[Gastroschisis and omphalocele: Incidence and outcome]

INTRODUCTION

Gastroschisis and omphalocele are the most common congenital abdominal wall defects. The main purpose of this study was to investigate the incidence, other associated anomalies and the course of these diseases in Iceland.

MATERIAL AND METHODS

The study was retrospective. The population was all newborns who were admitted to the NICU of Children's Hospital Iceland due to gastroschisis or omphalocele in 1991-2020. Furthermore, all fetuses diagnosed prenatally or post mortem where the pregnancy ended in spontaneous or induced abortion, were included.

RESULTS

During the study period, 54 infants were born with gastroschisis and five with omphalocele. The incidence of gastroschisis was 4.11 and omphalocele 0,38/10,000 births. There was no significant change in the incidence of the diseases during the study period. In addition, five fetuses were diagnosed with gastroschisis and 31 with omphalocele where the pregnancy was terminated. In addition to gastroschisis in the live born infants and fetuses the most common associated anomalies were in the gastrointestinal or urinary tract but in infants and fetuses with omphalocele anomalies of the cardiac, central nervous or skeletal systems were the most common. Sixteen fetuses diagnosed with omphalocele had trisomy 18. Mothers aged 16-20 were more likely to give birth to an infant with gastroschisis than older mothers (p< 0.001). Primary closure was successful in 86% of the infants. Those reached full feedings significantly earlier and were discharged earlier. Overall survival rate was 95%. Three children were still receiving parenteral nutrition at discharge due to short bowel syndrome.

CONCLUSIONS

The incidence of gastroschisis in Iceland is in accordance with studies in other countries but but the incidence of omphalocele is lower, which can be partly explained by spontaneous or induced abortions. Other anomalies associated with omphalocele are more severe than those associated with gastroschisis. Primary closure was associated with more benign course. Children with gastroschisis may need prolonged parenteral nutrition due to shortening of their intestines.

Searching for new signals for susceptibility to umbilical hernia through genome-wide association analysis in three pig breeds

Umbilical hernia (UH) is a prevalent congenital disorder in pigs, resulting in considerable economic losses and severe animal welfare issues. In the present study, we conducted a genome-wide association study (GWAS) using the GeneSeek 50K Chip in 2777 pigs (Duroc, n = 1267; Landrace, n = 696; and Yorkshire, n = 814) to explore the candidate genes underlying the risk of umbilical hernia in pigs. After quality control analyses, 2748 animals and 48 524 single nucleotide polymorphisms (SNPs) were retained for subsequent GWAS analysis using the FarmCPU model. The heritability of umbilical hernias was estimated to 0.51 ± 0.04, indicating a reasonable basis for investigating genetic markers associated with this disorder. We identified 54 SNPs and 517 candidate genes that showed significant associations with susceptibility to umbilical hernia across the combined population of the three pig breeds. Gene enrichment analyses highlighted several crucial pathways for platelet degranulation, inflammatory mediator regulation of TRP channels and ion transport. These findings provide further insights into the underlying genetic architecture of umbilical hernias in pigs.

Altered Transcript Levels of MMP13 and VIT Genes in the Muscle and Connective Tissue of Pigs with Umbilical Hernia

Umbilical hernia (UH) and inguinal hernia (IH) are among the most common defects in pigs, affecting their welfare and resulting in economic losses. In this study, we aimed to verify the association of previously reported differences in transcript levels of the ACAN, COL6A5, MMP13, and VIT genes with the occurrence of UH and IH. We examined mRNA levels in muscle and connective tissue from 68 animals-34 affected by UH and 34 controls. In a second cohort, we examined inguinal channel samples from 46 pigs (in four groups). We determined DNA methylation levels in muscle tissue for the UH and control animals. The transcript level of MMP13 changed in the UH cases, being upregulated and downregulated in muscle and connective tissue, respectively, and the VIT gene also showed an increased muscular mRNA level. The transcript of the ACAN gene significantly decreased in old pigs with IH. We further observed an increased DNA methylation level for one CpG site within the MMP13 gene in UH individuals. We conclude that these alterations in gene mRNA levels in the UH animals depend on the tissue and can sometimes be a consequence of, not a cause of, the affected phenotype.

Ultrasonographic characteristics, genetic features, and maternal and fetal outcomes in fetuses with omphalocele in China: a single tertiary center study

BACKGROUND

Patients with omphalocele, a midline abdominal wall defect at the umbilical cord base, have a low survival rate. However, the long-term outcomes of fetuses with prenatally diagnosed omphalocele have scarcely been studied. Therefore, we investigated the ultrasonographic features, genetic characteristics, and maternal and fetal outcomes of fetuses with omphalocele and provided a reference for the perinatal management of such cases.

METHODS

A total of 120 pregnant females with fetal omphalocele were diagnosed using prenatal ultrasonography at the Fujian Provincial Maternity and Child Health Hospital from January 2015 to March 2022. Amniotic fluid or cord blood samples were drawn at different gestational weeks for routine karyotype analysis, chromosomal microarray analysis (CMA) detection, and whole exome sequencing (WES). The maternal and fetal outcomes were followed up.

RESULTS

Among the 120 fetuses, 27 were diagnosed with isolated omphalocele and 93 with nonisolated omphalocele using prenatal ultrasonography. Cardiac anomalies were the most observed cause in 17 fetuses. Routine karyotyping and CMA were performed on 35 patients, and chromosomal abnormalities were observed in five patients, trisomy 18 in three, trisomy 13 in one, and chromosome 8-11 translocation in one patient; all were non-isolated omphalocele cases. Six nonisolated cases had normal CMA results and conventional karyotype tests, and further WES examination revealed one pathogenic variant and two suspected pathogenic variants. Of the 120 fetuses, 112 were successfully followed up. Eighty of the 112 patients requested pregnancy termination. Seven of the cases died in utero. A 72% 1-year survival rate was observed from the successful 25 live births.

CONCLUSION

The prognosis of fetuses with nonisolated omphalocele varies greatly, and individualized analysis should be performed to determine fetal retention carefully. Routine karyotyping with CMA testing should be provided for fetuses with omphalocele. WES is an option if karyotype and CMA tests are normal. If the fetal karyotype is normal and no associated abnormalities are observed, fetuses with omphalocele could have a high survival rate, and most will have a good prognosis.

