Overview of epidemiology, genetics, birth defects, and chromosome abnormalities associated with CDH

The role of FREM2 and FRAS1 in the development of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) has been reported twice in individuals with a clinical diagnosis of Fraser syndrome, a genetic disorder that can be caused by recessive mutations affecting FREM2 and FRAS1. In the extracellular matrix, FREM2 and FRAS1 form a self-stabilizing complex with FREM1, a protein whose deficiency causes sac CDH in humans and mice. By sequencing FREM2 and FRAS1 in a CDH cohort, and searching online databases, we identified five individuals who carried recessive or double heterozygous, putatively deleterious variants in these genes which may represent susceptibility alleles. Three of these alleles were significantly enriched in our CDH cohort compared with ethnically matched controls. We subsequently demonstrated that 8% of Frem2ne/ne and 1% of Fras1Q1263*/Q1263* mice develop the same type of anterior sac CDH seen in FREM1-deficient mice. We went on to show that development of sac hernias in FREM1-deficient mice is preceded by failure of anterior mesothelial fold progression resulting in the persistence of an amuscular, poorly vascularized anterior diaphragm that is abnormally adherent to the underlying liver. Herniation occurs in the perinatal period when the expanding liver protrudes through this amuscular region of the anterior diaphragm that is juxtaposed to areas of muscular diaphragm. Based on these data, we conclude that deficiency of FREM2, and possibly FRAS1, are associated with an increased risk of developing CDH and that loss of the FREM1/FREM2/FRAS1 complex, or its function, leads to anterior sac CDH development through its effects on mesothelial fold progression.

Intra-amniotic Sildenafil Treatment Modulates Vascular Smooth Muscle Cell Phenotype in the Nitrofen Model of Congenital Diaphragmatic Hernia

The etiology of pulmonary vascular abnormalities in CDH is incompletely understood. Studies have demonstrated improvement in pulmonary vasculature with prenatal therapy in animal models. We hypothesize that prenatal sildenafil may attenuate defective pulmonary vascular development via modulation of vSMC phenotype from undifferentiated, proliferative phenotype to differentiated, contractile phenotype. We utilized the nitrofen model of CDH to examine the effect of IA sildenafil on pulmonary vSMC phenotype during lung development. Timed-pregnant CD-1 mice were gavage fed 25 mg nitrofen or olive oil (control) at E8.5 of gestation. Single IA injections of Sildenafil (Revatio; 10 µL of 4 mg/4 ml solution) or dextrose control were performed at E12.5. Mice were sacrificed on various gestational days for embryonic lung harvest. Markers of vSMC development of undifferentiated and differentiated phenotypes were analyzed by immunostaining and western blot. Across all time points in gestation, nitrofen-treated embryonic lungs demonstrated increased vSMC expression of NOTCH3, Hes-5, PDGFR-β, desmin and α-SMA and decreased expression of calponin and SMMHC, compared to oil controls. IA dextrose treatment had no effect on expression levels. However, IA Sildenafil treatment resulted in down-regulation of NOTCH3, Hes-5, PDGFR-β, desmin and α-SMA and upregulation of calponin and SMMHC, comparable to oil controls. In the nitrofen model, vSMC express markers consistent with more undifferentiated proliferative phenotype, resulting in hypermuscularization of intrapulmonary arterioles in CDH. A single dose of IA Sildenafil treatment early in gestation, results in sustained normalization of vSMC phenotype. Pharmacologic modulation of the vSMC phenotype at key gestational points may have therapeutic potential.

Pulmonary Hypertension in Patients with Congenital Diaphragmatic Hernia: Does Lung Size Matter?

PURPOSE

 The relationship between pulmonary hypoplasia and pulmonary arterial hypertension (PHTN) in patients with congenital diaphragmatic hernia (CDH) remains ill-defined. We hypothesized that prenatal estimates of lung size would directly correlate with PHTN severity.

METHODS

 Infants with isolated CDH (born 2004-2015) at a single institution were included. Estimates of lung size included observed-to-expected LHR (o:eLHR) and %-predicted lung volumes (PPLV = observed/predicted volumes). The primary outcome was severity of PHTN (grade 0-3) on echocardiography performed between day of life 3 and 30.

RESULTS

 Among 62 patients included, there was 32% mortality and 65% ECMO utilization. PPLV (odds ratio [OR] = 0.94 per 1 grade in PHTN severity, 95% confidence interval [CI] = 0.89-0.98, p < 0.01) and o:eLHR (OR = 0.97, 95% CI = 0.94-0.99, p < 0.01) were significantly associated with PHTN grade. Among patients on ECMO, PPLV (OR = 0.92, 95% CI = 0.84-0.99, p = 0.03) and o:eLHR (OR = 0.95, 95% CI = 0.92-0.99, p = 0.01) were more strongly associated with PHTN grade. PPLV and o:eLHR were significantly associated with the use of inhaled nitric oxide (iNO) (OR = 0.90, 95% CI = 0.83-0.98, p = 0.01 and OR = 0.94, 95% CI = 0.91-0.98, p < 0.01, respectively) and epoprostenol (OR = 0.91, 95% CI = 0.84-0.99, p = 0.02 and OR = 0.93, 95% CI = 0.89-0.98, p < 0.01, respectively).

