Linkage localization of the thoraco-abdominal syndrome (TAS) gene to Xq25-26

PLS3 missense variants affecting the actin-binding domains cause X-linked congenital diaphragmatic hernia and body-wall defects

Congenital diaphragmatic hernia (CDH) is a relatively common and genetically heterogeneous structural birth defect associated with high mortality and morbidity. We describe eight unrelated families with an X-linked condition characterized by diaphragm defects, variable anterior body-wall anomalies, and/or facial dysmorphism. Using linkage analysis and exome or genome sequencing, we found that missense variants in plastin 3 (PLS3), a gene encoding an actin bundling protein, co-segregate with disease in all families. Loss-of-function variants in PLS3 have been previously associated with X-linked osteoporosis (MIM: 300910), so we used in silico protein modeling and a mouse model to address these seemingly disparate clinical phenotypes. The missense variants in individuals with CDH are located within the actin-binding domains of the protein but are not predicted to affect protein structure, whereas the variants in individuals with osteoporosis are predicted to result in loss of function. A mouse knockin model of a variant identified in one of the CDH-affected families, c.1497G>C (p.Trp499Cys), shows partial perinatal lethality and recapitulates the key findings of the human phenotype, including diaphragm and abdominal-wall defects. Both the mouse model and one adult human male with a CDH-associated PLS3 variant were observed to have increased rather than decreased bone mineral density. Together, these clinical and functional data in humans and mice reveal that specific missense variants affecting the actin-binding domains of PLS3 might have a gain-of-function effect and cause a Mendelian congenital disorder.

Case report: Investigation of genetic mutations in a case of schistosomus reflexus in a Holstein dairy cattle fetus in Korea

Schistosomus reflexus (SR) is one of the most common congenital anomalies found in cases of cattle dystocia; this disorder occurs mostly in cattle. Congenital anomalies such as SR are caused by various genetic and environmental factors, but no specific cause has been elucidated for SR. This study reports a case of SR in a Holstein dairy cattle fetus with congenital anomalies in Korea. Grossly, a distinct spine curvature was observed between the thoracic and lumbar vertebrae, accompanied by a consequential malformation from the sacrum to the occipital bone. Furthermore, the thoracic and abdominal organs were exposed. In computed tomography (CT) images, mild and severe kyphoscoliosis was observed in T1~11 and L1~6, respectively. Additionally, vertebral dysplasia was observed in S1~5 and Cd 1~5. To pinpoint the causal genes and mutations, we leveraged a custom 50K Hanwoo SNP-Chip and the Online Mendelian Inheritance in Animals (OMIA) database. As a result, we identified a nonsense mutation in apoptotic protease activating factor 1 (APAF1) within HH1 that was associated with a decrease in conception rate and an increase in abortion in Holstein dairy cattle. The genotype of the SR case was A/A, and most of the 1,142 normal Holstein dairy cattle tested as a control group had the genotype G/G. In addition, the A/A genotype did not exist in the control group. Based on the pathological, genetic, and radiological findings, the congenital abnormalities observed were diagnosed as SR.

Lateral thinking in syndromic congenital cardiovascular disease

Syndromic birth defects are rare diseases that can present with seemingly pleiotropic comorbidities. Prime examples are rare congenital heart and cardiovascular anomalies that can be accompanied by forelimb defects, kidney disorders and more. Whether such multi-organ defects share a developmental link remains a key question with relevance to the diagnosis, therapeutic intervention and long-term care of affected patients. The heart, endothelial and blood lineages develop together from the lateral plate mesoderm (LPM), which also harbors the progenitor cells for limb connective tissue, kidneys, mesothelia and smooth muscle. This developmental plasticity of the LPM, which founds on multi-lineage progenitor cells and shared transcription factor expression across different descendant lineages, has the potential to explain the seemingly disparate syndromic defects in rare congenital diseases. Combining patient genome-sequencing data with model organism studies has already provided a wealth of insights into complex LPM-associated birth defects, such as heart-hand syndromes. Here, we summarize developmental and known disease-causing mechanisms in early LPM patterning, address how defects in these processes drive multi-organ comorbidities, and outline how several cardiovascular and hematopoietic birth defects with complex comorbidities may be LPM-associated diseases. We also discuss strategies to integrate patient sequencing, data-aggregating resources and model organism studies to mechanistically decode congenital defects, including potentially LPM-associated orphan diseases. Eventually, linking complex congenital phenotypes to a common LPM origin provides a framework to discover developmental mechanisms and to anticipate comorbidities in congenital diseases affecting the cardiovascular system and beyond.