Prenatal genetic diagnosis of omphalocele by karyotyping, chromosomal microarray analysis and exome sequencing

OBJECTIVES

The aim of this study is to share our experience in the prenatal diagnosis of omphalocele by karyotyping, chromosomal microarray analysis (CMA) and whole exome sequencing (WES).

METHODS

In this retrospective study, 81 cases of omphalocele were identified from 2015 to 2020. Associated anomalies and prenatal diagnosis based on karyotyping, CMA and WES were analysed.

RESULTS

Fifty-eight (71.6%) of the 81 foetuses had other ultrasound anomalies. Giant omphalocele was present in 11 cases (13.6%) and small omphalocele was present in 70 cases (86.4%). Chromosomal abnormalities were found in 24 foetuses (29.6%, 24/81), the most common of which were trisomy 18 (58.8%, 11/24) and trisomy 13 (29.2%, 7/24). Compared to isolated omphalocele, non-isolated omphalocele was accompanied by an increased prevalence of chromosomal abnormalities (4.3% (1/23) vs. 39.7% (23/58), χ2 = 8.226, p = .004). All chromosomal abnormalities were found in small omphalocele. Aside from aneuploidy, CMA showed one pathogenic copy number variants (CNVs) for a detection rate of 1.2%, one variants of unknown significance (VOUS) and one instance of loss of heterozygosity (LOH). WES was performed on 3 non-isolated cases, and one was found to have pathogenic variants.

CONCLUSIONS

The most common genetic cause of omphalocele is aneuploidy and the prevalence of chromosomal abnormalities is increased with non-isolated and small omphalocele. CMA and WES can be useful for providing further genetic information to assist in prenatal counselling and pregnancy management.

A joint analysis using exome and transcriptome data identifiescandidate polymorphisms and genes involved with umbilical hernia in pigs

BACKGROUND

Umbilical Hernia (UH) is characterized by the passage of part of the intestine through the umbilical canal forming the herniary sac. There are several potential causes that can lead to the umbilical hernia such as bacterial infections, management conditions and genetic factors. Since the genetic components involved with UH are poorly understood, this study aimed to identify polymorphisms and genes associated with the manifestation of umbilical hernia in pigs using exome and transcriptome sequencing in a case and control design.

RESULTS

In the exome sequencing, 119 variants located in 58 genes were identified differing between normal and UH-affected pigs, and in the umbilical ring transcriptome, 46 variants were identified, located in 27 genes. Comparing the two methodologies, we obtained 34 concordant variants between the exome and transcriptome analyses, which were located in 17 genes, distributed in 64 biological processes (BP). Among the BP involved with UH it is possible to highlight cell adhesion, cell junction regulation, embryonic morphogenesis, ion transport, muscle contraction, within others.

CONCLUSIONS

We have generated the first exome sequencing related to normal and umbilical hernia-affected pigs, which allowed us to identify several variants possibly involved with this disorder. Many of those variants present in the DNA were confirmed with the RNA-Seq results. The combination of both exome and transcriptome sequencing approaches allowed us to better understand the complex molecular mechanisms underlying UH in pigs and possibly in other mammals, including humans. Some variants found in genes and other regulatory regions are highlighted as strong candidates to the development of UH in pigs and should be further investigated.

Transcriptome analysis identifies genes involved with the development of umbilical hernias in pigs

Umbilical hernia (UH) is one of the most frequent defects affecting pig production, however, it also affects humans and other mammals. UH is characterized as an abnormal protrusion of the abdominal contents to the umbilical region, causing pain, discomfort and reduced performance in pigs. Some genomic regions associated to UH have already been identified, however, no study involving RNA sequencing was performed when umbilical tissue is considered. Therefore, here, we have sequenced the umbilical ring transcriptome of five normal and five UH-affected pigs to uncover genes and pathways involved with UH development. A total of 13,216 transcripts were expressed in the umbilical ring tissue. From those, 230 genes were differentially expressed (DE) between normal and UH-affected pigs (FDR <0.05), being 145 downregulated and 85 upregulated in the affected compared to the normal pigs. A total of 68 significant biological processes were identified and the most relevant were extracellular matrix, immune system, anatomical development, cell adhesion, membrane components, receptor activation, calcium binding and immune synapse. The results pointed out ACAN, MMPs, COLs, EPYC, VIT, CCBE1 and LGALS3 as strong candidates to trigger umbilical hernias in pigs since they act in the extracellular matrix remodeling and in the production, integrity and resistance of the collagen. We have generated the first transcriptome of the pig umbilical ring tissue, which allowed the identification of genes that had not yet been related to umbilical hernias in pigs. Nevertheless, further studies are needed to identify the causal mutations, SNPs and CNVs in these genes to improve our understanding of the mechanisms of gene regulation.

Kagami-Ogata syndrome: an important differential diagnosis to Beckwith-Wiedemann syndrome

We report the case of a fetus with sonographic characteristics of Beckwith-Wiedemann syndrome (BWS). A 30-year-old gravida 2 para 1 was referred to our fetal medicine unit with an omphalocele. Fetal macrosomia, organomegaly, and polyhydramnios but no macroglossia were detected and BWS was suspected. Genetic testing for BWS did not confirm the suspected diagnosis as the karyotype was normal. Symptomatic polyhydramnios led to repeated amnioreductions. At 35 + 5 weeks of gestation, a female neonate of 3660 g was delivered with APGAR scores of 6/7/8, after 1/5/10 min, respectively. The abnormal shape of the thorax, facial dysmorphism, need for ventilation, and generalized muscular hypotonia led to the suspicion of Kagami-Ogata syndrome (KOS), which was confirmed by genetic testing. KOS in our patient was caused by a large deletion in the MEG3-region on chromosome 14q32 affecting the maternal allele. In this report, we highlight the notion that when sonographic signs suggestive of BWS such as macrosomia, polyhydramnios, and omphalocele are present and genetic testing does not confirm the suspected diagnosis, KOS should be tested for.