CONCLUSION

 Among infants with isolated CDH, PPLV, and o:eLHR were significantly associated with PHTN severity, especially among patients requiring ECMO. Prenatal lung size may help predict postnatal PHTN and associated therapies.

De novo variants in congenital diaphragmatic hernia identify MYRF as a new syndrome and reveal genetic overlaps with other developmental disorders

Congenital diaphragmatic hernia (CDH) is a severe birth defect that is often accompanied by other congenital anomalies. Previous exome sequencing studies for CDH have supported a role of de novo damaging variants but did not identify any recurrently mutated genes. To investigate further the genetics of CDH, we analyzed de novo coding variants in 362 proband-parent trios including 271 new trios reported in this study. We identified four unrelated individuals with damaging de novo variants in MYRF (P = 5.3x10(-8)), including one likely gene-disrupting (LGD) and three deleterious missense (D-mis) variants. Eight additional individuals with de novo LGD or missense variants were identified from our other genetic studies or from the literature. Common phenotypes of MYRF de novo variant carriers include CDH, congenital heart disease and genitourinary abnormalities, suggesting that it represents a novel syndrome. MYRF is a membrane associated transcriptional factor highly expressed in developing diaphragm and is depleted of LGD variants in the general population. All de novo missense variants aggregated in two functional protein domains. Analyzing the transcriptome of patient-derived diaphragm fibroblast cells suggest that disease associated variants abolish the transcription factor activity. Furthermore, we showed that the remaining genes with damaging variants in CDH significantly overlap with genes implicated in other developmental disorders. Gene expression patterns and patient phenotypes support pleiotropic effects of damaging variants in these genes on CDH and other developmental disorders. Finally, functional enrichment analysis implicates the disruption of regulation of gene expression, kinase activities, intra-cellular signaling, and cytoskeleton organization as pathogenic mechanisms in CDH.

Upregulated EFNB2 and EPHB4 promotes lung development in a nitrofen-induced congenital diaphragmatic hernia rat model

Congenital diaphragmatic hernia (CDH) is a common congenital malformation associated with high mortality rates, mainly due to pulmonary hypoplasia and persistent pulmonary hypertension following birth. The present study aimed to investigate abnormal lung development in a rat CDH model, and examine temporal and spatial changes in the expression of ephrin type‑B receptor 4 (EPHB4) and ephrin‑B2 (EFNB2) during fetal lung development, to elucidate the role of these factors during lung morphogenesis. Pregnant rats received nitrofen on embryonic day (E) 8.5 to induce CDH, and fetal lungs were collected on E13.5, E15.5, E17.5, E19.5, and E21.5. The mean linear intercept (MLI) and mean alveolar number (MAN) were observed in fetal lung tissue at E21.5 following hematoxylin and eosin staining. E13.5 fetal lungs were cultured for 96 h in serum‑free medium and branch development was observed under a microscope. The gene and protein expression levels of EPHB4 and EFNB2 were assessed by reverse transcription‑quantitative polymerase chain reaction analysis, and immunoblotting and immunohistochemistry, respectively. The fetal rat lungs were treated with EFNB2 and the activity of key signaling pathways was assessed. The lung index (lung weight/body weight) at E21.5 was significantly lower in the CDH rats, compared with that in the control fetal rats. The MLI and MAN were also lower in the CDH group. The number of lung terminal buds at E13.5 (embryonic stage), and the lung‑explant perimeter and surface were all smaller in the CDH group rats than in the control group at the same age. Pulmonary hypoplasia was observed following 96 h of in vitro culture. No significant differences were found in the expression levels of EFNB2 and EPHB4 between the CDH and control groups at E13.5 (embryonic stage) or E15.5 (pseudoglandular stage), however, EFNB2 and EPHB4 were significantly upregulated at E17.5 (canalicular stage), and at E19.5 and E21.5 (saccular/alveolar stages). EFNB2 stimulated pulmonary branching and EFNB2 supplementation decreased the activity of p38, c‑Jun NH2‑terminal kinase, extracellular signal‑regulated kinase, and signal transducer and activator of transcription. The CDH fetal rats developed pulmonary dysplasia at an early stage of fetal pulmonary development. Upregulated expression of EFNB2 and EPHB4 was observed in the rat lung of nitrofen‑induced CDH, and the increased expression of EFNB2 promoted rat lung development in the nitrofen‑induced CDH model.

The impact of fetal endoscopic tracheal occlusion in isolated left-sided congenital diaphragmatic hernia on left-sided cardiac dimensions

OBJECTIVES

Fetal endoscopic tracheal occlusion (FETO) is offered to fetuses with congenital diaphragmatic hernia (CDH) and severe lung hypoplasia to promote lung growth and may secondarily affect left heart growth. The effects of FETO on left heart hypoplasia (LHH) are not described post-CDH repair.

