutations cause NTDs; however, the penetrance in many of these single gene mutant lines is highly dependent on the genetic background. We previously reported that a homozygous Cecr2 mutation on a BALB/c background causes exencephaly at a frequency of 74% compared with 0% on an FVB/N background. We now report that a major genetic modifier on chromosome 19, mapped using whole genome linkage analysis, increases the relative risk of exencephaly by 3.74 times in homozygous BALB embryos vs. BALB/FVB heterozygotes. Scanning electron microscopy revealed that the modifier does not affect the location of neural tube closure site 2, a known murine susceptibility factor for exencephaly. Crossing the Sp ( Splotch) mutation in the Pax3 gene onto the FVB/N background for two generations indicated that this resistant strain also decreases the penetrance of spina bifida. The chromosome 19 modifier region corresponds to a linkage region on human chromosome 10q25.3 mapped in a whole genome scan of human NTD families. Since the FVB/N genetic background affects susceptibility to both exencephaly and spina bifida, the human homolog of the chromosome 19 modifier locus may be a better candidate for human NTD susceptibility factors than genes that when mutated actually cause NTDs in mice.

scholarly journals Novel mouse model of encephalocele: post-neurulation origin and relationship to open neural tube defects

2019 ◽  
Author(s):  
Ana Rolo ◽  
Gabriel L. Galea ◽  
Dawn Savery ◽  
Nicholas D. E. Greene ◽  
Andrew J. Copp
Keyword(s):  
Spina Bifida ◽  
Mouse Model ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Small Gtpase ◽  
Late Gestation ◽  
Neural Tube Closure ◽  
Surface Ectoderm ◽  
Open Spina Bifida ◽  
Tube Closure

ABSTRACTEncephalocele is a clinically important birth defect that can lead to severe disability in childhood and beyond. The embryonic pathogenesis of encephalocele is poorly understood and, while usually classified as a ‘neural tube defect’, there is conflicting evidence on whether encephalocele results from defective neural tube closure, or is a post-neurulation defect. It is also unclear whether encephalocele can result from the same causative factors as anencephaly and open spina bifida, or whether it is aetiologically distinct. This lack of information results largely from the scarce availability of animal models of encephalocele, particularly ones that resemble the commonest, non-syndromic human defects. Here we report a novel mouse model of occipito-parietal encephalocele, in which the small GTPase Rac1 is conditionally ablated in the (non-neural) surface ectoderm. Most mutant fetuses have open spina bifida, and some also exhibit exencephaly/anencephaly. However, a large proportion of mutant fetuses exhibit encephalocele affecting the occipito-parietal region. The encephalocele phenotype does not result from a defect in neural tube closure, but rather from a later disruption of the surface ectoderm covering the already closed neural tube, allowing the brain to herniate. The neuroepithelium itself shows no down-regulation of Rac1 and appears morphologically normal until late gestation. A large skull defect develops overlying the region of brain herniation. Our work provides a new genetic model of occipito-parietal encephalocele, particularly resembling non-syndromic human cases. While encephalocele has a different, later-arising pathogenesis than open neural tube defects, both can share the same genetic causation.SUMMARY STATEMENTEncephalocele - a severe brain defect - arises after neural tube closure, but can share a common genetic cause with anencephaly, a defect of neural tube closure.

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