SUSCEPTIBILITY LOCI FOR UMBILICAL HERNIA IN SWINE DETECTED BY GENOME-WIDE ASSOCIATION

Umbilical hernia (UH) is a complex disorder caused by both genetic and environmental factors. UH brings animal welfare problems and severe economic loss to the pig industry. Until now, the genetic basis of UH is poorly understood. The high-density 60K porcine SNP array enables the rapid application of genome-wide association study (GWAS) to identify genetic loci for phenotypic traits at genome wide scale in pigs. The objective of this research was to identify susceptibility loci for swine umbilical hernia using the GWAS approach. We genotyped 478 piglets from 142 families representing three Western commercial breeds with the Illumina PorcineSNP60 BeadChip. Then significant SNPs were detected by GWAS using ROADTRIPS (Robust Association-Detection Test for Related Individuals with Population Substructure) software base on a Bonferroni corrected threshold (P = 1.67E-06) or suggestive threshold (P = 3.34E-05) and false discovery rate (FDR = 0.05). After quality control, 29,924 qualified SNPs and 472 piglets were used for GWAS. Two suggestive loci predisposing to pig UH were identified at 44.25MB on SSC2 (rs81358018, P = 3.34E-06, FDR = 0.049933) and at 45.90MB on SSC17 (rs81479278, P = 3.30E-06, FDR = 0.049933) in Duroc population, respectively. And no SNP was detected to be associated with pig UH at significant level in neither Landrace nor Large White population. Furthermore, we carried out a meta-analysis in the combined pure-breed population containing all the 472 piglets. rs81479278 (P = 1.16E-06, FDR = 0.022475) was identified to associate with pig UH at genome-wide significant level. SRC was characterized as plausible candidate gene for susceptibility to pig UH according to its genomic position and biological functions. To our knowledge, this study gives the first description of GWAS identifying susceptibility loci for umbilical hernia in pigs. Our findings provide deeper insights to the genetic architecture of umbilical hernia in pigs.

Fetal abdominal wall defects: six years experience at a tertiary center

The authors' aim was to detect the associated anomalies and their effect on the management of the fetuses with omphalocele and gastroschisis. Between the period of 2007-2013, the data of fetuses with abdominal wall defects were analyzed. Chromosomal abnormalities and associated morphologic anomalies diagnosed by ultrasonography and autopsy were evaluated. Of the. 61 fetuses, ten (20.4%) omphalocele cases and nine (75%) gastroschisis cases were isolated. Chromosomal abnormalities were found in seven fetuses with omphalocele cases. All fetuses with abnormal karyotypes had multiple additional anomalies. Termination rate was 65.3% for omphalocele group versus none in the gastroschisis group. To give better counseling about the prognosis and outcome of the fetuses with abdominal wall defects, detection of additional anomalies as well as type of the defect are essential tools even if the karyotype is normal.

Eya1 and Eya2 gene expression is down-regulated during somitic myogenesis in the cadmium-induced omphalocele chick model

PURPOSE

The molecular mechanisms underlying omphalocele are still largely unknown. Recently, established cadmium (Cd)-induced omphalocele chick model has been used to investigate the pathogenesis of omphalocele. The earliest histologic changes in this model has been observed in somites 4 hours posttreatment, leading us to hypothesize that disruption of migration of somite-derived cells ventrally may cause omphalocele phenotype. Eyes absent (Eya) genes are expressed in the somite (dermomyotome) and play a key role in somitic myogenesis. We designed this study to investigate the hypothesis that Eya1 and Eya2 gene expression is down-regulated during the critical period of early embryogenesis in the Cd-induced omphalocele chick model.

METHODS

After 60 hours of incubation, chicks were exposed to either chick saline or Cd and divided into control and Cd (n = 24 for each group). Chicks were then harvested 1 hour, 4 hours, and 8 hours posttreatment. Real-time quantitative polymerase chain reaction was performed to evaluate gene expression levels of Eya1 and Eya2 in the chick embryo, and they were statistically analyzed. Immunofluorescence confocal microscopy was also performed to evaluate protein expression and distribution pattern of Eya1 and Eya2.

RESULTS

At 4 hours posttreatment, the relative messenger RNA expression levels of Eya1 and Eya2 were significantly down-regulated in the Cd group compared with controls (P < .05). The intensity of Eya1 and Eya2 immunofluorescence was also markedly diminished at 4 hours in the Cd-treated embryos, whereas in control embryos, strong intensity of immunofluorescence of them was expressed in the dermomyotomal cells.

CONCLUSION

Down-regulation of Eya genes during the critical period of early embryogenesis may contribute to omphalocele phenotype in the Cd chick model, interfering with migration of embryonic body wall ventrally.

Presenilin genes are downregulated during somitogenesis in the cadmium-induced omphalocele chick model

PURPOSE

Although the precise pathogenesis of ventral body wall (VBW) defects is not clearly understood, it has recently postulated that disruption of somite development during early embryogenesis may cause failure of proper VBW formation. The administration of cadmium (Cd) after 60 h of incubation induces omphalocele spectrum in the chick embryo. Previous studies have shown that one of the earliest histological changes seen in this model is abnormal cell death in the somite, occurring at 4 h post treatment (4H). However, the molecular mechanism by which Cd acts in this critical period of embryogenesis still remains unclear. Presenilins are expressed in somites and play an important role in vertebrate development, including somitogenesis and thus VBW formation. We designed this study to test the hypothesis that gene expression levels of presenilin 1 (PSEN1) and presenilin 2 (PSEN2) are downregulated during the critical period of early embryogenesis in the Cd-induced omphalocele in the chick model.

METHODS

After 60 h of incubation, chick embryos were exposed to either saline or 50 μM cadmium and divided into two groups: control and Cd (n = 8 at each time point for each group). Real-time RT-PCR was performed to evaluate the relative mRNA expression levels of PSEN1 and PSEN2 in the Cd-induced omphalocele chick model. Differences between two groups at each time point were analysed statistically and the significance was accepted at p < 0.05. Immunofluorescence confocal microscopy was performed to evaluate the protein expression/distribution of presenilins in the somite of chick embryo.