METHODS

A retrospective analysis was performed for fetuses with left-sided CDH who underwent FETO and severity-matched controls from 2007 to 2016 at our institution. Echocardiographic, ultrasound, and MRI data were reviewed. Left heart dimensions were assessed prenatally and postnatally. Primary clinical outcome evaluated was death.

RESULTS

Twelve FETO patients and 18 controls were identified. Fetal LHH was noted in both groups and worsened after FETO. Postnatal mitral valve dimensions were larger in the FETO group pre-CDH repair (P = .03). Post-CDH repair, mitral valve and left ventricular dimensions were not significantly different between groups (P = .79 and P = .63 respectively) while FETO aortic valve dimensions were smaller (P = .04). Extracorporeal membrane oxygenation use was lower in the FETO group. No associations were found between left heart dimensions and outcomes.

CONCLUSION

Although increased lung growth was seen after FETO, fetal LHH persisted with relative normalization seen post-repair. Persistent LHH post-FETO could be secondary to a small contribution of pulmonary venous return to the fetal left heart and increased intrathoracic pressures post-FETO.

Trends, correlates, and survival of infants with congenital diaphragmatic hernia and its subtypes

OBJECTIVE

To identify the live-birth prevalence, trends, correlates, and neonatal and 1-year survival rates of congenital diaphragmatic hernia.

METHODS

Using a population-based, retrospective cohort study design, we examined 1,025 cases of congenital diaphragmatic hernia from the 1998-2012 Florida Birth Defects Registry. We used Poisson and joinpoint regression models to compute prevalence ratios and temporal trends, respectively. Kaplan-Meier survival curves and Cox proportional hazards regression were used to describe neonatal and 1-year survival and estimate hazard ratios representing the predictors of infant survival.

RESULTS

The birth prevalence of congenital diaphragmatic hernia was 3.19 per 10,000 live births (95% confidence interval [CI]: 3.00-3.39); there was a 4.2% yearly increase among multiple cases only. Among all cases, maternal education less than high school (prevalence ratio: 1.25, 95% CI: 1.02-1.53), high school/associate degree/GED (prevalence ratio: 1.15, 95% CI: 1.01-1.32), multiple birth (prevalence ratio: 1.38, 95% CI: 1.05-1.81), and male sex (prevalence ratio: 1.18, 95% CI: 1.05-1.32) were associated with increased risk for congenital diaphragmatic hernia. The 24-hr, neonatal, and 1-year survival rates were 93.6%, 79.8%, and 71.2%, respectively. The highest hazard ratio of 17.87 (95% CI: 1.49-213.82) was observed for neonatal mortality among cases associated with chromosomal anomalies and born <37 weeks at < 1,500 g. Among isolated cases, multiple birth (hazard ratio: 0.41, 95% CI: 0.20-0.86) was associated with decreased 1-year mortality.

CONCLUSION

Low maternal education and multiple birth may be linked to congenital diaphragmatic hernia. The trends in prevalence, epidemiologic correlates, and predictors of early survival can differ between congenital diaphragmatic hernia subtypes-isolated, multiple, and chromosomal.© 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Systematic analysis of copy number variation associated with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH), characterized by malformation of the diaphragm and hypoplasia of the lungs, is one of the most common and severe birth defects, and is associated with high morbidity and mortality rates. There is growing evidence demonstrating that genetic factors contribute to CDH, although the pathogenesis remains largely elusive. Single-nucleotide polymorphisms have been studied in recent whole-exome sequencing efforts, but larger copy number variants (CNVs) have not yet been studied on a large scale in a case control study. To capture CNVs within CDH candidate regions, we developed and tested a targeted array comparative genomic hybridization platform to identify CNVs within 140 regions in 196 patients and 987 healthy controls, and identified six significant CNVs that were either unique to patients or enriched in patients compared with controls. These CDH-associated CNVs reveal high-priority candidate genes including HLX, LHX1, and HNF1B We also discuss CNVs that are present in only one patient in the cohort but have additional evidence of pathogenicity, including extremely rare large and/or de novo CNVs. The candidate genes within these predicted disease-causing CNVs form functional networks with other known CDH genes and play putative roles in DNA binding/transcription regulation and embryonic development. These data substantiate the importance of CNVs in the etiology of CDH, identify CDH candidate genes and pathways, and highlight the importance of ongoing analysis of CNVs in the study of CDH and other structural birth defects.

