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PubMed1985

Transferrin and HLA: spontaneous abortion, neural tube defects, and natural selection.

We report evidence that transferrin C3, a gene present in 9 to 10 per cent of whites, is associated with recurrent spontaneous abortion (P = 0.001) and that maternal transferrin genotype has an effect on the transmission ratio of the common transferrin genes (C1, C2, and C3) from heterozygous fathers to normal offspring (P less than 0.002). The effect of maternal genotype on paternal gene transmission is an unusual example of the operation of selection in the human reproductive process. This effect, together with the separate evidence for association of the transferrin C3 allele with spontaneous abortion, indicates that transferrin is a second marker (in addition to HLA) of genes important in reproduction. On the basis of comparison of the frequencies of transferrin (chromosome 3) and HLA (chromosome 6) mating types in 348 control couples and in 81 couples who had had a child with a neural tube defect, we hypothesize that some combinations of maternal and fetal genes on these two chromosomes may be associated with neural tube defects.

Abortion, Habitual↗

PubMed2001

Spinal arachnoid cyst without neural tube defect.

Symptomatic arachnoid cysts of the spine are rare lesions in the pediatric age group. Although most commonly occurring in association with neural tube defects, such as myelomeningocele and diastematomyelia, in some cases the cysts appear in children without spinal anomalies. We describe a 12-month-old girl with lumbar intradural arachnoid cyst with progressive weakness of the lower limbs. There was full recovery after fenestration of the cyst.

Arachnoid Cysts↗

PubMed1985

False-positive amniotic fluid acetylcholinesterase results: the need for a multifacet approach to the prenatal diagnosis of neural tube defects.

Two cases are presented with false-positive amniotic fluid alpha-fetoprotein and acetylcholinesterase results for the prenatal diagnosis of neural tube defects. Stage II ultrasound revealed no lesions of the fetal spine in both cases. The alpha-fetoprotein and acetylcholinesterase results returned to normal on subsequent taps. Both pregnancies resulted in normal outcomes. A protocol is presented for managing pregnancies with abnormal alpha-fetoprotein and acetylcholinesterase results.

Acetylcholinesterase↗

PubMed1982

[Amniotic fluid acetylcholinesterase and prenatal diagnosis of neural tube defects. II. Qualitative test].

The qualitative acetylcholinesterase (AChE) test has been used in conjunction with alpha-fetoprotein (AFP) assay on 255 amniotic fluid samples: 191 from normal pregnancies, 44 from abnormal pregnancies (foetal anomalies or intrauterine death). In all cases of normal amniotic fluid obtained before 25 weeks, gel revealed a single major band of non specific cholinesterase, even in fluids contaminated by maternal of foetal blood, whereas 5 fluids contaminated by foetal blood were false positive on AFP. In 8 normal specimens with clear aspect, obtained after 25 weeks, gel revealed a second (AChE) faint band, inhibited by BW 284 C 51. That result shows the risk of false-positive for samples obtained in late pregnancy. All 20 cases of neural tube defect gave a characteristic AChE band: large and intense band. In 9 cases of abdominal wall defect, 3 presented an AChE faint band, just as 2 cases of atresia and 2 cases of hydronephrosis. Negative AChE results were found un 1 case of congenital nephrosis, 3 cases of hydrocephaly and 1 case of teratoma. The main value of qualitative AChE test seems today in diagnosing neural tube defects with a greater sensibility and in classifying bloody fluids in which the AFP is at or above the cut-off level.

Acetylcholinesterase↗

PubMed1997

Open neural tube defects: immunocytochemical demonstration of neuroepithelial cells in amniotic fluid.

Cytologic evaluation of second trimester amniotic fluid (AF) is a rapid, inexpensive adjunct to prenatal diagnosis of open neural tube defects (ONTDs). Our goal was to determine whether the neural-appearing cells and/or large foamy macrophages in the AF of anencephalics are indeed of neural and/or glial origin. In two second trimester patients with elevated serum alpha-fetoprotein (AFP) and polyhydramnios, fetal sonogram studies showed anencephaly; amniocentesis was performed for AF-AFP, cytogenetic, and cytologic studies. AF sediment smears were initially Papanicolaou-stained; next, the same smears were immunoperoxidase (IP)-stained for glial fibrillary acidic protein (GFAP). If GFAP negative, slides were restained for synaptophysin (SYN) and neuron-specific enolase (NSE). Both AFs contained small neural-appearing cells (5-10 microns) singly and in clusters, with dense, round, homogeneous nuclei, an occasional nucleolus, and scant cytoplasmic rim. These were GFAP negative and SYN and NSE positive; the large vacuolated, lipid-laden macrophages (20-40 microns) were negative for all three IP stains. In conclusion, positive IP staining for SYN and NSE supports the morphologic impression that small dark cells in AF are of neural origin, while negative IP staining of large foamy macrophages suggests nonneural, nonglial origin.