RESULTS

The relative mRNA expression levels of PSEN1 and PSEN2 were significantly downregulated in the Cd group at 4H compared with controls (p < 0.005) (Table). However, there were no significant differences at the other time points. At 4H, immunofluorescence of presenilins (green) was markedly diminished in the Cd-treated embryos, whereas strong immunofluorescence of them was seen in the somite (dermomyotome) in controls (Fig. 1). 1 Immunofluorescence Confocal Microscopy for PSEN1 and PSEN2 in the dermomyotome of the somite in the trunk level of chick embryo 4H post treatment. Intensity of PSEN1 immunofluorescence (green) was markedly diminished in Cd-treated embryos, whereas strong PSEN1 expression was seen in the dermomyotome in controls. PSEN2 immunofluorescence was also decreased in the Cd-treated embryos, whereas strong PSEN2 immunofluorescence (green) was observed predominantly in the dermomyotome in controls. Immunofluorescence in orange is DNA counter staining by DAPI CONCLUSION: We provide evidence, for the first time, that gene expression of presenilins is downregulated during the narrow window of very early embryogenesis in the Cd chick model. Decreased expression of presenilins may contribute to omphalocele phenotype in Cd chick model, by disrupting somite development.

Altered PITX2 and LEF1 gene expression in the cadmium-induced omphalocele in the chick model

PURPOSE

Although, recent studies have suggested that disruption of somitogenesis may be involved in ventral body wall (VBW) defects; the molecular mechanisms of VBW defects remain unclear. In the chick embryo, the administration of cadmium (Cd) induces VBW defects similar to the human omphalocele. In this model, the earliest histological change in the somite occurs commencing at 4 h post-Cd treatment (4 h). PITX2 is expressed in somites, and PITX2 mutants have been shown to display VBW defects. PITX2 interacts with lymphoid enhancer factor-1 (LEF1) to regulate somite myogenesis. We designed this study to investigate the hypothesis that PITX2 and LEF1 genes are downregulated during the critical period of early embryogenesis in the Cd-induced omphalocele chick model.

MATERIALS AND METHODS

Chick embryos were exposed to Cd or saline after 60 h incubation and harvested at 1, 4, and 8 h posttreatment. Chicks were then divided into two groups: control (n = 24), and Cd (n = 24). RT-PCR was performed and analyzed statistically (significant difference was accepted at p < 0.05). Immunohistochemistry was also performed to evaluate expression/distribution of those proteins.

RESULTS

The mRNA expression levels of PITX2 and LEF1 at 4 h were significantly decreased in the Cd group compared with controls, whereas there were no differences at the other time points. Immunoreactivity of those proteins at 4 h was also markedly decreased in somites in the Cd-treated embryos compared with controls.

CONCLUSIONS

Downregulation of PITX2 and LEF1 genes may interfere with ventral body wall formation in Cd chick model causing omphalocele by disrupting somite myogenesis.

The changing face of gastroschisis and omphalocele in southeast Georgia

OBJECTIVE

To document trends in the clinical characteristics of gastroschisis and omphalocele in southeast Georgia, USA, from 1994 to 2002.

METHODS

All babies with an abdominal wall defect in a 19-county region were referred to one Perinatal Center for genetic counseling, level II ultrasound scans, pregnancy follow-up and delivery. Karyotyping was offered for omphalocele, advanced maternal age, family history predisposing to aneuploidy, and gastroschisis with an additional anomaly.

RESULTS

There were 64 patients, 34 with gastroschisis and 30 with omphalocele. From 1994 to 2002, the birth prevalence of gastroschisis was 1:3600 and omphalocele 1:3400, but from 2000 to 2002, gastroschisis increased to 1:1667, while omphalocele increased to only 1:2709. Gender distribution was different: for gastroschisis the M:F ratio was 1:2.1; for omphalocele the ratio was 1.7:1. In the patients with omphalocele, 90% had an amniocentesis and 9/27 were aneuploid: five had trisomy 18, three had trisomy 13 and one had trisomy 21. Seventy-six per cent of the patients with omphalocele had associated anomalies, but only 17.6% of those with gastroschisis. Mothers whose babies had gastroschisis showed a trend to progressively younger age, while no such trend was observed among mothers whose babies had omphalocele.

CONCLUSION

The birth prevalence of abdominal wall defects in general is increasing, but more notably for gastroschisis. Maternal age continues to decrease for gastroschisis. In the study population, gender distribution showed a statistically significant variation between the defects.

Prenatal diagnosis of a case with anencephaly-omphalocele-unilateral absent radial ray

We report here a female fetus with anencephaly, omphalocele and unilateral radial aplasia. The combination of two of these three malformations were reported in a number of patients diagnosed as Gershoni-Barush syndrome, ORR phenotype, VATER association, Schisis association, OEIS complex, Schinzel phocomelia syndrome and Acalvaria but they have not been reported all together in the same patient up to date. We hypothesize that, some or all these syndromes given above may be related etiologically.

Downregulation of ROCK-I and ROCK-II gene expression in the cadmium-induced ventral body wall defect chick model

PURPOSE

In the chick embryo, administration of the heavy metal cadmium (Cd) after 60 h incubation induces the ventral body wall defect (VBW) with similarities to the human omphalocele. Rho-associated coiled-coil-containing protein kinase (ROCK) I and ROCK-II mediate signalling from Rho to the actin cytoskeleton in the Wnt non-canonical pathway. ROCK-I knockout (KO), ROCK-II KO, and ROCK-I/ROCK-II double heterozygous mice have been shown to cause failure of closure of the VBW. The exact mechanism by which Cd acts in the Wnt signalling pathway still remains unclear. We designed this study to test the hypothesis, that the gene expression levels of ROCK-I and ROCK-II are downregulated during the critical period of embryogenesis in the Cd-induced VBW defect chick model.

METHODS

Chick embryos were harvested 1 h (1H), 4 h (4H), and 8 h (8H) after treatment of cadmium and divided into two groups: control (n = 8 at each time point), and Cd (n = 8 at each time point). Real-time RT-PCR was performed to evaluate the relative mRNA levels of ROCK-I and ROCK-II expression in the Cd-induced VBW defect chick model. Differences between the two groups at each time point were tested by using Mann-Whitney's U test and statistical significance was accepted at P < 0.05.