Complete and Incomplete Pentalogy of Cantrell

Pentalogy of Cantrell (PC) is a malformation characterized by defects in the ventral abdominal wall, lower sternum, diaphragmatic pericardium, anterior diaphragm associated with omphalocele, thoraco-abdominal ectopia cordis, diaphragmatic hernia, and intracardiac abnormalities. PC is stratified as complete or incomplete and we present both the complete and incomplete forms.

Pentalogy of Cantrell in Full Term Neonate

Pentalogy of Cantrell (PC) is an uncommon congenital disorder characterized by severe defects in the chest and abdomen, including abdominal visceral prolapsed via umbilical cord (omphalocele), defect in the lower part of the sternum, defect in the front of the diaphragm, defects in the anterior part of the pericardium, and the ectopiacordis. Here, we report a 2-hour-old girl, weighing 3,500 g, who was referred to Shahid Madani Hospital in Khorramabad due to the large omphalocele on her chest with pulsating mass above it. The baby was the first child of a 24-year-old mother who was born with an uncomplicated vaginal delivery. Very rare cases of PC are born as a term new-born.

Abrogation of TGF-beta signalling in TAGLN expressing cells recapitulates Pentalogy of Cantrell in the mouse

Pentalogy of Cantrell (PC) is a rare multi-organ congenital anomaly that impedes ventral body wall closure and results in diaphragmatic hernia, intra- and pericardial defects. The underlying cellular and molecular changes that lead to these severe developmental defects have remained unknown largely due to the lack of representative animal models. Here we provide in depth characterization of a mouse model with conditional ablation of TGFβRII in Transgelin (Tagln) expressing cells. We show that Tagln is transiently expressed in a variety of cells that participate in the embryonic development and patterning of ventral structures. Genetic ablation of TGFβRII in these cells leads to ventral midline closure defect, diaphragmatic hernia, dilated cardiac outflow tract and aberrant cardiac septation, providing a reliable model to study the morphological changes leading to PC. We show that myogenisis in the diaphragm is independent of TGFβ and the diaphragmatic hernia arises from fibroblast-specific migration defect. In the dorsal body wall Tagln expression is initiated after the closure process, revealing a remarkable difference between ventral and dorsal body walls development. Our study demonstrates the use of micro-CT scanning to obtain a 3-dimensional high-resolution overview of embryonic anomalies and provides the first mechanistic insight into the development of PC.

Class II pentalogy of Cantrell

Background

Pentalogy of Cantrell is a rare syndrome, first described by Cantrell and co-workers in 1958. The syndrome is characterized by the presence of five major congenital defects involving the diaphragm, abdominal wall, the diaphragmatic pericardium, lower sternum and various congenital intra-cardiac abnormalities. The syndrome has never been reported in Tanzania, although may have been reported from other African countries. Survival rate of the complete form of pentalogy of Cantrell is as low as 20%, but recent studies have reported normal growth achieved by 6 years of age where corrective surgeries were done; showing that surgical repair early in life is essential for survival.