Amniotic Fluid↗

PubMedDate not supplied

Knowledge of periconceptional folic acid for the prevention of neural tube defects. The missing links. Northeastern Ontario Primary Care Research Group.

BACKGROUND: Periconceptional folic acid supplementation is effective in preventing primary and secondary neural tube defects (NTDs) and other congenital defects. However, debate exists regarding the effectiveness of public and physician education on patient knowledge and compliance. OBJECTIVE: To examine the level of knowledge about the usefulness of periconceptional folic acid supplementation in a sample of patients from primary care practices. DESIGN: Cross-sectional survey. A confidential, anonymous questionnaire was completed by patients before physician encounters. A maximum of 20 consecutive female patients from each of 3 age groups (16-24, 25-32, and 33-40 years) were recruited from each primary care practice. SETTINGS: Twenty-two Canadian teaching practices affiliated with the Northeastern Ontario Primary Care Research Group. OUTCOME: Women's knowledge of periconceptional folic acid supplementation for the prevention of NTDs. RESULTS: Of 1125 eligible female patients between the ages of 16 and 40 years visiting their family physician in 1996, 1124 (99.9%) completed the questionnaire. General awareness of NTDs was high (62.7%); however, knowledge that these defects were preventable was lower (22.5%). Only 7.8% of the women made the association between folic acid intake and NTDs. The specific knowledge that NTDs could be prevented with folic acid supplementation before conception was identified by 1.8% of the sample. Pregnant participants were at least twice as likely to be informed about the link. Interpractice variability existed with respect to knowledge of folic acid supplementation. CONCLUSION: Knowledge of periconceptional folic acid supplementation for the prevention of NTDs was low in this sample and is likely to be reflected in missed opportunities to prevent an important class of congenital malformations.

Adolescent↗

PubMedDate not supplied

Justification of maternal serum alphafetoprotein screening in a population with low incidence of neural tube defects.

A prospective study of maternal serum alphafetoprotein (alpha-FP) screening of 9838 women in an area with low prevalence of neural tube defects and predominance of anencephalics revealed that an intervention point of single serum alpha-FP level above 2.8 times the median was appropriate for this population. Ninety per cent of anencephalics and all fetuses with anterior abdominal wall defects were detected. There was no spina bifida among the population screened. Two per cent of the population screened had serum alpha-FP level above this cut-off level. Thirty-two per cent of twin pregnancies, 7 per cent of small-for-gestational age infants and 9 per cent of pregnancies which ended in either abortion or perinatal death in the population screened also had one serum alpha-FP level above this intervention point. The false positive rate was 66 per cent. This false positive rate was only reduced to 63 per cent if instead of one, two serum alpha-FP level above this intervention point was considered abnormal. Using this strategy there was no significant reduction in the detection rate of fetal anomalies and other pregnancy complications. Because of the predominance of anencephalics in this population the diagnosis of fetal anomaly in women with abnormal serum alpha-FP level was made by ultrasound examination alone. The reason amniocentesis was not performed in these patients was to avoid unnecessary loss of normal pregnancies which may result from this procedure.

Anencephaly↗

PubMed1981

Acetylcholinesterase and butyrylcholinesterase measurement in the pre-natal detection of neural tube defects and other fetal malformations.

Acetylcholinesterase activity in amniotic fluid was measured at 30 degree C by a reaction rate method employing acetyl-beta-methyl thiocholine as substrate and ethopropazine as a selective inhibitor of butyrylcholinesterase. This assay proved more specific than previously reported methods. Activity was greater in five cases of anencephaly (4.8-9.7 U/l) and nine cases of spinal bifida (5.1-8.6 U/l) than in 50 pregnancies with normal outcome (mean activity 2.0 +/- 0.9 (S.D.) U/l). There was no overlap between results from normal and neural-tube-defect groups, and the results showed no significant correlation with gestational age. Butyrylcholinesterase activity in amniotic fluid was measured using butyrylthiocholine as substrate. In accordance with previous reports, levels were elevated in pregnancies affected by neural tube defects. The ratio butyrylcholinesterase/acetylcholinesterase activity showed similar values for anencephalic, spina bifida and normal pregnancies; however, the two cases of exomphalos investigated could be clearly distinguished from all other groups on this basis.

Acetylcholinesterase↗

PubMed1973

Area differences in spontaneous abortion rates in South Wales and their relation to neural tube defect incidence.

