Neural Tube Defect Group Research Articles

Identifying key m6A-methylated lncRNAs and genes associated with neural tube defects via integrative MeRIP and RNA sequencing analyses.

Objective: N6-methyladenosine (m6A) is a common post-transcriptional modification of messenger RNAs (mRNAs) and long non-coding RNAs (lncRNAs). However, m6A-modified lncRNAs are still largely unexplored. This study aimed to investigate differentially m6A-modified lncRNAs and genes involved in neural tube defect (NTD) development. Methods: Pregnant Kunming mice (9-10 weeks of age) were treated with retinoic acid to construct NTD models. m6A levels and methyltransferase-like 3 (METTL3) expression were evaluated in brain tissues of the NTD models. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) were performed on the NovaSeq platform and Illumina HiSeq 2,500 platform, respectively. Differentially m6A-methylated differentially expressed lncRNAs (DElncRNAs) and differentially expressed genes (DEGs) were identified, followed by GO biological process and KEGG pathway functional enrichment analyses. Expression levels of several DElncRNAs and DEGs were evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for validation. Results: m6A levels and METTL3 expression levels were significantly lower in the brain tissues of the NTD mouse model than in controls. By integrating MeRIP-seq and RNA-seq data, 13 differentially m6A-methylated DElncRNAs and 170 differentially m6A-methylated DEGs were identified. They were significantly enriched in the Hippo signaling pathway and mannose-type O-glycan biosynthesis. The qRT-PCR results confirmed the decreased expression levels of lncRNAs, such as Mir100hg, Gm19265, Gm10544, and Malat1, and genes, such as Zfp236, Erc2, and Hmg20a, in the NTD group. Conclusion: METTL3-mediated m6A modifications may be involved in NTD development. In particular, decreased expression levels of Mir100hg, Gm19265, Gm10544, Malat1, Zfp236, Erc2, and Hmg20a may contribute to the development of NTD.

Evaluation of specific heavy metal levels of pregnant women complicated by neural tube defects

Aim: The etiology of neural tube defect (NTD) is still not clear enough. In our study, we aimed to evaluate plasma heavy metal levels of pregnant women with NTD and to determine whether there is a relationship between heavy metal levels and NTD severity.Material and Methods: TThis study was conducted in Adiyaman University, Department of Gynaecology and Obstetrics. The study included 38 pregnant women with NTD and 42 pregnant women with healthy infants. Pregnant women who have NTD were divided into two groups as NTD Type 1 and NTD Type 2 according to the anomaly type. Levels of heavy metals such as Mercury (Hg), Cadmium (Cd), Cobalt (Co), Lead (Pb), Manganese (Mn) and Arsenic (As) were compared between groups.Results: Plasma Hg, Co, Cd and Pb levels were higher in NTD group than control group. (p values, respectively; p 0.001, p = 0.001, p 0.001, p 0.001). As and Mn levels were not statistically different between the two groups (p values; p = .519, p = .819, respectively). In the NTD group, Hg was found to be higher in NTD Type 1 than NTD Type 2 (p 0.001).Conclusion: It is obvious that some histomorphological changes are formed in the cardinal ligaments of patients with uterine prolapse due to pressure on the uterus. We believe that the increase in the number of extravasated erythrocytes and the thickness of the vascular wall and peripheral nerve should be supported by further studies.

Complex Nature of Neural Tube Defects: A Regional Experience

Objective: The underlying gene-environment interaction of fetal neural tube defects is affected by several factors including geography, ethnicity and time. Local features of fetal neural tube defects were described.Study Design: A prospective cohort study of 48 fetal neural tube defects in a single tertiary medical center at the northwestern region of Turkey (2013-2015) was done via ultrasound, magnetic resonance imaging (MRI), conventional karyotyping, maternal methylenetetrahydrofolate reductase c.677C>T (rs1801133) single-nucleotide polymorphism and maternal serum levels of folic acid, vitamin B12 and zinc. For comparison of means, a Student’s T-Test was used.Results: The prevalence of neural tube defects was 11.4 per 10000 births (48/42000) in northwestern Turkey. The defects on the cranium (n=23; 47.9%) and spine (n=25; 52.1%) were ultrasonographically detected. MRI did not give additional benefit over the ultrasonography. The ratio of associated anomalies in neural tube defect group was 25%. Two fetal neural tube defects with Down syndrome were remarkable. The rate of homozygous methylenetetrahydrofolate reductase c.677C > T SNPs among the mothers of neural tube defect fetuses (n=20) was 15%. Comparing with gestationally matched healthy pregnancies, although maternal BMIs and periconceptional folate intake of neural tube defect group were significantly different, maternal serum folic acid, vitamin B12 and zinc levels were similar.Conclusion: The northwestern region appeared to be a relatively low prevalence area of Turkey for fetal neural tube defects. Any association with maternal serum folic acid, vitamin B12 and zinc levels could not be shown in this region.

