Syndromes and Disorders Associated with Omphalocele (III): Single Gene Disorders, Neural Tube Defects, Diaphragmatic Defects and Others

Multifaced roles of the long non-coding RNA DRAIC in cancer progression

Long non-coding RNAs (lncRNA) are functional RNAs, with over 200 nucleotides in length and lacking protein-coding potential. Studies have indicated that lncRNAs are important gene regulators under physiological conditions. Aberrant lncRNA expression is associated with the initiation and progression of various diseases, including cancers. High-throughput transcriptome analyses have revealed thousands of lncRNAs as putative tumor suppressors or promoters in various cancers, but the detailed molecular mechanisms of each lncRNA remain unclear. Downregulated RNA In Cancer, inhibitor of cell invasion and migration (DRAIC) (also known as LOC145837 and RP11-279F6.1) is a lncRNA that inhibits or promotes cancer progression with several modes of action. DRAIC was originally identified as a tumor-suppressive lncRNA in prostate adenocarcinoma. Subsequent studies also revealed that it has an anti-tumor role in glioblastoma, triple-negative breast cancer, and stomach adenocarcinoma. However, DRAIC exhibits oncogenic functions in other malignancies, such as lung adenocarcinoma and esophageal carcinoma, indicating its highly context-dependent effects on cancer progression and clinical outcomes. DRAIC and its associated pathways regulate various biological processes, including proliferation, invasion, metastasis, autophagy, and neuroendocrine function. This review introduces the multifaceted roles of DRAIC, particularly in cancer progression, and discusses its biological significance and clinical implications.

Embryology of the Abdominal Wall and Associated Malformations—A Review

In humans, the incidence of congenital defects of the intraembryonic celom and its associated structures has increased over recent decades. Surgical treatment of abdominal and diaphragmatic malformations resulting in congenital hernia requires deep knowledge of ventral body closure and the separation of the primary body cavities during embryogenesis. The correct development of both structures requires the coordinated and fine-tuned synergy of different anlagen, including a set of molecules governing those processes. They have mainly been investigated in a range of vertebrate species (e.g., mouse, birds, and fish), but studies of embryogenesis in humans are rather rare because samples are seldom available. Therefore, we have to deal with a large body of conflicting data concerning the formation of the abdominal wall and the etiology of diaphragmatic defects. This review summarizes the current state of knowledge and focuses on the histological and molecular events leading to the establishment of the abdominal and thoracic cavities in several vertebrate species. In chronological order, we start with the onset of gastrulation, continue with the establishment of the three-dimensional body shape, and end with the partition of body cavities. We also discuss well-known human etiologies.

Exomphalos with intestinal fistulation: Case series and systematic review for clinical characterization, management and embryopathogenesis

INTRODUCTION

Exomphalos with intestinal fistulation (EIF) is a rare variant of exomphalos with intestine opening to the surface of an intact sac, and may result in a diagnostic challenge. We report 3 new cases and conducted a systematic review of the literature, to characterize its association with the type of exomphalos and vitellointestinal duct (VI) as well as to evaluate its management and outcomes.

METHODS

A literature search from PubMed using keywords pertaining to exomphalos and fistulation was used to identify all unique cases reported between 1950 and 2020, in addition to the case series reported here, to establish the clinical presentation, histological findings, management and outcomes.

RESULTS

We found a total of 28 cases of EIF, of which 25 had been reported in 70 years from 19 reports. There was a male predominance (4-to-1 ratio). The majority presented as an exomphalos minor (n = 23, 82%) with a prolapsing patent VI duct (n = 16, 57%), most had evidence of Meckel's diverticulum (n = 25, 89%). All but one case were managed by fistula excision with or without ileal resection and anastomosis, followed by primary closure of the abdominal wall defect. All patients, except one with Trisomy 13 who received only palliative care, underwent surgery. Post-operative complications occurred in 7 patients (25%). Congenital anomalies were present in 12 (43%) and none had Beckwith-Wiedemann syndrome. Mortality occurred in 4 patients (14%) between 3 and 17 days. One EIF with exomphalos major failed early conservative treatment due to sac disintegration and sepsis, requiring staged closure, but had a good outcome.

DISCUSSION

EIF is a rare entity usually associated with exomphalos minor and vitelline duct involvement. EIF presentation is variable but primary surgery is the mainstay of treatment with generally good outcomes. Common features of EIF suggest a different embryopathogenesis to other forms of exomphalos.

Ductus venosus reversed flow in omphalocele: Could it be a prognostic factor for long-term neurological impairment?