RESULTS

The relative mRNA levels of ROCK-I and ROCK-II at 4H were significantly decreased in Cd group compared to controls (P < 0.01 and P < 0.001, respectively). The expression levels of ROCK-I and ROCK-II at 1H and 8H were not significantly different between Cd group and controls.

CONCLUSIONS

Our results provide evidence, for the first time, that the gene expression levels of ROCK-I and ROCK-II are significantly downregulated at 4 h after treatment of Cd in the VBW defect model of chick embryo. We speculate that the downregulation of ROCK-I and ROCK-II gene expressions during this narrow window of embryogenesis may cause VBW defect by disrupting Wnt non-canonical pathway.

Outcome of antenatally diagnosed abdominal wall defects

OBJECTIVE

To examine the natural history and detailed outcome of antenatally diagnosed abdominal wall defects.

METHODS

This was a retrospective review of the antenatal reports, pediatric surgery records and subsequent follow-up information of all cases of omphalocele and gastroschisis diagnosed in a 10-year period in our tertiary referral center.

RESULTS

There were 109 cases of abdominal wall defects, including omphalocele in 67 cases and gastroschisis in 42 cases. Of the 67 cases of omphalocele there were 26 (39%) with chromosomal abnormalities and 22 (33%) underwent termination of pregnancy, mainly for associated structural abnormalities. Of the ongoing 19 cases there were five (26%) in-utero deaths, 12 (63%) survivors and two (11%) neonatal deaths, both associated with prematurity. Excluding chromosomal abnormalities, the survival rate in isolated omphalocele was 7/16 (44%) whilst it was 5/25 (20%) in those with associated abnormalities. Gastroschisis was isolated in 40 (95%) cases. Among these 40 isolated cases there were two (5%) terminations. Of the 38 ongoing cases, there were two (5%) in-utero deaths, and 36 (95%) live births. Four of the 36 liveborn infants (11%) died in the postoperative period owing to complications of small bowel atresia.

CONCLUSIONS

Although only 18% of infants with antenatally diagnosed omphalocele were alive in the neonatal period, postoperative morbidity was low. The majority (90%) of fetuses with antenatally diagnosed gastroschisis survived to delivery, but the mortality in affected newborns was 11%.

Deficient Alk3-mediated BMP signaling causes prenatal omphalocele-like defect

BMP signaling plays important roles in many embryonic developmental processes. Alk3 is one of two BMP type I receptors that transduces BMP signal from the cell surface into cell. Conventional knockout of Alk3 resulted in early embryonic lethality around E7.5-E9.5. In this study, we have generated embryonic mesoderm-specific Alk3 conditional knockout by crossing Dermo1-Cre and floxed Alk3 mice. Abrogation of Alk3-mediated BMP signaling in this mouse resulted in severe defect of secondary ventral body wall formation, replicating the omphalocele phenotype in human. Our finding suggests that Alk3 plays an essential role in the formation of embryonic ventral abdominal wall, and abrogation of BMP signaling activity due to gene mutations in its signaling components could be one of the underlying causes of omphalocele at birth.

Chromosomal Abnormalities Associated With Omphalocele

Fetuses with omphalocele have an increased risk for chromosomal abnormalities. The risk varies with maternal age, gestational age at diagnosis, association with umbilical cord cysts, complexity of associated anomalies, and the contents of omphalocele. There is considerable evidence that genetics contributes to the etiology of omphalocele. This article provides an overview of chromosomal abnormalities associated with omphalocele and a comprehensive review of associated full aneuploidy such as trisomy 18, trisomy 13, triploidy, trisomy 21, 45,X, 47,XXY, and 47,XXX, partial aneuploidy such as dup (3q), dup (11p), inv (11), dup (1q), del (1q), dup (4q), dup (5p), dup (6q), del (9p), dup (15q), dup(17q), Pallister-Killian syndrome with mosaic tetrasomy 12p and Miller-Dieker lissencephaly syndrome with deletion of 17p13.3, and uniparental disomy (UPD) such as UPD 11 and UPD 14. Omphalocele is a prominent marker for chromosomal abnormalities. Perinatal identification of omphalocele should alert chromosomal abnormalities and familial unbalanced translocations, and prompt thorough cytogenetic investigations and genetic counseling.

Omphalocele in an infant with Cornelia de Lange syndrome

Cornelia de Lange syndrome is a genetic condition characterized by a very distinctive facial appearance, hirsutism, limb anomalies, growth retardation and developmental delay. Most cases occur sporadically as the result of a new autosomal dominant mutation, but there are also reports of parent to child transmission. Associated clinical features that are less frequent are quite well known in this very well described genetic syndrome. Omphalocele does not appear to ever have been reported to be an associated feature. We report, for the first time, an omphalocele in a molecularly confirmed case of Cornelia de Lange syndrome.

Chromosome 11 segmental paternal isodisomy in amniocytes from two fetuses with omphalocoele: new highlights on phenotype-genotype correlations in Beckwith-Wiedemann syndrome

BACKGROUND

The phenotypic variability in Beckwith-Wiedemann syndrome (BWS) reflects the genetic heterogeneity of the mechanism which by default leads to the deregulation of genes located at 11p15.5. Genotype-phenotype correlation studies have demonstrated an association between omphalocoele and CDKN1C/p57 mutations or hypermethylation. Paternal uniparental disomy 11 (pUPD11) has been described only in the mosaic condition with both uniparental and biparental cell lines, and no association with omphalocoele has been pointed out.

METHODS

Two cases are presented here, in which a paternal segmental UPD11 was detected by molecular investigation of amniotic fluid cell cultures after the presence of apparently isolated omphalocoele was revealed in the fetuses by ultrasound scan. Further studies were performed on additional autoptic feto-placental tissues to characterise the distribution of the uniparental cell line and to unmask any biparental lineage in order to document in more detail the as yet unreported association between omphalocoele and pUPD11.

RESULTS

Results on the UPD distribution profile showed that the abdominal organs have a predominant uniparental constitution. This condition could mimic the effect of CDKN1C/p57 inactivation, causing the omphalocoele.

