Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neural Tube Defects”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed1989

Spinal ganglia reduction in the splotch-delayed mouse neural tube defect mutant.

Splotch and splotch-delayed mutants have anomalies in certain neural crest cell derivatives as well as neural tube defects. A genetic marker was used to identify mutant, heterozygote, and wild-type embryos within a litter, which enabled us to make intergenotypic comparisons. Histological studies of the lumbosacral region of day 15 and day 16 embryos indicated that the splotch-delayed mutant had similar but less severe defects in spinal ganglion development than those reported for splotch (Auerbach: Journal of Experimental Zoology 127:305-329, 1954). The ganglia were extensively reduced in size, residual, or missing in the splotch-delayed mutant, whereas in the splotch mutant, they were virtually nonexistent. Paired comparison analyses showed that all mutant embryos had a significant reduction in their volume of lumbosacral spinal ganglia when compared to their heterozygous and/or wild-type littermates. Also, some heterozygotes were found to have spinal ganglia volumes that were significantly reduced when compared to wild-type embryos. The volume of spinal ganglia was not related to the severity of the neural tube defect. In fact, three mutant embryos, which did not exhibit a neural tube defect, had spinal ganglia volumes comparable to or less than those mutants with open neural tube lesions or curly tails. This shows that the formation of abnormal neural crest cell derivatives is not a result of the neural tube closure defect. We hypothesize that the two anomalies observed in these mutants have a common etiological basis.

Animals↗
PubMedDate not supplied

Neural tube defects in trisomy 18.

In a retrospective survey, the incidence of neural tube defects in liveborn trimsomy 18 was found to be 6.2 per cent. Based on these data one would expect to find trisomy 18 in 1 of the 117 patients with myeloidysplasia; the incidence of trisomy 18 in dysraphic fetuses would be anticipated to be higher. These observations underscore the need for amniocentesis karyotyping of fetuses with neural tube defects, and the importance of careful examination of infants born with neural tube defects.

Adult↗
PubMed1999

Association of the 677C-->T mutation on the methylenetetrahydrofolate reductase gene in Turkish patients with neural tube defects.

We report the analysis of the 677C-->T mutation on the 5, 10-methylenetetrahydrofolate reductase gene in Turkish controls and cases of neural tube defects. Mutation analysis of 91 patients with neural tube defects, 72 mothers, 63 fathers, and 93 healthy controls has been made by polymerase chain reaction and allele specific restriction digestion with Hinf I. We did not find a significant difference in the 677C-->T allele and genotype distribution among the patients with neural tube defects, their parents, and the control group. This result suggests that another mutation in the folate-related enzyme genes could be responsible for neural tube defects in Turkey. None of the mothers of patients with neural tube defects was advised to use folic acid as recommended to prevent neural tube defects. An immediate attempt to establish an education program for healthcare providers and women of childbearing age is crucial in Turkey. Furthermore, fortification of foods with folate would be a better approach.

Adult↗
PubMed1997

Involvement of deprivation and environmental lead in neural tube defects: a matched case-control study.

OBJECTIVE: To analyse the prevalence of neural tube defects in small geographical areas and seek to explain any spatial variations with reference to environmental lead and deprivation. SETTING: The Fylde of Lancashire in the north west of England. DESIGN: Cases were ascertained as part of a prospective survey of major congenital malformations in babies born in the Fylde to residents there between 1957 and 1981. A matched case-control analysis used infants with cardiovascular system, alimentary tract, and urinary system malformations as controls. Conditional logistic regression was used to assess the effects of more than 10 micrograms/l lead in drinking water and the Townsend deprivation score. RESULTS: The prevalence of neural tube defects in 1957-73 was higher in Blackpool, Fleetwood, and North Fylde, whereas the three control groups showed no significant spatial variation. In 1957-81 mothers living in electoral wards with either a higher proportion of houses with more than 10 micrograms/l lead in the water or a higher deprivation score had a greater risk of having a baby with a neural tube defect. For spina bifida and cranium bifidum alone, this was also true. For anencephaly, deprivation was less important although the effect of lead was still seen. In some neural tube defects, lead may act independently of other possible factors associated with deprivation. It seemed unlikely that lead levels changed significantly during the survey. The percentage of houses with 10 micrograms/l or more of lead in the water in 1984-5 was similar to that found in Great Britain 10 years previously. CONCLUSION: There is evidence to suggest that lead is one cause of neural tube defects, especially anencephaly. This could link the known preventive actions of hard water and folic acid. Calcium is a toxicological antagonist of lead. One cause of a deficiency of folic acid is impaired absorption secondary to zinc deficiency, which may be produced or exacerbated by lead.

Anencephaly↗
PubMed2005

Recurrence risks for neural tube defects in siblings of patients with lipomyelomeningocele.