Developmental origin and morphogenesis of the diaphragm, an essential mammalian muscle

The diaphragm is a mammalian skeletal muscle essential for respiration and for separating the thoracic and abdominal cavities. Development of the diaphragm requires the coordinated development of muscle, muscle connective tissue, tendon, nerves, and vasculature that derive from different embryonic sources. However, defects in diaphragm development are common and the cause of an often deadly birth defect, Congenital Diaphragmatic Hernia (CDH). Here we comprehensively describe the normal developmental origin and complex spatial-temporal relationship between the different developing tissues to form a functional diaphragm using a developmental series of mouse embryos genetically and immunofluorescently labeled and analyzed in whole mount. We find that the earliest developmental events are the emigration of muscle progenitors from cervical somites followed by the projection of phrenic nerve axons from the cervical neural tube. Muscle progenitors and phrenic nerve target the pleuroperitoneal folds (PPFs), transient pyramidal-shaped structures that form between the thoracic and abdominal cavities. Subsequently, the PPFs expand across the surface of the liver to give rise to the muscle connective tissue and central tendon, and the leading edge of their expansion precedes muscle morphogenesis, formation of the vascular network, and outgrowth and branching of the phrenic nerve. Thus development and morphogenesis of the PPFs is critical for diaphragm formation. In addition, our data indicate that the earliest events in diaphragm development are critical for the etiology of CDH and instrumental to the evolution of the diaphragm. CDH initiates prior to E12.5 in mouse and suggests that defects in the early PPF formation or their ability to recruit muscle are an important source of CDH. Also, the recruitment of muscle progenitors from cervical somites to the nascent PPFs is uniquely mammalian and a key developmental innovation essential for the evolution of the muscularized diaphragm.

Congenital diaphragmatic hernia and double-outlet right ventricle: elements of trisomy 18?

We present a case of a term male neonate born with congenital diaphragmatic hernia (CDH), double-outlet right ventricle (DORV) and a “picture of genetic syndrome”, antenatally diagnosed, without any confirmation of a particular syndrome as no amnioparacentesis was performed. The postnatal chromosomal analysis revealed trisomy 18.

Morphological Characterization of Diaphragm in Common Squirrel Monkey (Saimiri sciureus)

The wall of the diaphragm can be affected by congenital or acquired alterations which allow the passage of viscera between the abdominal and chest cavities, allowing the formation of a diaphragmatic hernia. We characterized morphology and performed biometrics of the diaphragm in the common squirrel monkey Saimiri sciureus. After fixation, muscle fragments were collected and processed for optical microscopy. In this species the diaphragm muscle is attached to the lung by phrenopericardial ligament. It is also connected to the liver via the coronary and falciform ligaments. The muscle is composed of three segments in total: 1) sternal; 2) costal, and 3) a segment consisting of right and left diaphragmatic pillars. The anatomical structures analyzed were similar to those reported for other mammals. Histological analysis revealed stable, organized muscle fibers with alternation of light and dark streaks, indicating transverse striation.

Congenital diaphragmatic hernia as a part of Nance-Horan syndrome?

Nance-Horan syndrome is a rare X-linked developmental disorder characterized by bilateral congenital cataract, dental anomalies, facial dysmorphism, and intellectual disability. Here, we identify a patient with Nance-Horan syndrome caused by a new nonsense NHS variant. In addition, the patient presented congenital diaphragmatic hernia. NHS gene expression in murine fetal diaphragm was demonstrated, suggesting a possible involvement of NHS in diaphragm development. Congenital diaphragmatic hernia could result from NHS loss of function in pleuroperitoneal fold or in somites-derived muscle progenitor cells leading to an impairment of their cells migration.

Right versus left congenital diaphragmatic hernia - What's the difference?

BACKGROUND

Right-sided congenital diaphragmatic hernias (CDH) and bigger defect sizes have been associated with poorer outcomes.

AIM

The aim of this study was to evaluate right- and left-sided CDH in terms of size, survival, associated anomalies, and morbidity.

MATERIAL AND METHODS

We used information from a multicenter, multinational database including patients with CDH born between 2007 and 2015. All infants with data on defect side were included for this analysis. We compared differences in outcomes between right- and left-sided CDH. Further analysis on the association between side, size of the defect, and outcome was performed.

RESULTS

A total of 3754 cases of CDH were entered in the registry between January 2007 and September 2015, with an overall survival of 71%. Of those, 598 (16%) were right-sided and 3156 left-sided, with a survival rate of 67% and 72%, respectively. Right-sided CDH had a larger proportion of C and D defects (p<0.001 and 0.04, respectively). Survival rates for the same size defect were similar, independent of the side of the defect. Multivariable logistic regression analysis with survival as dependent variable identified a significant correlation with defect size, but not side.

CONCLUSIONS

The higher proportion of large defects (C & D) in right-sided CDH, not the side itself, accounts for the reported poorer survival in right-sided CDH.

LEVEL OF EVIDENCE

Level I for a prognosis study - This is a high-quality, prospective cohort study with 99% of patients followed to the study end point (death or discharge).

Congenital diaphragmatic hernias: from genes to mechanisms to therapies

Congenital diaphragmatic hernias (CDHs) and structural anomalies of the diaphragm are a common class of congenital birth defects that are associated with significant morbidity and mortality due to associated pulmonary hypoplasia, pulmonary hypertension and heart failure. In ∼30% of CDH patients, genomic analyses have identified a range of genetic defects, including chromosomal anomalies, copy number variants and sequence variants. The affected genes identified in CDH patients include transcription factors, such as GATA4, ZFPM2, NR2F2 and WT1, and signaling pathway components, including members of the retinoic acid pathway. Mutations in these genes affect diaphragm development and can have pleiotropic effects on pulmonary and cardiac development. New therapies, including fetal endoscopic tracheal occlusion and prenatal transplacental fetal treatments, aim to normalize lung development and pulmonary vascular tone to prevent and treat lung hypoplasia and pulmonary hypertension, respectively. Studies of the association between particular genetic mutations and clinical outcomes should allow us to better understand the origin of this birth defect and to improve our ability to predict and identify patients most likely to benefit from specialized treatment strategies.