Case presentation

The African baby residing in Tanzania was referred from a district hospital on the second day of life. She was noted to have a huge omphalocele and ectopia cordis covered by a thin membrane, with bowels visible through the membrane and the cardiac impulse visible just below the epigastrium. Despite the physical anomaly, she appeared to saturate well in room air and had stable vitals. Her chest X-ray revealed the absence of the lower segments of the sternum and echocardiography showed multiple intra-cardiac defects. Based on these findings, the diagnosis of pentalogy of Cantrell was reached. On her fifth day of life, the neonate was noted to have signs of cardiac failure characterized by easy fatigability and restlessness during feeding. Cardiac failure treatment was initiated and she was discharged on parents’ request on the second week of life. Due to inadequate facilities to undertake this complex corrective surgery, arrangements were being made to refer her abroad. In the meantime, her growth and development was satisfactory until the age of 9 months, when she ran out of the medications and succumbed to death. Her parents could no longer afford transport cost to attend the monthly clinic visits, where the infant was getting free medication refill.

Conclusions

The case reported here highlights that in resource limited settings; poor outcome in infants with complex congenital anomalies is a function of multiple factors. However, we believe that surgery would have averted mortality in this 9-month-old female infant. We hope to be able to manage these cases better in future following the recent establishment of cardiac surgery facilities at Muhimbili National Hospital.

Pentalogy of Cantrell; complete expression in a nine-month-old-boy

Pentalogy of Cantrell is a rare congenital malformation whose exact cause is not completely understood; it is characterized by defects in the anterior abdominal and thoracic walls consisting of omphalocoele, diaphragmatic defect, ectopia cordis, intracardiac defects and sternal clefts. The complex has variable clinical expression with complete and incomplete expressions reported. We, therefore, report a case of complete manifestation of the pentad in a 9-month-old boy.

Schistosoma reflexum in a cat: Insights into aetiopathogenesis

A foetal cat exhibiting multiple congenital malformations and meeting the criteria for being considered as a case of true schistosoma reflexum (SR) is described. SR in animals is briefly compared with relatively similar malformation entities in humans. Murine gene mutations producing severe ventral body wall defects associated with anomalies of internal organs and other structures are briefly reviewed. New insights into aetiopathogenic mechanisms possibly implicated in the development of SR are suggested. This is probably the first case of true SR reported in the cat.

Syndromes and Disorders Associated with Omphalocele (II): OEIS Complex and Pentalogy Of Cantrell

Omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex is characterized by a combination of omphalocele, exstrophy of the bladder, an imperforate anus, and spinal defects. Pentalogy of Cantrell is characterized by a combination of a midline supraumbilical abdominal wall defect, a defect of the lower sternum, a defect of the diaphragmatic pericardium, a deficiency of the anterior diaphragm, and congenital cardiac anomalies. This article provides a comprehensive review of OEIS complex and pentalogy of Cantrell, including the pathogenesis, prenatal diagnosis, differential diagnosis, and associated malformations. Omphalocele is an important sonographic marker for OEIS complex and pentalogy of Cantrell. Prenatal detection of an abdominal wall defect associated with multiple midline defects should alert one to the possibility of OEIS complex and pentalogy of Cantrell and prompt the genetic investigation and counseling of the disorders.

Schistosomus Reflexus Syndrome: A Heritable Defect in Ruminants

Schistosomus reflexus (SR) is a rare and fatal congenital disorder. Primarily observed in ruminants, its defining features include spinal inversion, exposure of the abdominal viscera because of a fissure of the ventral abdominal wall, limb ankylosis, positioning of the limbs adjacent to the skull and, lung and diaphragm hypoplasia. Variable components of SR include scoliosis, cleft sternum, exposure of thoracic viscera, and abnormalities of the digestive and urogenital systems. This report presents the findings from an anatomical analysis of a female Holstein SR calf with thoracoschisis, scoliosis and anomalies of the appendicular skeleton, cardiovascular, respiratory, digestive and urogenital systems. Many of these malformations have not been previously reported. The reproductive tract of this case is particularly unique, displaying Muellerian duct abnormalities. These abnormalities suggest SR occurs as early as the post-gastrulation embryo and involves the intermediate mesoderm. Preliminary analysis of associated cases suggests that SR has a genetic aetiology.

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.