Establishment and evaluation of enzyme-linked immunosorbent assay for measuring human IgM autoantibody to folate receptor

To establish the method of enzyme-linked immunosorbent assay (ELISA) for measuring human IgM autoantibody to folate receptor. Folate receptor was extracted and purified from the healthy woman placenta. The protein was coated on 96-well plates with a concentration of 5 ng/Μl. Goat monoclonal antibody was used for detecting antibody. Pooled plasma from healthy donors was used to plot the standard curve and the IgM concentration of pooled plasma was defined as 1. We set up an ELISA procedure to measure human IgM autoantibody to folate receptor. The sensitivity, precision, and stability of the method were evaluated. Further, the folate receptor and bovine folate-binding protein were used as the antigen, respectively, to determine the autoantibody levels in 24 healthy individuals and 20 individuals once gave birth to baby with neural tube defects. The measuring range of the method was from 6.25 × 10⁻⁴ to 8.00 × 10⁻². The lowest IgM level that can be detected was 3.12 × 10⁻⁴. The inter-assay coefficients of variations for samples with high, medium, and low IgM levels were 6.61%,3.50%, and 5.12%, respectively. The intra-assay coefficients of variations were 4.54%, 5.49%, and 5.44%, respectively. The stability test results were considered within acceptable limits. The data from folate receptor-ELISA was significantly higher than that from bovine folate binding protein-ELISA, both in the healthy group (t=-11.9, P<0.001) and in the neural tube defect group (t = 7.35, P<0.001). The folate receptor-ELISA method for measuring human IgM autoantibody to folate receptor was successfully established. The method is sensitive, repeatable, and stable.

Evaluation of the levels of folate, vitamin B12, homocysteine and fluoride in the parents and the affected neonates with neural tube defect and their matched controls

The aim of this study is to evaluate the folate, vitamin B12, fluoride and homocysteine levels in newborns with neural tube defect (NTD) and their parents. The study included 35 neonates with NTD and their parents, 31 neonates with congenital anomalies other than NTD formed control 1, 24 neonates with no anomalies, with the highest birth order and normal siblings formed control 2. These groups matched for socio-economic and nutritional status. Demographic, antenatal history, parental habits, folate (RBC, whole blood and serum), serum vitamin B12 and homocysteine levels were estimated using chemiluminescence technology. Chi-square test was used to assess association between factors and the outcome. One-way ANOVA was used to compare means in the three groups. To determine the risk factors for NTD, odds ratios (95% CI) was computed using bivariate and multivariate logistic regression analysis (STATA 9.0). No difference was found between NTD group and 'control 1' group. The fathers in NTD group had significantly lower folate and vitamin B12 and a higher homocysteine, in comparison to 'control 2' group (i.e. with normal babies). The babies with NTD had higher homocysteine while their mothers had significantly low folate levels in comparison to 'control 2' mothers. Low RBC folate, low serum vitamin B12 and high plasma homocysteine in both the parents had an association with NTD. Multivariate logistic regression revealed high homocysteine of father as the only independent significant risk factor [OR(95% CI):2.6(2.6, 226)] for NTD and also for other anomalies. NTD (and other congenital anomalies) may not only be due to nutritional deficiency in the mothers but also due to more intricate gene-nutrient interaction defects in the affected families, probably some abnormal folate-homocysteine metabolism. These defects seem to be affect the fathers more severely and in all likelihood, get transmitted to the babies from either or both the parents. The emergence of father's serum homocysteine levels as an independent risk factor for NTD and also other congenital anomalies calls for further studies to evaluate if this can be taken as a marker for congenital anomalies in the fetus during antenatal screening.

Severe Fetal Hydrocephalus with and without Neural Tube Defect: A Comparative Study

Objective: To describe the main perinatal and 1-year outcomes in babies with a prenatal ultrasonographic diagnosis of severe hydrocephalus according to the presence or absence of a neural tube defect (NTD) in a country where abortion is illegal. Method: The study population consisted of cases referred to and delivered at Hospital de Clínicas de Porto Alegre, diagnosed between January 1993 and December 2001. The diagnosis of severe hydrocephalus was based on a lateral ventricular atrium diameter ≧15 mm in at least one hemisphere. Results: Sixty cases were ascertained: 28 with NTD (group 1) and 32 without NTD (group 2). The groups were similar in terms of maternal and child variables at birth and hospitalization days during the 1st year of life. The mortality (including intrauterine deaths and deaths of babies with malformations incompatible with life that characterize a very poor prognosis) until 1 year of age was 36% in group 1 and 59% in group 2 (p = 0.077). The rate of cardiac malformations was higher in the group without NTD (p = 0.015). The length of hospital stay after birth (1st admission) was significantly higher in the group with NTD (p = 0.007). Conclusions: The morbidity was higher in the group with NTD, possibly due to the higher number of surgical interventions in the central nervous system. However, the mortality was higher in the group without NTD, possibly due to the presence of other associated malformations, especially congenital heart disease. Further studies should focus on neurological function and quality of life of the children and their families at the end of the 1st year and after 2 or 6 years of age.