Addressing the hidden mortality in CDH: A population-based study

BACKGROUND

Improvements in the clinical management of CDH have led to overall improved reported result from single institutions. However, population-based studies have highlighted a hidden mortality.

AIM

To explore the incidence in Sweden and to address the hidden mortality for CDH during a 27-year period in a population-based setting.

MATERIALS AND METHODS

This is a population based cohort study that includes all patients diagnosed with CDH that were registered in the National Patient Register, the Medical Birth Register, the Register of Congenital Malformations and the Register for Causes of Death between 1987 and 2013. The mortality rates were calculated based on the number deaths divided by the number of live born cases. The hidden mortality was defined as the number of CDH cases that were not born (because of TOP or IUFD), cases of neonatal demise during birth or demise the same day of birth in patients who were in peripheral institutions and who never reached tertiary centers.

RESULTS

In total, 861 CDH patients were born in Sweden between 1987 and 2013, which corresponds to an incidence of 3.0 born CDH per 10,000 live births. When adding the cases of TOP and IUFD, the total incidence of CDH in Sweden was 3.5/10,000 live born. The mortality rate between 1987 and 2013 was 36%: 44% during the first time period 1987-1999 and 27% in the later period 2000-2013. The hidden mortality in the second period was 30%, resulting in a total mortality rate of 45%.

CONCLUSION

The incidence of CDH during a 27-year period remained unchanged in the population. However, we observed a decrease in the prevalence because of the increasing numbers of TOP. A significant hidden mortality exists, with overall mortality rate of 45% for CDH in this population.

LEVEL OF EVIDENCE

II (cohort).

Genome-wide enrichment of damaging de novo variants in patients with isolated and complex congenital diaphragmatic hernia

Congenital Diaphragmatic Hernia (CDH) is a common and often lethal birth defect characterized by diaphragmatic structural defects and pulmonary hypoplasia. CDH is isolated in 60% of newborns, but may also be part of a complex phenotype with additional anomalies. We performed whole exome sequencing (WES) on 87 individuals with isolated or complex CDH and on their unaffected parents, to assess the contribution of de novo mutations in the etiology of diaphragmatic and pulmonary defects and to identify new candidate genes. A combined analysis with 39 additional trios with complex CDH, previously published, revealed a significant genome-wide burden of de novo variants compared to background mutation rate and 900 control trios. We identified an increased burden of likely gene-disrupting (LGD, i.e. nonsense, frameshift, and canonical splice site) and predicted deleterious missense (D-mis) variants in complex and isolated CDH patients. Overall, an excess of predicted damaging de novo LGD and D-mis variants relative to the expected frequency contributed to 21% of complex cases and 12% of isolated CDH cases. The burden of de novo variants was higher in genes expressed in the developing mouse diaphragm and heart. Some overlap with genes responsible for congenital heart defects and neurodevelopmental disorders was observed in CDH patients within our cohorts. We propose that de novo variants contribute significantly to the development of CDH.

Congenital malformations according to etiology in newborns from the floricultural zone of Mexico state

Birth defects are the number one cause of child mortality worldwide and in 2010 it was the second cause in Mexico. Congenital malformations are a public health issue, because they cause infant mortality, chronic disease and disability. The origin can be genetic, environmental or unknown causes. Among environmental contaminants, pesticides stand out. In this study, we determine the frequency and etiology of congenital malformations in newborns (NBs) of a floricultural community and we compare it with that in the urban community. For 18 months, the NBs were monitored at the Tenancingo General Hospital and the Mother and Child Gynecology and Obstetrics Hospital (IMIEM) in Toluca. The identification of these malformations was carried out in accordance with the WHO. In Tenancingo, 1149 NBs were viewed, where 20% had some kind of congenital malformations. While in the IMIEM, 5069 were reviewed and 6% had some malformation. According to the etiology, in Tenancingo, 69% were multifactorial, 28% were monogenetic and 2% were chromosomal. In the IMIEM, 47% were multifactorial, then 18.3% were monogenetic and 2.8% were chromosomal. There was a significant difference between the global frequency of malformations and the multifactorial etiology of both institutions. Our results show that congenital malformations in the NBs occurred more frequently in the floricultural zone and that because the percentage of multifactorial etiology is higher, it is likely there is an association with exposure to pesticides.