PURPOSE: Neural tube defects (NTDs) are a group of widely varying congenital malformations resulting from incomplete or improper fusion of the neural tube during embryonic development. NTDs are traditionally classified by the presence or absence of a layer of skin covering the spinal defect. Although a genetic component has been well established in the etiology of open NTDs, studies examining the genetics of closed NTDs such as lipomyelomeningocele are rare. We and others have previously observed families in which multiple members were affected with a broad spectrum of NTDs, suggesting the possibility of a common genetic etiology. METHODS: We calculated the sibling recurrence risk in 52 pedigrees in which the proband was diagnosed with lipomyelomeningocele (LMM), defining recurrence broadly to include both closed and open neural tube defects. RESULTS: Although no recurrences of LMM were observed among younger siblings, one younger sibling had myelomeningocele, yielding an estimate of recurrence risk of 0.04 (95% CI 0.01-0.20). When all siblings of the proband were included, two additional affected siblings were identified, one with anencephaly and another with fatty filum, yielding an estimate of recurrence risk of 0.043 (95% CI 0.01-0.12). CONCLUSIONS: Although the sample size is small, these data are not inconsistent with recurrence risks for myelomeningocele, ranging from 2% to 5% in siblings. These data suggest the underlying genetic basis for closed defects may be the same or closely related to that for myelomeningocele in some families, although a larger sample will be necessary before these data are appropriate for use in a clinical setting. Further characterizations, including whether risk for recurrence of NTDs or LMM in families in which the proband is affected with LMM are altered by folate supplementation, may shed light on the underlying genetics.

Case-Control Studies↗
PubMed2006

Histological evaluation of acute covering of an experimental neural tube defect with biomatrices in fetal sheep.

OBJECTIVE: The aim of the study was to determine the histological effect on the neural tissue of in utero covering of an experimental neural tube defect in fetal lambs, with the use of two different biomatrices. MATERIALS AND METHODS: In 23 fetal sheep, surgery was performed at 79 days' gestation. In 19 of these, a neural tube defect was created, while 4 fetuses served as sham-operated controls. In 7 of the 19 operated fetuses the defect was left uncovered. In the remaining 12 animals the defect was covered either with a collagen biomatrix (4 animals), skin (3 animals), or small intestinal submucosa biomatrix (5 animals). The lambs were sacrificed at 1 week of age and histological examination was performed. RESULTS: All lambs with an uncovered neural tube defect showed histological damage of the spinal cord. In lambs in which the neural tube defect was covered, one half showed a normal architecture of the spinal cord while minor histological damage was present in the other half. Between the three groups in which the defect was covered, the histological outcome was comparable. CONCLUSIONS: Acute covering of an experimental neural tube defect in fetal lambs prevents severe histological damage to the spinal cord independent of the two biomatrices used in this study.

Animals↗
PubMed1993

Periconceptional vitamin profiles are not suitable for identifying women at risk for neural tube defects.

Folic acid and other vitamin deficiencies may play a role in the etiology of neural tube defects. The Medical Research Council Vitamin Study confirmed the beneficial effect of folic acid supplementation on the prevention of neural tube defects. However, the concentrations of vitamins other than folate were not a common feature of any of the former studies. We measured the concentrations of vitamin A, riboflavin, riboflavine-5'-monophosphate, flavine-adenine-dinucleotide, vitamin B-6, vitamin B-12, vitamin C, vitamin E, folate and ferritin in the serum of women who had previously had a child with a neural tube defect and were planning a further pregnancy. Vitamin and folic acid supplements were supplied before conception to 44 high risk women before conception. Eighteen other high risk women not given supplements were the control group. We concluded that vitamin profiles do not form a suitable means for identifying women at risk for neural tube defects before pregnancy. This endorses the hypothesis that the beneficial effect of folic acid supplementation on the prevention of neural tube defects is possibly at least partly due to the fact that it overrides a relative folic acid shortage caused by a metabolic disorder.

Ascorbic Acid↗
PubMed2005

Neural tube defects in Pondicherry.

OBJECTIVE: This study was carried out to identify the trend and the frequency of neural tube defects from July 1998 to June 2004. METHODS: A total of 310 babies were born with neural tube defects with the overall frequency of 5.7/1000 births compared to 2.3/1000 births observed earlier in our hospital. RESULTS: The most common defect was spina bifida (54.8%) followed by anencephaly (31.6%), and encephalocele (11.6%). More neural tube defects were observed in female and low birth weight babies, still births and unbooked mothers. Neural tube defect was significantly higher among babies born to parents of consanguineous marriage (p< 0.01). Associated congenital defects were observed in thirty nine (12.6%) cases. CONCLUSION: The rise in the frequency of NTDS may indicate the current trend of NTDs in Southern India. A further prospective study is desired to measure the effectiveness of regular folic acid supplementation in bringing down this frequency.