CONCLUSION

New genotype-phenotype correlations emerge from the investigated cases, suggesting that molecular analysis be extended to all cases with fetal omphalocoele in order to establish the incidence of pUPD11 in complete BWS and in monosymptomatic/mild forms.

Current outcome of antenatally diagnosed exomphalos: an 11 year review

PURPOSE

The aim of this study was to determine the outcome of antenatally diagnosed exomphalos.

METHODS

The database of a tertiary referral Fetal Medicine Centre was searched for all cases of antenatally diagnosed exomphalos between January 1991 and December 2002. Patients, general practitioners, and hospitals were contacted for outcome details.

RESULTS

In total, 445 cases of exomphalos were identified. In 250 (56%) cases, the fetal karyotype was abnormal (group A), in 135 (30%) cases, the karyotype was normal (group B), and in 60 (14%) cases, karyotyping was declined (group C). In group A, there were 248 (99%) terminations of pregnancy (TOP) or fetal deaths and 2 live births. In group B, 74 (54%) fetuses had other structural anomalies; 82 (61%) pregnancies resulted in TOP or fetal death, 42 (31%) in live births, and 11 (8%) were lost to follow-up. In group C, 38 (63%) fetuses had other structural anomalies; 41 (69%) pregnancies resulted in TOP or fetal death, 11 (18%) in live births, and 8 (13%) were lost to follow-up. Of the 55 live births, 11 died preoperatively and 44 had surgery. There were no postoperative deaths.

CONCLUSIONS

Less than 10% of the antenatal diagnostic workload reached operative repair. In our unit, these babies are a highly selected group, which is a factor in the high postoperative survival.

Shprintzen–Goldberg omphalocele syndrome: A new patient with an expanded phenotype

Shprintzen and Goldberg [1979] described a new autosomal dominant syndrome characterized by omphalocele, scoliosis, pharyngeal and laryngeal hypoplasia, mild dysmorphic face, and learning disabilities. This condition was described in a father and three daughters, one of whom died in infancy, probably of airway narrowing. Here, we report on a second observation of this syndrome in a 6-year-old patient. In our case, omphalocele, imperforate anus, and feeding impairment were the main clinical problems in the neonatal period. Scoliosis appeared during the fourth year of age. The facial appearance is similar to the original patients and additional clinical findings are described which expand the phenotypic spectrum.

Characteristics and outcome of 90 cases of fetal omphalocele

OBJECTIVE

The aim of this study was to describe the outcome of a case series of fetuses with omphalocele.

METHODS

Ninety fetuses with omphalocele at the National Center for Fetal Medicine (NCFM) between January 1985 and January 2004 were followed from the time of prenatal diagnosis. Follow-up times ranged from 6 months to 17 years. Omphaloceles were subdivided into epigastric, central and hypogastric types based on their location on the abdominal wall.

RESULTS

There were 58 central and 32 epigastric omphaloceles. Abnormal karyotype was found in 40/58 (69%) of the central and in 4/32 (12.5%) of the epigastric omphaloceles. Trisomy 18 was the most frequent abnormality associated with omphalocele. Among the fetuses with normal karyotype, 89% of the central and 71% of the epigastric cases had other anomalies. 38 (66%) of the fetuses with central omphalocele were terminated and 12 (21%) died during pregnancy or after delivery. 11 (34%) of the fetuses with epigastric omphalocele were terminated and eight (25%) died during pregnancy or after delivery. Of the 90 cases followed from the time of diagnosis there were 21 (23%) survivals. Of eight survivals with central omphalocele, only two were considered healthy while six had other anomalies and/or substantially impaired development. Of 13 survivals with epigastric omphalocele, six were considered healthy and seven had other anomalies and/or substantial impairment.

CONCLUSIONS

Fetal central and epigastric omphaloceles may be different entities: central omphaloceles are more strongly associated with abnormal karyotype (69%) than are epigastric omphaloceles (12.5%). The outcome of fetuses with omphalocele is poor irrespective of the type of omphalocele, with only eight of the 90 (9%) being alive and healthy at present. The results emphasize the importance of identifying both those fetuses with a potentially good prognosis and favorable outcome and those which are likely to have a fatal outcome.

Definitive surgical management of antenatally diagnosed exomphalos

BACKGROUND/PURPOSE

The management of exomphalos is controversial with many centers in the United Kingdom and elsewhere advocating a conservative nonsurgical approach for the larger examples. Nevertheless, this approach is not without problems or complication. The aim of the study was to ascertain the outcome of all infants with an antenatally diagnosed exomphalos treated recently at our institution using a policy of aggressive abdominal wall closure.

METHODS

This is a retrospective review of all infants with exomphalos treated from January 1995 to September 2002.

RESULTS

There were 35 infants, all of whom underwent surgery. These were separated into 3 groups: group A (all exomphalos minor) underwent primary closure (n = 11), group B (exomphalos major) underwent primary closure (n = 13), and group C (exomphalos major) underwent staged closure involving a silo (n = 11). Infants in group C had a lower birth weight (P = .05) and were less mature (P = .06). They required longer periods of ventilation (P < .001), a longer hospital stay (P = .001), and a longer period to achieve full enteral feeds (P < .001). Overall survival was 34 (97%) of 35 infants. One premature infant who was born with a ruptured exomphalos sac (birth weight, 862 g) died of nonsurgical complications (sepsis and respiratory failure) early after the creation of a silo.

CONCLUSIONS

An aggressive surgical approach in infants with exomphalos is a safe option resulting in effective abdominal wall closure. This requires a skilled multidisciplinary approach and possibly greater resources than other options.

Finally, a sense of closure? Animal models of human ventral body wall defects

Malformations concerning the ventral body wall constitute one of the leading categories of human birth defects and are present in about one out of every 2000 live births. Although the occurrence of these defects is relatively common, few detailed experimental studies exist on the development and closure of the ventral body wall in mouse and human. This field is further complicated by the array of theories on the pathogenesis of body wall defects and the likelihood that there is no single cause for these abnormalities. In this review, we summarize what is known concerning the mechanisms of normal ventral body wall closure in humans and mice. We then outline the theories that have been proposed concerning human body wall closure abnormalities and examine the growing number of mouse mutations that impact normal ventral body wall closure. Finally, we speculate how studies in animal models such as mouse and Drosophila are beginning to provide a much-needed mechanistic framework with which to identify and characterize the genes and tissues required for this vital aspect of human embryogenesis.