Hybrid Stage I Procedure as Initial Palliation for Neonate With Hypoplastic Left Heart Syndrome and Right Congenital Diaphragmatic Hernia

During the past decade, a hybrid procedure has emerged and dramatically evolved as an alternative stage I palliation to the conventional Norwood procedure in neonates with hypoplastic left heart syndrome (HLHS). The hybrid approach avoids the need for cardiopulmonary bypass (CPB) utilizing stenting of the arterial duct and bilateral pulmonary artery banding. Cerebral and coronary perfusion pressure is maintained, and the pulmonary vasculature is protected from higher systemic pressure. Elimination of risks associated with CPB gains vital time to stabilize the patient and correct coexisting noncardiac anomalies and allows growth in preparation for the later stages of the Fontan pathway. The association of HLHS with right congenital diaphragmatic hernia (CDH) is rare. We report performing a successful hybrid stage I palliation on a neonate with HLHS and severe right CDH.

Morgagni's Hernia: Analysis of 21 Patients with Our Clinical Experience in Diagnosis and Treatment

A Morgagni's hernia is a congenital defect found in the anterior aspect of the diaphragm between the costal and the sternal portions of this muscle. This defect is also referred to as the space of Larrey. It has been reported that 70% of patients with Morgagni's hernia are female, 90% of the hernias are right-sided, and 92% of the hernias have hernia sacs. This type of hernia is a rare clinical entity and accounts for 3% of all surgically treated diaphragmatic hernias. There are no large retrospective or prospective studies on this topic. This type of hernia is a rare type among adults without a well-described prevalence and without well-established definitive management strategies. There are also few clinical reports about this clinical entity and its surgical treatment. We treated 21 patients with Morgagni's hernia in a 12-year period, and we report our experience while discussing the surgical treatment of this disease. We performed a retrospective review of the 21 patients who were operated between 2003 and 2015. These patients had undergone surgical repair of Morgagni's hernia. For each subject, demographic data, symptoms of presentation, physical examination findings, preoperative imaging studies and diagnosis, and surgical procedures were documented. Location of the hernia sac and its contents, postoperative complications, and duration of hospital stay were recorded and evaluated. Twelve patients were females and nine were males. The mean age of patients was 63.85 years. Dyspnea was the most prominent symptom in our patients. Morgagni's hernias were located on the right side in 19 patients and on the left side in 2 patients. Chest X-ray in 10 patients and abdominal computerized tomography in 17 patients were the major diagnostic tools. Four patients were operated as emergency while others underwent elective surgery (17 patients). Twelve patients were operated with laparoscopy and the remaining nine were operated with the conventional open abdominal technique. Hernia sacs were observed in all of the patients and removed except in four of them. The omentum and the transverse colon were the most commonly seen organs in hernia sacs. Hernia defects were repaired with primary sutures in four patients (all open cases) and primary closure supported with mesh in six patients (four laparoscopic, two open cases). In the remaining 11 patients, hernia defects were closed with synthetic meshes (eight laparoscopic, three open cases). Mean postoperative hospital stay was 9.8 days. No recurrence was observed in any patients. Only one of our patients died during follow-up. In Morgagni's hernias, surgical intervention is necessary as the hernia may cause complications such as strangulation of the colon or intestines. A laparoscopic approach has increased its popularity in recent years because of the well-known advantages of laparoscopy.

Fetal stomach and gallbladder in contact with the bladder wall is a common ultrasound sign of stomach-down left congenital diaphragmatic hernia

PURPOSE

The aim of this study was to identify sonographic (US) findings that can assist in prenatal diagnosis of stomach-down left congenital diaphragmatic hernia (CDH), specifically related to positioning of the abdominal contents including the stomach, bladder, and gallbladder.

METHODS

All US examinations with a postnatally confirmed diagnosis of stomach-down left CDH over a 13-year period were retrospectively reviewed for abnormal position of the abdominal contents, including whether the fetal stomach was in contact with the urinary bladder. Normal fetuses that underwent comprehensive US surveys were similarly evaluated for comparison in a 2:1 ratio.

RESULTS

Twenty-two fetuses with stomach-down left CDH were identified in a cohort of 278 fetuses with left CDH. In 15/22 (68.2%) cases of stomach-down left CDH, the bladder and stomach walls were in contact. Contact of the fetal gallbladder with the fetal bladder wall was also observed and was present even more commonly (17/22 cases [77.3%]). There was no case of either the stomach or gallbladder in contact with the bladder wall in the normal fetal cohort (n = 44).

CONCLUSIONS

Recognition of the fetal stomach and/or gallbladder in contact with the bladder wall can help in the detection of stomach-down left CDH. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:8-13, 2017.

Complete Bilateral Agenesis of the Diaphragm

Bilateral agenesis of the diaphragm is a very rare congenital diaphragmatic defect. Bilateral congenital diaphragmatic hernia (CDH) is much more frequently associated with other anomalies compared with unilateral CDH (70% vs 30%-40%). These include cardiovascular, respiratory (other than lung hypoplasia), gastrointestinal, renal, and genital malformations. We report a case of complete bilateral agenesis of the diaphragm associated with a horseshoe kidney and an imperforate anus. These additional malformations have not previously been reported in association with complete bilateral agenesis of the diaphragm. We also present a review of previous cases of total diaphragm agenesis published in the English language and provide some insights about pathogenesis.