Omphalocele (exomphalos) represents one of the most frequent congenital abdominal wall defects. It presents as a defect of inconstant size and is located on the midline, at the base of the umbilical cord, the skin, fascia, and abdominal muscles being absent at this level. Omphaloceles are classified as liver-containing or non-liver-containing, the latter containing primarily bowel loops. We present the case of a 37-year-old pregnant woman with an early diagnosis of liver-containing omphalocele associating ductus venosus reversed flow, with the aim to highlight the importance of the first-trimester morphology scan and to develop a pilot study regarding the neurological development of infants after surgical repair of giant omphaloceles. The particularity of this case consists of a fetus with a positive diagnosis of a giant liver-containing omphalocele but with a small abdominal wall defect during the first-trimester morphology scan at 13 weeks and 3 days of gestation which associated ductus venosus reversed flow, presenting a normal karyotype postabortum. With a small defect, we can speculate the risk of strangling besides the mechanical traction exercised on the ductus venosus generating fetal distress, specifically fetal hypoxia at an early gestational age. In conclusion, the main issue, in this case, was if the fetal omphalocele and ductus venosus reversed flow indicated fetal hypoxia, what was the obstruction effect on the oxygenated blood pathway caused by the abdominal defect, and which were the long-term effects on infants with this complex pathology with an unknown outcome.

Does meconium contaminated amniotic fluid affect intestinal wall thickness and functional outcome in patients with anterior abdominal wall defects?

BACKGROUND

Gastroschisis (GS) and omphalocele (OC) are congenital abdominal wall defects, the main difference between is the direct exposure of intestinal loops in amniotic fluid in children with a GS. This leads to a reduced primary closure rate and a higher number of intraoperative abnormalities and post-operative complications.

AIMS AND OBJECTIVES

We analysed abdominal wall defect patients over an 11-year period, aiming to assess the influence of meconium-contaminated amniotic fluid. This study has different objectives to show the consequence of functional outcome of abdominal wall defects (AWD) children in reliance to colour of amniotic fluid, to assess the effect of reduced bowel exposure time to meconium contaminated amniotic fluid on edematous inflammatory thickening of the bowel loops, to show an positively influence in the number of primary AWD closures, to demonstrate a reduced incidence of post-natal complications and to verify a better outcome of OC children because of failing exposure to amniotic fluid.

METHODS

A retrospective, observational case-control design was used to compare GS (n = 36) and OC (n = 18) children. Physical data, colour of amniotic fluid, pre- and perinatal problems, operative complications and surgical technique, post-operative complications, duration of intensive care unit (ICU) stay, mechanical ventilation, parenteral nutrition, commencement of oral feeding and total hospital stay were collected. Data were analysed with descriptive methods, t-test and non-parametric tests such as Wilcoxon and Kruskal-Wallis were performed in addition to the analysis of variance, including post hoc testing accepting a confidence interval of 95% (P < 0.05) by using IBM SPSS software, version 23 (IBM, Illinois, USA).

RESULTS

Rate of meconium-contaminated amniotic fluid is significantly higher in GS compared to OC (P < 0.001), delivery problems such as congenital infections are also significantly higher (P < 0.001), this yields in significantly more bowel loops anomalies and problems during surgery (P < 0.036) but had no significant influence on primary abdominal wall closures rate (P = 0.523). The post-surgical outcome of OC was significantly better as compared to GS. Within the GS, those with swollen intestines had significantly longer ICU stays (P = 0.045) due to extended mechanical ventilation (P = 0.007), parenteral nutrition (P = 0.011) and delayed initiation of oral feeding (P < 0.001. Same results were found for the duration of ICU stay (P = 0.008), mechanical ventilation (P = 0.006), parenteral nutrition (P = 0.011) and delayed initiation of oral feeding (P < 0.001) in secondary closures as compared to primary abdominal wall closures in the GS group.

CONCLUSIONS

Worsen functional short-term outcome of GS children was directly addicted to meconium contamination of amniotic fluid due to swollen intestines and because of this more post-surgical problem including significantly extended hospital stays were observed.

Genetic counseling for fetal gastrointestinal anomalies

PURPOSE OF REVIEW

Congenital gastrointestinal anomalies are common findings with relatively established methods of treatment. However, the genetic cause of how these defects occur and how that may impact a child's lifelong care is less established. Genetic testing has improved significantly in recent years, yet reviews documenting prenatal genetic counseling and testing guidelines have not been comprehensively updated.