Folate-related genes and omphalocele

Women who take folic acid in the periconceptional period greatly reduce their chances of having a child with a neural tube defect (NTD). Using multivitamins may also reduce the risk of having a child with an omphalocele. In this study, we tested single nucleotide polymorphisms in folate-related enzyme genes for association with omphalocele. Polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methylenetetrahydrofolate dehydrogenase (MTHFD1), the reduced folate carrier (SLC19A1), and transcobalamin II (TCN2) were examined in 25 children with euploid omphalocele and 59 matched controls. Omphalocele cases were significantly more likely to carry the T allele of MTHFR 677C-->T, a known risk factor for NTDs (odds ratio 3.50, 95% confidence interval 1.07-11.47, P=0.035). The MTHFD1 R653Q, SLC19A1 R27H, and TCN2 P259R polymorphisms showed no significant association with omphalocele. In this small study, the thermolabile variant of MTHFR, 677C-->T, was associated with an increased risk for omphalocele. This variant causes reduced enzyme activity, thus suggesting a mechanism by which multivitamins with folic acid might prevent omphalocele. Additional investigation is required.

A syndrome characterized by contractures and pterygia of upper body associated with umbilical hernia, short stature, and distinctive face in an Arabic family

A large Moslem Arabic family from the North of Israel is presented in which nine individuals are affected with short stature (5th centile and below), variable pterygium of neck or short neck with limited range of motion, pterygium of elbows, short palms, and brachydactyly. Other abnormalities of the fingers include syndactyly, camptodactyly, and/or hypermobility of the small joints. The face typically appeared long and myopathic. Ptosis was present with downslanting palpebral fissures, facial movements were reduced and the midface was flat. Umbilical hernia was present together with hypoplasia of the skin in the periumbilical area. The lower body region was unaffected in this family. The family is characterized by multiple consanguineous marriages, and the pedigree is consistent with autosomal recessive inheritance. The phenotype seems to be distinct from other multiple pterygium syndromes because the lower limbs are spared, and the umbilical hernia with hypoplastic skin has not been described previously.

Bovine umbilical hernia maps to the centromeric end ofBos taurusautosome 8

Twelve bull calves were produced by mating elite Israeli cows to "Glenhapton Enhancer", a Canadian Holstein bull. The frequency of umbilical hernia (UH) in the progeny of the sons ranged from 1 to 21%, consistent with the hypothesis that Enhancer is the carrier of major dominant or codominant gene with partial penetrance for UH. Five sons of Enhancer produced progeny with >10% frequency of UH including sire 3259, whereas progeny of three sons had <3% UH. A total of 116 grand-progeny of Enhancer, all progeny of 3259, were genotyped for 59 microsatellites spanning the 29 bovine autosomes. Of these offspring, 41 were affected. Significant differences in paternal allele frequencies between the affected and unaffected progeny groups were found for marker BMS1591 on bovine chromosome 8 (BTA8). The UH-associated paternal allele originated from Enhancer. The chromosomal segment associated with UH was more precisely mapped between UWCA47, on the centromeric end of BTA8 and RM321, 12 cM from the centromere. A maximum LOD score of 3.84 was obtained 2.5 cM from the centromere with a support interval of 8 cM. Haplotype analysis of eight sons of Enhancer suggested that the UH gene is located in the centromeric end of BTA8 beyond ARO71/ARO72. Thus, by integrating the results from progeny of sire 3259 and sons of Enhancer the location of the UH gene was further refined to the BTA8 segment between ARO71/ARO72 and UWCA47.

[Anterior abdominal wall defects--retrospective analysis of fetuses diagnosed in the Department of Obstetrics & Gynecology of the Postgraduate Center of Medical Education between 1997 & 2002]

OBJECTIVES

Our objectives were to determine the risk of aneuploidy and anatomic anomalies in fetuses with different kinds of abdominal wall defects.

DESIGN

We retrospectively studied ultrasound reports of the fetuses with abdominal wall defects.

MATERIALS AND METHODS

We analyzed 108 cases diagnosed during the last five years in our center. All fetuses underwent a detailed ultrasonographic survey and in majority of cases (78.8%) antenatal karyotyping was performed. We also analyzed gestational age at the first examination.

RESULTS

35 cases presented gastroschisis, 60 omphalocele, 7 ectopia cordis and 6 limb-body wall complex. Associated anomalies were detected in 48.1% of all cases. It was 22.9% in gastroschisis group, 58.3% in omphalocele group, 42.9% in ectopia cordis group and in all fetuses with limb-body wall complex. Chromosomal abnormalities were present in 13% of all cases; in 2.9% of gastroschisis group, 20% of omphalocele group, 16.7% of limb-body wall complex group and none of the fetuses with ectopia cordis. The median gestational age at the first examination was 24 weeks.

CONCLUSIONS

In fetuses with abdominal wall defects detailed ultrasonographic survey and in majority of cases prenatal karyotyping should be done. Furthermore patients with fetus with such a defect should be diagnosed as early as possible in the referral center.

Mutations in PITX2 may contribute to cases of omphalocele and VATER-like syndromes

Omphalocele is a congenital anomaly with substantial morbidity. Rieger syndrome, an autosomal dominant disorder, is characterized by craniofacial abnormalities and abdominal wall defects. PITX2 mutations are etiologic in >40% of cases of Rieger syndrome. We demonstrate that the birth prevalence of omphalocele is significantly higher in Rieger syndrome than in the general population, with omphaloceles found in 0.03% in the Iowa newborn population and 4.3% of patients with Rieger syndrome. Our objective was to screen coding and conserved non-coding regions of PITX2 for mutations in 209 patients with omphalocele. We identified remarkable evolutionarily conserved regions by comparing the 3'UTR of Pitx2 in 13 vertebrate and 3 invertebrate species. No mutations changing the amino acid sequence were found within the omphalocele population. In one case of omphalocele with VATER-like additional anomalies, a three nucleotide deletion was found in the 3'UTR. This deletion was not seen in 1,186 controls. Also in the 3'UTR, we identified a single nucleotide polymorphism at a highly conserved residue. Our findings suggest additional studies of PITX2 conserved regions will be valuable. We also screened the omphalocele cases for mutations in exon 5 of the gene FLNA. Mutations in FLNA have been shown to cause a broad range of congenital malformations, including otopalatodigital syndrome type 2 in which a missense mutation occurring in exon 5 of FLNA results in omphalocele as part of the phenotype. We did not find any mutations in exon 5 of FLNA in 179 omphalocele cases studied.