Congenital diaphragmatic hernia causing cardiac arrest in a 30-year-old woman

Congenital diaphragmatic hernia (CDH) usually presents in infancy with respiratory failure requiring urgent surgical correction. Mortality in this group of patients remains poor and persistent pulmonary hypertension is a significant contributor. It is therefore rare for patients to reach adulthood undiagnosed. CDH is often identified incidentally in adults but when symptoms arise, they relate to the organ involved, and include gastrointestinal symptoms of dyspepsia and obstruction, as well as respiratory complaints such as dyspnoea. We present the case of a 30-year-old woman who was admitted with non-specific symptoms of upper abdominal discomfort but whose deteriorating condition culminated in a cardiac arrest, as an unreported presentation of CDH. The patient presented initially with severe left upper quadrant pain. Her chest x-ray on admission suggested a raised left hemidiaphragm. She went on to have computed tomography (CT) of the thorax and abdomen as well as oesophagogastroduodenoscopy, which raised the suspicion of diaphragmatic eventration. Repeat CT was performed after the patient collapsed on the ward five days following admission, revealing tracheal deviation, and a strangulated Bochdalek hernia containing stomach and spleen. After transfer to the anaesthetic room, she suffered a cardiac arrest. Advanced life support was required to return spontaneous cardiac function. She was intubated and ventilated, and a needle thoracostomy was performed to decompress the tension gastrothorax. Emergency laparotomy revealed a gangrenous stomach and spleen. Total gastrectomy with primary Roux-en-Y reconstruction, splenectomy and insertion of a feeding jejunostomy were performed. The patient recovered well postoperatively and was discharged two weeks following surgery.

Whole exome sequencing and array-based molecular karyotyping as aids to prenatal diagnosis in fetuses with suspected Simpson-Golabi-Behmel syndrome

OBJECTIVE

Simpson-Golabi-Behmel (SGBS) syndrome type 1 and type 2 represent rare X-linked prenatal overgrowth disorders. The aim of our study is to describe the prenatal sonographic features as well as the genetic work-up.

METHOD

Retrospective analysis of four cases with a pre- or postnatal diagnosis of SGBS in a single tertiary referral center within a period of 4 years.

RESULTS

In the study period, four male fetuses with SGBS were detected. The final diagnosis was made prenatally in three cases. In all cases the second trimester anomaly scan revealed left sided congenital diaphragmatic hernia (CDH) with additional anomalies; three fetuses with SGBS type 1 showed fetal overgrowth. In two of these, whole exome sequencing showed a possible frameshift mutation and a point mutation in the gene GPC3, respectively. In the third case, multiplex ligation-dependent probe amplification (MLPA) revealed a hemizygous duplication of exon 3-7 in the gene GPC3. In the fourth case, SGBS type 2 was confirmed by array comparative genomic hybridization (CGH) of amniotic fluid cells showing a deletion of the gene OFD1.

CONCLUSION

We could demonstrate, that in the presence of a CDH, syndromes of the fetus can be increasingly differentiated by detailed sonography followed by a selective and graded molecular diagnostic using microarray techniques and whole exome sequencing. © 2016 John Wiley & Sons, Ltd.

Follow-up of asymptomatic adult diaphragmatic hernia: should patients with this condition undergo immediate operation? A report of two cases

BACKGROUND

Asymptomatic diaphragmatic hernia is generally thought to be rare among adults. We present two different types of asymptomatic diaphragmatic hernia diagnosed with computed tomography (CT) and discuss treatment strategies.

CASE PRESENTATION

Case 1: A 37-year-old woman was diagnosed with catamenial pneumothorax in the right diaphragm. Partial resection of the diaphragm and lung was performed using a linear stapler. She was asymptomatic after the operation and gave birth 2 years later. After delivery, she experienced recurrent pneumothorax, and CT revealed a right diaphragmatic defect with herniation of a part of the liver into the thorax. An iatrogenic diaphragmatic hernia was diagnosed. There has been no change in the size of the hernia and no symptoms due to the diaphragmatic hernia for more than 3 years after it was diagnosed. Case 2: A 75-year-old woman was previously diagnosed with rectal cancer and had undergone surgery after chemoradiotherapy. One year after surgery, herniation of a 3 × 1.3-cm section of retroperitoneal fat tissue into the left thoracic cavity was observed incidentally at a follow-up CT and was diagnosed as an adult Bochdalek hernia (BH). We reviewed the patient's past CT findings and confirmed that the same finding had been present since the first scan. A wait-and-see approach was chosen because there had been no change in the size of hernia, there were no symptoms, the patient was elderly, and there was a high risk of recurrence of the rectal cancer. She has had no symptoms to date, and careful follow-up has been performed.

CONCLUSIONS

There are few reports of asymptomatic adult diaphragmatic hernia. Although symptomatic diaphragmatic hernia is generally treated surgically, there are cases in which a wait-and-see approach has been applied, such as our asymptomatic cases.