Data are presented from the South Wales Congenital Malformation Survey (92,982 births 1964-6 inclusive) showing that within areas in South Wales there exists an inverse relation between previous spontaneous abortion rate and the prevalence at birth of neural tube defect (anencephaly or spina bifida cystica or both). This relation is independent of social class, parity, and maternal age, and is not likely to be explained by area differences in accuracy of reporting previous spontaneous abortions.On the basis of these findings a hypothesis is advanced which proposes that the incidence of neural tube defects is uniform throughout South Wales and that the present substantial and relatively stable differences in area prevalence are controlled by small area differences in mortality of malformed embryos. This would seem to suggest that factors initiating the malformation are genetic and that any related environmental factors exert their effect on already abnormal fetuses by influencing, in one way or another, their capacity to survive.

Abortion, Spontaneous↗

PubMed1983

Occurrence of neural tube defects among first-, second-, and third-degree relatives of probands: results of a United States study.

Data on the occurrence of neural tube defects in first-, second-, and third-degree relatives of probands were collected in a United States study. The proportions of affected individuals were 3.2%, 0.5%, and 0.17% respectively. These findings are compared to those from other recent North American studies, and differences are discussed. It is pointed out that accurate recurrence risk figures may not be available, and that caution should be used when counseling families with relatives who are affected with NTD.

Cleft Lip↗

PubMed1979

Current experience of neural tube defects in the West of Scotland.

The experience at the Royal Hospital for Sick Children,Glasgow, of infants admitted due to a neural tube defect has been reviewed. Two hundred and seventy-one infants were admitted in the years 1972 to 1978. In 1972 amniocentesis and in 1975 serum AFP screening were commenced in the region. Analysis of the results in Glasgow shows the latter programme to have resulted in the termination of 78% of these pregnancies complicated by the fetus having anencephaly but only 19% of those with spina bifida cystica. Spina bifida patients are a continuing medical and social challenge for which continued resources must be deployed.

Female↗

PubMed2005

Spontaneous neural tube defects in splotch mice supplemented with selected micronutrients.

Splotch (Sp/Sp) mice homozygous for a mutation in the Pax3 gene inevitably present with neural tube defects (NTDs), along with other associated congenital anomalies. The affected mutant embryos usually die by gestation days (E) 12-13. In the present study, the effect of modifier genes from a new genetic background (CXL-Sp) and periconceptional supplementation with selected micronutrients (folic acid, 5-formyltetrahydrofolate, 5-methyltetrahydrofolate, methionine, myoinositol, thiamine, thymidine, and alpha-tocopherol) was determined with respect to the incidence of NTDs. In order to explore how different exposure parameters (time, dose, and route of compound administration) modulate the beneficial effects of micronutrient supplementation, female mice received either short- or long-term nutrient supplements via enteral or parenteral routes. Embryos were collected on E12.5 and examined for the presence of anterior or posterior NTDs. Additionally, whole mount in situ hybridization studies were conducted in order to reveal/confirm normal expression patterns of the Pax3 gene during neurulation in the wild-type and Sp/Sp homozygous mutant mouse embryos utilized in this study. A strong Pax3 signal was demonstrated in CXL-Sp embryos during neural tube closure (E9.5 to E10.5). The intensity and spatial pattern of expression were similar to other Splotch mutant mice. Of all the micronutrients tested, only supplementation with folic acid or 5-methyltetrahydrofolate rescued the normal phenotype in Sp/Sp embryos. When the folate supplementation dose was increased to 200 mg/kg in the diet, the incidence of rescued splotch homozygotes reached 30%; however, this was accompanied by six-fold increased resorption rate.

Animals↗

PubMed1982

Serum cholinesterase in the mothers of neural tube defect progeny.

Human Serum Cholinesterase activity and polymorphism at its two gene loci, CHE1 and CHE2, were compared in maternal serum from neural tube defect pregnancies, normal pregnancies and a non-pregnant control group. Variants at the CHE1 locus were identified by dibucaine, fluoride and R02 0683 inhibition. The CHE2 phenotype was demonstrated by DISC polyacrylamide gel electrophoresis. Total HSChE activity in the pregnant groups was slightly less than in the control group but there was no difference in activity between the affected and the normal pregnancies. Three variants were identified. All were found in the non-affected pregnant group. One variant at CHE1 was identified, an I phenotype, and two C5+ phenotypes, the CHE2 variant. No obvious relationships were found between HSChE activity or a particular genetic variant and NTD progeny.

Cholinesterases↗

PubMed1998

Neural tube defects and congenital hydrocephalus in the Sultanate of Oman.

A retrospective study was carried out in Oman to determine the incidence of neural tube defects (NTD) and congenital hydrocephalus (CH) and to identify any possible associations. National data retrieved from hospital records revealed the incidence of NTD in Oman to be comparatively low (1.25 per 1000), but the incidence of CH was much higher than that seen in Western Europe (0.44 per 1000) and was found to be associated with high rates of other congenital anomalies and neonatal death. There were no specific environmental factors associated with NTD and high environmental temperatures during the tropical desert summer (temperatures reach 48 degrees C) were excluded as a causative factor. In spina bifida families, later born children were more likely to be affected and there was also an association with increased maternal but not paternal age. Much higher consanguinity rates were noted in families with NTD and CH than in the general population.