Consanguinity↗
PubMed1980

Prenatal detection of neural tube defects. VI. Experience with 20,000 pregnancies.

Neural tube defects (NTDs) are among the most common major congenital malformations in the United States. Prenatal detection is possible in about 95% of cases by assaying amniotic fluid for alpha-fetoprotein (AFP), which leaks from open lesions. In 20,000 pregnancies, 334 (1.7%) had a raised level of AFP. Of these, 136 (40.7%) had open NTDs, 90 (26.9%) had other fetal defects or conditions, and 108 (32.3%) almost invariably had admixed fetal blood. Pregnancy was electively terminated in 11 cases in which the AFP concentration was thought to be elevated but in which the fetus was apparently normal (0.06%), but in only two of these cases was there no explanation for the raised level of AFP. The practical false-positive rate was considerably below 0.06%. Patients at risk for bearing children with NTDs should be counseled and offered prenatal diagnosis.

Amniotic Fluid↗
PubMed1994

Etiology and pathogenesis of human neural tube defects: insights from mouse models.

Research into neural tube defects (NTDs) is now entering a rapid phase as advances in experimental embryology and genetics, together with new insights from clinical epidemiology, provide testable hypotheses of the etiology and pathogenesis of these defects. Especially important have been contributions from the study of mouse mutants. The embryologic mechanisms responsible for upper and lower NTDs appear to be distinct, correlating with genetic evidence that distinguishes these phenotypes. The complex genetic etiology of NTDs may result from the effects of several modifier genes acting on a Mendelian trait of major effect, although no candidates are readily apparent for either type of gene. Clues to etiology have come from the preventive effect of nutritional supplements, especially those involved in one-carbon metabolism. More generally, research on NTDs has yielded major insights into how genetic predisposition can interact with environmental influences to modulate the incidence and severity of congenital malformations.

Animals↗
PubMed1987

Neural tube defects in rural Ireland.

The incidence of neural tube defects in a rural area of the west of Ireland from 1974 to 1985 was 2.96 per 1000. The prevalence was unchanged during the 11 years. When compared with a control group there was no increased incidence of anaemia in mothers of affected infants.

Female↗
PubMed2000

A deletion encompassing Zic3 in bent tail, a mouse model for X-linked neural tube defects.

Bent tail is a mouse model for human neural tube defects. Bent tail mice are characterized by a shortened, kinked tail. We have observed numerous aberrations in Bent tail embryos including exencephaly, rotation defects and occasionally omphalocele, orofacial schisis and situs abnormalities. Exencephaly was seen in >10% of all embryos and resulted from a closure defect of the hindbrain. Bent tail maps to the proximal part of the X chromosome. By haplotype analysis we have appointed the Bent tail locus to a 1.1 cM interval between markers DXMit159 and DXMit143. Subsequent analysis has revealed the presence of a deletion in all affected animals. The deletion is approximately 1 Mb in size and encompasses the gene for ZIC:3, a zinc finger transcription factor expressed in murine neuroectoderm and dorsal axial mesoderm during neurulation. ZIC:3 is a homolog of the Drosophila segmentation gene odd-paired. Although the Bent tail phenotype probably is the result of the deletion of several genes, combining data on ZIC:3 expression and function of ZIC: genes in the mouse shows that deletion of Zic3 alone is compatible with a major role of this gene in the congenital malformations of the Bent tail mouse. In man, mutations in ZIC3 are associated with situs abnormalities. These patients occasionally also show spina bifida, indicating that genetic variation in human ZIC3 may contribute to other congenital malformations, including neural tube defects.

Animals↗
PubMed1993

The epidemiology of neural tube defects. A mathematical model.

The incidence of neural tube defects (NTDs) shows a seasonal variation; and incidence as well as female/male ratio show a relation with latitude. The interrelation of these phenomena is presented as a mathematical model, which has a 'predictive' value, and is an instrument in estimating the local gene frequency. The model offers a simple explanation of the conundrum why the double X-chromosome has a variable influence on the sex ratio. UV light and the herpes virus fit in this model as related causative factors of NTDs.

Epidemiologic Factors↗
PubMed1994

Early sialylation on N-CAM in splotch neural tube defect mouse embryos.