RECENT FINDINGS

Congenital anomalies of the foregut, such as tracheoesophageal fistula carry a high association with genetic disorders, both in isolation and syndromic forms. Duodenal atresia remains highly associated with Trisomy 21 but is not enriched in other genetic conditions. Disorders of the midgut, such as omphalocele often have a genetic cause and may require both cytogenetic and panel testing to obtain a diagnosis. The etiologic basis of hindgut malformations remain largely unknown, though imperforate anus as well as Hirschprung's disease have been associated with many micro deletion syndromes as well as in association with other birth defects as part of larger syndromes.

SUMMARY

Prenatal diagnostic genetic testing through amniocentesis or chorionic villus sampling can be offered to every patient who wants to learn genetic information about their fetus. Cytogenetic testing, such as microarray is a first tier test to assess cause for these conditions and can provide meaningful answers. When a gastrointestinal anomaly is identified in association with an additionally affected organ system next-generation sequencing and defect-specific genetic testing panels can be necessary to understand cause as well as prognosis to best prepare families for the medical management that lies ahead.

Gestational Outcomes of Pregnancies with Prenatally Detected Gastroschisis and Omphalocele

Objective: To evaluate and compare the outcomes of pregnancies with prenatally detected gastroschisis and omphalocele. Materials and Methods: We retrospectively evaluated prenatally detected gastroschisis and omphalocele cases. Cases were compared in terms of maternal demographic and clinical characteristics as well as pregnancy and neonatal outcomes. Results: This study consisted of 17 gastroschisis and 30 omphalocele cases. Only one case with gastroschisis was terminated due to additional severe limb deformities. Seventeen out of 30 cases of omphalocele were terminated for various reasons (56.7%). All patients with gastroschisis had surgical repair, while 8 out of 13 omphalocele cases had surgery. One patient with an omphalocele died after surgery due to sepsis. Six cases of gastroschisis also died in the neonatal period due to various reasons (6/16, 37.5%). Conclusion: Additional genetic disorders are more frequent in those with omphalocele cases, and they are more frequently terminated during gestation that the gastroschisis fetuses.

Sequence variants identification at the KCNQ1OT1:TSS differentially Methylated region in isolated omphalocele cases

Background

Omphalocele is a congenital midline ventral body wall defect that can exist as isolated malformation or as part of a syndrome. It can be considered one of the major and most frequent clinical manifestation of Beckwith-Wiedemann Syndrome (BWS) in case of loss of methylation at KCNQ1OT1: Transcription Star Site-Differentially Methylated Region (TSS-DMR) or in presence of CDKN1C mutations. The isolated form of the omphalocele accounts approximately for about the 14% of the total cases and its molecular etiology has never been fully elucidated.

Methods

Given the tight relationship with BWS, we hypothesized that the isolated form of the omphalocele could belong to the heterogeneous spectrum of the BWS associated features, representing an endophenotype with a clear genetic connection. We therefore investigated genetic and epigenetic changes affecting BWS imprinted locus at 11p15.5 imprinted region, focusing in particular on the KCNQ1OT1:TSS DMR.

Results

We studied 21 cases of isolated omphalocele detected during pregnancy or at birth and identified the following rare maternally inherited variants: i) the non-coding variant G > A at nucleotide 687 (NR_002728.3) at KCNQ1OT1:TSS-DMR, which alters the methylation pattern of the imprinted allele, in one patient; ii) the deletion c.624-629delGGCCCC at exon 1 of CDKN1C, with unknown clinical significance, in two unrelated cases.

Conclusions

Taken together, these findings suggest that KCNQ1OT1:TSS-DMR could be a susceptibility locus for the isolated omphalocele.

Electronic supplementary material

The online version of this article (10.1186/s12881-017-0470-z) contains supplementary material, which is available to authorized users.

Fetal abdominal wall defects

The most common fetal abdominal wall defects are gastroschisis and omphalocele, both with a prevalence of about three in 10,000 births. Prenatal ultrasound has a high sensitivity for these abnormalities already at the time of the first-trimester nuchal scan. Major unrelated defects are associated with gastroschisis in about 10% of cases, whereas omphalocele is associated with chromosomal or genetic abnormalities in a much higher proportion of cases. Challenges in management of gastroschisis are related to the prevention of late intrauterine death, and the prediction and treatment of complex forms. With omphalocele, the main difficulty is the exclusion of associated conditions, not all diagnosed prenatally. An outline of the postnatal treatment of abdominal wall defects is given. Other rarer forms of abdominal wall defects are pentalogy of Cantrell, omphalocele, bladder exstrophy, imperforate anus, spina bifida complex, prune-belly syndrome, body stalk anomaly, and bladder and cloacal exstrophy; they deserve multidisciplinary counselling and management.