Correlation of elevated leptin levels in amniotic fluid and maternal serum in neural tube defects

Objective To measure maternal serum and amniotic fluid leptin concentrations in pregnant women diagnosed antenatally as having fetuses with a neural tube defect in the second trimester. Methods Twenty pregnant women who had fetuses with a neural tube defect detected on ultrasonography (neural tube defect group) in the second trimester and 20 women who had abnormal triple screens indicating an increased risk for Down syndrome but had healthy fetuses (control group) were enrolled in the study. Amniotic fluid was obtained by amniocentesis, and maternal serum samples were taken simultaneously. Results The mean leptin levels in amniotic fluid ( P < .001) and maternal serum ( P < .05) of patients who had fetuses with a neural tube defect were found to be significantly higher than control group levels. The mean leptin levels in maternal serum of both groups were also higher than leptin levels in amniotic fluid ( P < .05 for the neural tube defect group and P < .001 for the control group). Although there were significant correlations between maternal weight, weight gain, body mass index at the time of amniocentesis, and maternal serum leptin concentrations in both groups, a significant correlation between leptin concentrations in maternal serum and amniotic fluid was found only in the neural tube defect group ( P < .05). Conclusion We found significantly higher leptin levels in both amniotic fluid and maternal serum of patients who had fetuses with a neural tube defect. We suggest that the main source of leptin in amniotic fluid of pregnant women who had fetuses with a neural tube defect is the leakage into amniotic fluid from cerebrospinal fluid. The increase of maternal serum leptin concentrations has been attributed to the transportation of amniotic fluid leptin to the maternal circulation.

Reproductive History in Mothers of Children with Neural Tube Defects

The reproductive history of 100 women with at least 1 child with a neural tube defect (NTD) has been studied. The data analyzed correspond to the period previous to their first visit to a genetic counseling service. A total of 204 pregnancies resulted in 205 outcomes. Of the 100 sibships, 14 (14%) had more than 1 affected member. The pregnancy was shorter than 28 weeks in 56/205 (27%) of the total outcomes. Of 104 evaluable previous outcomes, 34 corresponded to short pregnancies, positioned before an affected (23/60, 38%), a healthy (2/18, 11%), or an undiagnosed product (9/26, 35%). Short pregnancies subsequent to affected outcomes were also increased. The inter-gestational interval varied according to diagnosis: it was longer in the affected group than in the healthy one (0.1 > p > 0.05) and the subsequent intervals were shorter for the affected group (p < 0.05). An increased number of abortions adjacent to affected offspring and a changing fertility pattern, depending on the product diagnosis, point to an environmental etiological component in this high-risk NTD group of mothers.

Nutritional patterns of mothers of children with neural tube defects in Newfoundland

In an exploratory study of the genetic epidemiology of neural tube defects in Newfoundland, we studied mothers who had given birth to a child with a neural tube defect (NTD) with respect to their nutrition, as well as various other factors. The frequency of NTD in the area studied was 3.5/1,000 births and has not decreased recently, as it has in some other parts of the world. Twenty-five mothers of children with NTD and a comparison group (CG), matched for age and neighbourhood, completed 3 day dietary records. The NTD group consisted of all mothers who had given birth to an NTD child within the previous 3.5 years in the chosen area. The CG mothers were ascertained through the local public health nurse who chose the nearest unaffected child born in the same time period as the NTD probands. NTD mothers were younger, heavier, and of lower socioeconomic status than were CG mothers. CG group women consumed more vitamin supplements during the periconceptional period (P < 0.05) and consumed more dairy and cereal products, fruits and vegetables (other than potatoes), and fewer sweets than did NTD mothers. Sixty-four percent of NTD mothers had folacin intakes below the recommended level (168 mg) compared to 27% of CG mothers (P < 0.01). These findings support previous evidence that poor maternal nutrition, and low dietary folate in particular, increase the chance of having a child with an NTD, and emphasize the need for supplementary folate in the diet of women of childbearing age in areas where the frequency of NTDs is high.

Potato steroidal alkaloids and neural tube defects: serum concentrations fail to demonstrate a causal relation.

Spoiled potatoes and, in particular, steroidal alkaloids have been proposed as an aetiological factor in the pathogenesis of neural tube defect (NTD). The present study involves the measurement of potato (solanum) steroidal alkaloid concentrations in serum by radioimmunoassay. Serum solanidine and total potato alkaloid concentrations were measured in two groups of women: one group pregnant with a fetus, subsequently shown to be affected by a NTD, the other with a healthy fetus. Serum alkaloid concentrations were, contrary to expectations, lower in the NTD group. They lend no weight therefore to the theory that potato alkaloids are responsible for NTD, but are consistent with the opinion that some water-soluble vitamins lessen the risk.