The splotch (Sp) mutant mouse is a model for neural tube defects and Waardenburg syndrome type I. The neural tube defects that arise in Sp, which include spina bifida and exencephaly, are thought to be caused by a change in the timing of the cellular events which are taking place during neurulation. Cell adhesion molecules are strongly implicated in a variety of cell-cell interactions throughout development, thus the neural cell adhesion molecule (N-CAM) may play a role in neural tube formation and closure. The N-CAM in day 9 Sp embryos is altered showing a heavy 200 kD species rather than the 180 and 140 kD isoforms which are normally present at that developmental stage [Moase and Trasler (1991) Development 113:1049-1058]. These N-CAM isoforms normally become modified post-translationally by the addition of alpha-2,8 linked polysialosyl (PSA) units beginning at gestational day 11. Sp/Sp, Sp/+, and +/+ embryos were examined by Western blot analysis with an antibody (mAb 5A5) which specifically recognizes PSA residues on N-CAM. Mutant and heterozygote embryos display a sialylated N-CAM form at 20, 14, and 12 somite-stages which is absent in controls. Enzymatic removal of PSA on N-CAM resulted in a reduction of the 200 kD PSA-free N-CAM isoforms. These results in the observed 200 kD species, and suggest that the Sp gene is involved in the regulation of expression or the post-translational modification of N-CAM.

Animals↗
PubMed2004

An evaluation of maternal illnesses in the origin of neural-tube defects.

OBJECTIVE: The objective of the study was to estimate risk of acute and chronic maternal diseases during pregnancy in the origin of neural-tube defects. MATERIALS AND METHODS: Mothers with neural-tube defect fetuses/newborns (the NTD group), controls without any congenital defects (the normal control group) and controls with other defects (the other CA control group) were compared in the population-based data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. Of 1,202 cases with neural tube defects, 559 (49.8%) and 229 (19.1%) had mothers with one or more acute and chronic diseases, respectively. Of 38,151 mothers in the normal control group 14,004 (36.7%) and 8,328 (21.8%) had mothers with one or more acute or chronic diseases, respectively. Of 22,475 mothers in the other CA control group, 8,999 (40.0%) and 3,793 (16.9%) were affected with one or more acute or chronic maternal diseases, respectively. The prevalence of these diseases was evaluated in the 2nd months of gestation, however, if diseases occurred in the 1st month and continued in the 2nd month were also included. RESULTS: There was a potential recall bias between the NTD group and the normal control group, but not between the NTD group and the other CA control group. CONCLUSIONS: We suggest that maternal fever is a possible cause of neural-tube defects. Thus, these fevers should be treated with antipyretics during pregnancy. Among chronic maternal diseases, the possible association of migraine-headache, on the one hand and neural tube defects (particularly anencephaly) on the other hand cannot be excluded.

Acute Disease↗
PubMed1988

[Etiologic and epidemiologic aspects of neural tube defects].

A case-control study of neural tube defects (NTD) was undertaken from 1979 to 1986 in the department of Bas-Rhin in Northeastern France. For 105,374 consecutive births the incidence of spina bifida was 0.62 in 1,000, the incidence of anencephaly was 0.33 in 1,000 and that of encephalocele was 0.14 in 1,000. Sex ratios were respectively 1.06, 0.64 and 0.75. Among the numerous etiological factors which were studied we observed a seasonal factor (more conceptions in April, less in September). Birth weight and length were lower in children with spina bifida than in controls. Metrorrhagia was more frequent during pregnancies with anencephaly as was oligoamnios in pregnancies with encephalocele. Routine US prenatal diagnosis, which was performed in 90% of the pregnant women, allowed diagnoses in 88% of the fetuses with anencephaly but only in 53% of the fetuses with spina bifida and in 64% of the fetuses with encephalocele. For these last two anomalies diagnosis could often be performed because a malformation was associated with a NTD.

Female↗
PubMedDate not supplied

Bayesian small area cluster analysis of neural tube defects in Newfoundland.

BACKGROUND: The incidence of neural tube defects (NTDs) is declining worldwide due to the implementation of folic acid supplementation programs. Such a program was implemented over 1996-97 in Newfoundland and Labrador, Canada. The geographical distribution of birth incidence was studied prior to and after the implementation of the program to identify regions of residual high incidence. Excess residual cases may potentially be due to genetic causes or incomplete supplementation program implementation. METHODS: Maternal place of residence for all provincial live birth and stillbirth notifications, provincial maternal-fetal medicine referrals, provincial rehabilitation referrals, and all provincial hospitals with NTDs or terminations for NTDs was obtained from 1975 to 2002 for near complete case ascertainment. Bayesian small area analysis was separately performed on cases from 1975-1996 and 1997-2002. The two time periods were compared. RESULTS: Birth incidence of NTDs was noted to decline after 1996, from 5.54/1000 live births to 1.08/1000 live births. 592 cases were found from 1975-1996 and 34 cases from 1997-2002. Relative risk of birth incidence was 0.93-1.18 (95% CI) for 1975-1996 and 0.97-1.02 for 1997-2002 after Bayesian smoothing. One region had an excess of residual cases greater than 34%. CONCLUSIONS: The implications of this observation to the management of the public health initiative imply that overall response to the decrease in cases tends to be uniform across the province, with potentially one area of interest where extra efforts may be devoted.

Bayes Theorem↗