Genome-wide linkage and copy number variation analysis reveals 710 kb duplication on chromosome 1p31.3 responsible for autosomal dominant omphalocele

BACKGROUND

Omphalocele is a congenital birth defect characterised by the presence of internal organs located outside of the ventral abdominal wall. The purpose of this study was to identify the underlying genetic mechanisms of a large autosomal dominant Caucasian family with omphalocele.

METHODS AND FINDINGS

A genetic linkage study was conducted in a large family with an autosomal dominant transmission of an omphalocele using a genome-wide single nucleotide polymorphism (SNP) array. The analysis revealed significant evidence of linkage (non-parametric NPL = 6.93, p=0.0001; parametric logarithm of odds (LOD) = 2.70 under a fully penetrant dominant model) at chromosome band 1p31.3. Haplotype analysis narrowed the locus to a 2.74 Mb region between markers rs2886770 (63014807 bp) and rs1343981 (65757349 bp). Molecular characterisation of this interval using array comparative genomic hybridisation followed by quantitative microsphere hybridisation analysis revealed a 710 kb duplication located at 63.5-64.2 Mb. All affected individuals who had an omphalocele and shared the haplotype were positive for this duplicated region, while the duplication was absent from all normal individuals of this family. Multipoint linkage analysis using the duplication as a marker yielded a maximum LOD score of 3.2 at 1p31.3 under a dominant model. The 710 kb duplication at 1p31.3 band contains seven known genes including FOXD3, ALG6, ITGB3BP, KIAA1799, DLEU2L, PGM1, and the proximal portion of ROR1. Importantly, this duplication is absent from the database of genomic variants.

CONCLUSIONS

The present study suggests that development of an omphalocele in this family is controlled by overexpression of one or more genes in the duplicated region. To the authors' knowledge, this is the first reported association of an inherited omphalocele condition with a chromosomal rearrangement.

Omphalocele and alveolar capillary dysplasia: a new association

OBJECTIVE

First report of an infant with coexistent omphalocele and alveolar capillary dysplasia.

DESIGN

Descriptive case report.

SETTING

Neonatal intensive care unit of a tertiary care children's hospital.

PATIENT

We describe a term infant with omphalocele and respiratory insufficiency attributable to pulmonary hypertension. The patient was placed on extracorporeal membrane oxygenation, but the pulmonary hypertension persisted. After 10 days on extracorporeal membrane oxygenation, a lung biopsy was performed. It showed alveolar capillary dysplasia. Because of the lethal prognosis, extracorporeal membrane oxygenation was withdrawn and the patient expired.

CONCLUSIONS

This is the first description of an association between omphalocele and alveolar capillary dysplasia. In newborns with omphalocele who have severe respiratory insufficiency and pulmonary hypertension, alveolar capillary dysplasia should be considered.

Mutational analysis of two boys with the severe perinatally lethal Melnick-Needles syndrome

Melnick-Needles syndrome (MNS) (OMIM 309350) is a rare, X-linked dominant condition, caused by mutations in the filamin A gene (FLNA, on Xq28). In females, the syndrome presents with bone dysplasia and characteristic facial changes. Affected males may show two different phenotypes. One is similar to the female phenotype and is seen in children born to unaffected mothers and suggesting new mutations. Alternatively, males born to affected mothers have an embryonic or perinatally lethal disorder. It has been claimed that MNS constitutes part of a spectrum including frontometaphyseal dysplasia, otopalatodigital syndrome type 1 (OPD1) and otopalatodigital syndrome type 2 (OPD2). These conditions are produced by different mutations in the filamin A gene (FLNA). MNS is caused by three different mutations in FLNA exon 22, to date detected only in females. We describe the clinical manifestations and present the results of FLNA exon 22 mutations screening in two boys with the perinatally lethal form of MNS and their affected mothers. In order to obtain DNA amplification from paraffin-embedded tissues, we designed a new method based on hemi-nested PCR. One of the children (and his mother) had a previously undescribed mutation produced by a double SNP in the positions 3776 and 3777 of the gene and leading to an amino acid substitution (NP_001447:p.[Gly1176Asp]). The second child (and his mother) had an already known mutation (NP_001447.2:p[.Ser1199Leu]). This is the first report confirming the presence FLNA mutations in boys with the perinatally lethal phenotype of MNS. (