Loss of AP-2alpha impacts multiple aspects of ventral body wall development and closure

Human birth defects involving the ventral body wall are common, yet little is known about the mechanism of body wall closure in mammals. The AP-2alpha transcription factor knock-out mouse provides an exceptional tool to understand this particular pathology, since it has one of the most severe ventral body wall closure defects, thoracoabdominoschisis. To gain insight into the complex morphological events responsible for body wall closure, we have studied this developmental process in AP-2alpha knock-out mice. Several tissues involved in normal ventral body wall closure are defective in the absence of AP-2alpha, including those associated with the primary body wall, the umbilical ring, and the mesoderm of the secondary body wall. These defects, coupled with the expression pattern of AP-2alpha, suggest that AP-2alpha is involved in multiple developmental mechanisms directing the morphogenesis of the ventral body wall, including cell migration, differentiation, and death. There is a failure of migration and fusion of the body folds at the umbilical ring, as well as in the formation and migration of the abdominal bands and ventral musculature. Furthermore, the mechanism of cell deposition at the umbilical ring is disturbed. Consequently, the mesodermal compartment of the body wall is underdeveloped. We also suggest that AP-2alpha is required for signaling from the surface ectoderm to the underlying mesoderm for proper development and closure of the ventral body wall. These findings provide a fundamental understanding of how AP-2alpha functions in the closure of the ventral body wall, as well as offer insight into related human birth defects.

Combined pentalogy of Cantrell with tetralogy of Fallot, gallbladder agenesis, and polysplenia: a case report

A male newborn with pentalogy of Cantrell, tetralogy of Fallot, agenesis of the gallbladder, and polysplenia died at 3 days of age. Polysplenia was not previously reported in this association.

Infant with midline thoracoabdominal schisis and limb defects

An infant presented with multiple congenital anomalies including a midline thoracoabdominal defect, absence of the sternum, ectopia cordis, right diaphragmatic hernia, right anophthalmia, left microphthalmia, incomplete bilateral cleft lip, and various limb defects including ectrodactyly of the right hand and left foot, and phocomelia of the right lower extremity. The infant expired soon after birth. The radiological findings included absence of the sternum, 11 right-sided ribs, absence of the middle third of the right clavicle, opaque right hemithorax, hypoplastic right tibia, absent right fibula and foot, and ectrodactyly of the right hand and left foot. In addition, the autopsy revealed two distinct diaphragmatic defects, an anterior midline defect of the diaphragm beneath the ectopic heart, and a large Bochdalek hernia, with abdominal contents in the chest. Our case has overlapping features with conditions such as thoracoabdominal syndrome, pentalogy of Cantrell, and limb-body wall complex, but the concurrence of midline body wall defect and ectrodactyly has not been described previously.

GPC4, the gene for human K-glypican, flanks GPC3 on xq26: deletion of the GPC3-GPC4 gene cluster in one family with Simpson-Golabi-Behmel syndrome

The glypicans constitute a growing family of cell surface heparan sulfate proteoglycans that may play a role in the control of cell division and growth regulation. Recently, deletions and translocations involving GPC3 (the gene for glypican-3, localized on Xq26) have been identified in patients with Simpson-Golabi-Behmel syndrome (SGBS). This X-linked syndrome is characterized by pre- and postnatal overgrowth, visceral and skeletal abnormalities, and a high risk for the development of embryonal tumors, mostly Wilms tumor and neuroblastoma. In the present report we show that the gene for human K-glypican/glypican-4 (GPC4) also maps to Xq26, centromeric to GPC3. The glypican-4 protein is encoded by nine exons. Establishment of a BAC/PAC contig physically linking GPC4 and GPC3 indicates that these two genes are arranged in a tandem array, the 5' end of GPC4 flanking the 3' end of GPC3. Unlike the glypican-3 message, the glypican-4 message is nearly ubiquitous. Analysis of DNA samples from eight patients with diagnosis of SGBS identified one individual with a deletion that involves the entire GPC4 gene and the last two exons of GPC3. The tight clustering of GPC3 and GPC4, with deletions that occasionally affect both genes, may be relevant for explaining the variability of the SGBS phenotype.