Omphalocele and gastroschisis: An 18-year review study

PURPOSE

Using data from a single University Genetics Division practice, the authors sought to determine if gastroschisis is increasing in occurrence compared to omphalocele. Associated abnormalities were also examined. In addition, prenatal exposure to teratogens and other parameters were compared.

METHODS

All fetal and infant cases of omphalocele and gastroschisis seen in the University of South Florida Division of Genetics between January 2, 1982 and December 31, 1999 were retrieved through the database and analyzed through chart review.

RESULTS

There were 127 cases of omphalocele and 121 cases of gastroschisis. Ninety-three of the 127 probands with omphalocele had karyotype determinations and 20% were abnormal; for gastroschisis, 37 had cytogenetic studies and none had chromosomal anomalies. Seventy-six percent of the probands with omphalocele had associated abnormalities; twenty-three percent of the probands with gastroschisis, none of which were syndromic, had associated anomalies. The prematurity rate for omphalocele was 42% and mortality was 22%; for gastroschisis, the figures were 57% and 9%, respectively. There were no significant differences in teratogen exposure between the two groups. Familial cases of both defects occurred in < 4%, and the prevalence of dizygous twinning was increased in both groups. Mean maternal age was 21.8 years for the gastroschisis group, 27.2 years for the omphalocele group.

CONCLUSIONS

In this study, the number of cases of omphalocele and gastroschisis were similar, compared to the expected 3:2 ratio, suggesting an increase in the occurrence of gastroschisis. Cases with omphalocele had more syndromic and nonsyndromic anomalies, more chromosomal anomalies, a higher mortality rate, and older mothers.

Risk factors for umbilical hernia in Holstein heifers during the first two months after birth

OBJECTIVE

To determine risk factors associated with identification of an umbilical hernia during the first 2 months after birth in Holstein heifers.

DESIGN

Case-control study.

ANIMALS

322 Holstein heifers born in a single herd (45 with an umbilical hernia and 277 without).

PROCEDURE

Risk factors that were examined included sire, whether the dam had a history of umbilical hernia, milk yield, duration of gestation, whether the dam had a history of dystocia, whether the heifer had a twin, birth weight, total serum protein concentration, and whether the heifer had an umbilical infection. Logistic regression was used to analyze risk factors.

RESULTS

Heifers born to sires with > or = 3 progeny with an umbilical hernia were 2.31 times as likely to develop an umbilical hernia as were heifers born to sires with < or = 2 progeny with an umbilical hernia. Heifers with umbilical infection were 5.65 times as likely to develop an umbilical hernia as were heifers without umbilical infection.

CONCLUSIONS AND CLINICAL RELEVANCE

Sire and umbilical infection were associated with risk of an umbilical hernia during the first 2 months of life in Holstein heifers. Attributable proportion analysis indicated that the frequency of umbilical hernias in Holstein heifers with umbilical infection would have been reduced by 82% if umbilical infection had been prevented.

Omphalocele: clinical outcomes in cases with normal karyotypes

OBJECTIVE

This study was undertaken to examine neonatal outcomes in karyotypically normal cases of omphalocele with respect to mode of delivery, presence of associated anomalies, presence of extracorporeal liver, and method of abdominal wall closure.

STUDY DESIGN

We reviewed 36 cases of omphalocele with delivery at University of North Carolina Hospitals between 1988 and 2001. Elective terminations and pregnancies resulting in miscarriage before 20 weeks' gestation were excluded.

RESULTS

Perinatal mortality rate was 19%. Rate of composite neonatal morbidity was 25%. Associated major anomalies were present in 11 (31%) cases and were associated with increased neonatal mortality. Cesarean deliveries were performed in 21 (58%) cases and were not associated with increased primary closure rates or decreased neonatal morbidity and mortality. Extracorporeal liver was present in 27 (75%) cases and was associated with decreased rates of primary closure but did not affect neonatal outcome.

CONCLUSION

In cases of ongoing omphalocele, perinatal mortality rates are low in the absence of associated anomalies or genetic defects. Intracorporeal liver was not associated with increased rates of associated anomalies or was it associated with increased neonatal morbidity or mortality.

An infant with pentalogy of Cantrell and limb defects diagnosed prenatally

We present a case of pentalogy of Cantrell which was diagnosed prenatally on routine ultrasound examination. There were several associated limb defects. We discuss the differential diagnosis and conclude that our case probably had a variant form of this syndrome.

Omphalocele in trisomy 3q: further delineation of phenotype

We report a case of a patient with omphalocele, dysmorphic features, and mild developmental delay associated with a chromosomal aberration. Chromosome studies showed that the propositus carries a maternally derived unbalanced translocation der(4)t(3;4)(q27.3;q32.3), resulting in trisomy for region 3q27.3-->qter and monosomy for 4q32.3-->qter. Because the association between dup3q and omphalocele has been reported in several cases, we analyzed the data on 93 previously reported patients with partial trisomy of the long arm of chromosome 3 and compared the clinical features between the cases. The imbalance of chromosome 3 in the patient was further defined by fluorescence in situ hybridization (FISH) studies using bacterial artificial chromosome (BAC) clones. BAC clone RP11-171N2 was identified as a breakpoint-spanning clone in the patient and his mother. Based on our comparative analysis, we have delineated that the smallest region of overlap (SRO) associated with omphalocele is from BAC 171N2 to 3qter. We hypothesize that the SRO contains a gene(s) important in normal abdominal wall development and is of potential interest for further investigation.