Cohort Studies↗

PubMed1981

Particulate acetylcholinesterase in amniotic fluid and its implications for neural tube defect screening.

Acetylcholinesterase activity in mid-trimester amniotic fluid has been determined by a quantitative spectrophotometric method and a qualitative electrophoretic technique in a limited (76 samples) retrospective study. Differential centrifugation studies on amniotic fluid from normal pregnancies demonstrated the presence of particle-associated acetylcholinesterase sedimenting only at relatively high centrifugal forces. It is postulated that this particle-associated activity was a contributory factor to an observed false-positive incidence of 6.6% when quantitative acetylcholinesterase measurement was used to discriminate between normal pregnancies and those associated with neural tube defects. Discrimination on the basis of electrophoretic analysis of acetylcholinesterase resulted in no misclassification of pregnancies. Particulate acetylcholinesterase would not be expected to influence the interpretation of the electrophoretic pattern due to its size-related exclusion from gel pores. The implication of these observations in the accurate prenatal diagnosis of neural tube defects is discussed.

Acetylcholinesterase↗

PubMed2003

Rescue of the neural tube defect of loop-tail mice by a BAC clone containing the Ltap gene.

The mouse mutant loop-tail (Lp) is an accepted model for the study of neural tube defects (NTDs) in humans. Whereas Lp/+ heterozygotes show a mild tail defect (looped), homozygous Lp/Lp embryos show a very severe form of NTD, with a completely open neural tube from the hindbrain region to the caudal portion of the spinal cord (craniorachischisis). We have recently identified a positional candidate for Lp on chromosome 1, designated as Ltap. Here, we have used an in vivo complementation approach in transgenic mice to attempt to correct the looped-tail phenotype with a bacterial artificial chromosome clone (BAC280A23) that harbors a full-length copy of the Ltap gene. Genotype:phenotype correlations in Lp/+ heterozygotes carrying BAC280A23 show that this clone can rescue the looped-tail phenotype in two independent founder lines (P < 0.05 and P < 0.0001). Importantly, BAC280A23 is also observed to rescue the lethal NTD of Lp/Lp homozygotes, because several viable transgenic Lp/Lp mice could be identified and appeared normal (P < 0.05). Results from these gain-of-function transgenic animals strongly suggest that the positional candidate Ltap present in this BAC is indeed the gene that is defective in loop-tail.

Animals↗

PubMed1995

Prevalence of neural tube defects in northeastern France, 1979-1992 impact of prenatal diagnosis.

The objective of this study was to determine in total prevalence of neural tube defects (NTD) in northeastern France during 1979-1992 inclusive, the impact of prenatal diagnosis on birth prevalence. All births and termination of pregnancy affected by NTD were ascertained from multiple sources thank to our registry of congenital anomalies. In our region maternal serum alpha-fetoprotein screening is not available whereas routine ultrasonographic screening of congenital anomalies is performed in all pregnant women. Total prevalence of NTD during 1979-1992 was 10.94 per 10,000 with no upward or downward trend. The total prevalence of NTD in our region remained stable. However birth prevalence fell significantly. The fall was 100 per cent for anencephaly and 60 and 50 per cent for spina bifida and encephalocele, respectively. This decrease was obtained by routine ultrasonographic examination only and termination of pregnancy. Comparison with similar studies in other countries demonstrated that screening by maternal serum alpha-fetoprotein is needed in our region.

Evaluation Studies as Topic↗

PubMed1997

Prevalence of neural tube defects in northeastern France, 1979-1994. Impact of prenatal diagnosis.

The objective of this study was to determine in total prevalence of neural tube defects (NTD) in northeastern France during 1979-1994 inclusive, the impact of prenatal diagnosis on birth prevalence. All births and termination of pregnancy affected by NTD were ascertained from multiple sources thank to our registry of congenital anomalies. In our region maternal serum alpha-fetoprotein screening is not available whereas routine ultrasonographic screening of congenital anomalies is performed in all pregnant women. Total prevalence of NTD during 1979-1994 was 10.73 per 10,000 with no upward or downward trend. The total prevalence of NTD in our region remained stable. However birth prevalence fell significantly. The fall was 100 per cent for anencephaly and 60 per cent for spina bifida. This birth prevalence was unchanged for encephalocele. This decrease for anencephaly and spina bifida was obtained by routine ultrasonographic examination only and termination of pregnancy. Comparison with similar studies in other countries demonstrated that screening by maternal serum alpha-fetoprotein is needed in our region.

Female↗