Polygenic Causes of Congenital Diaphragmatic Hernia Produce Common Lung Pathologies

Congenital diaphragmatic hernia (CDH) is one of the most common and lethal congenital anomalies, and significant evidence is available in support of a genetic contribution to its etiology, including single-gene knockout mice associated with diaphragmatic defects, rare monogenetic disorders in humans, familial aggregation, and association of CDH with chromosomal abnormalities. Structural lung defects in the form of lung hypoplasia are almost invariably seen in patients with CDH and frequently in animal models of this condition. Better understanding of the mechanisms of pulmonary defects in CDH has the potential for creating targeted therapies, particularly in postnatal stages, when therapeutics can have maximum clinical impact on the surviving cohorts. Successful treatment of CDH is dependent on the integration of human genomic and genetic data with developmental expression profiling, mouse knockouts, and gene network and pathway modeling, which have generated a large number of candidate genes and pathways for follow-up studies. In particular, defective alveolarization appears to be a common and potentially actionable phenotype in both patients and animal models.

Maternal and community predictors of gastroschisis and congenital diaphragmatic hernia in Canada

PURPOSE

The incidence of gastroschisis (GS) has increased globally. Maternal age and smoking are risk factors and aboriginal communities may be more commonly affected. Factors leading to this increased incidence are otherwise unclear. We investigate maternal sociodemography, air pollution and personal risk factors comparing mothers of infants with GS with a control group of infants with diaphragmatic hernia (CDH) in a large population-based analysis.

METHODS

Data were collected from a national, disease-specific pediatric surgical database (May 2006-June 2013). Maternal community sociodemographic information was derived from the Canadian 2006 Census. Univariate and multivariable analyses were performed examining maternal factors related to diagnosis of GS.

RESULTS

GS infants come from poorer, less educated communities with more unemployment, less pollution, fewer immigrants, and more aboriginal peoples than infants with CDH. Teen maternal age, smoking, and illicit drug use, are associated with GS.

CONCLUSION

Mothers of infants with GS are younger, more likely to smoke and come from socially disadvantaged communities with higher proportions of aboriginal peoples but lower levels of air pollution compared to mothers of CDH infants. Identification of maternal risks provides direction for prenatal screening and public health interventions.

Wt1 and β-catenin cooperatively regulate diaphragm development in the mouse

The developing diaphragm consists of various differentiating cell types, many of which are not well characterized during organogenesis. One important but incompletely understood tissue, the diaphragmatic mesothelium, is distinctively present from early stages of development. Congenital Diaphragmatic Hernia (CDH) occurs in humans when diaphragm tissue is lost during development, resulting in high morbidity and mortality postnatally. We utilized a Wilms Tumor 1 (Wt1) mutant mouse model to investigate the involvement of the mesothelium in normal diaphragm signaling and development. Additionally, we developed and characterized a Wt1(CreERT2)-driven β-catenin loss-of-function model of CDH after finding that canonical Wnt signaling and β-catenin are reduced in Wt1 mutant mesothelium. Mice with β-catenin loss or constitutive activation induced in the Wt1 lineage are only affected when tamoxifen injection occurs between E10.5 and E11.5, revealing a critical time-frame for Wt1/ β-catenin activity. Conditional β-catenin loss phenocopies the Wt1 mutant diaphragm defect, while constitutive activation of β-catenin on the Wt1 mutant background is sufficient to close the diaphragm defect. Proliferation and apoptosis are affected, but primarily these genetic manipulations appear to lead to a change in normal diaphragm differentiation. Our data suggest a fundamental role for mesothelial signaling in proper formation of the diaphragm.

Neuroendocrine factors regulate retinoic acid receptors in normal and hypoplastic lung development

KEY POINTS

Retinoic acid (RA) and ghrelin levels are altered in human hypoplastic lungs when compared to healthy lungs. Although considerable data have been obtained about RA, ghrelin and bombesin in the congenital diaphragmatic hernia (CDH) rat model, neuroendocrine factors have never been associated with the RA signalling pathway in this animal model. In this study, the interaction between neuroendocrine factors and RA was explored in the CDH rat model. The authors found that normal fetal lung explants treated with RA, bombesin and ghrelin showed an increase in lung growth. Hypoplastic lungs presented higher expression levels of the RA receptors α and γ. Moreover bombesin and ghrelin supplementation, in vitro, to normal lungs increased RA receptor α/γ expression whereas administration of bombesin and ghrelin antagonists to normal and hypoplastic lungs decreased it. These data reveal for the first time that there is a link between neuroendocrine factors and RA, and that neuroendocrine factors sensitise the lung to the RA action through RA receptor modulation.

ABSTRACT

Congenital diaphragmatic hernia (CDH) is characterised by a spectrum of lung hypoplasia and consequent pulmonary hypertension, leading to high morbidity and mortality rates. Moreover, CDH has been associated with an increase in the levels of pulmonary neuroendocrine factors, such as bombesin and ghrelin, and a decrease in the action of retinoic acid (RA). The present study aimed to elucidate the interaction between neuroendocrine factors and RA. In vitro analyses were performed on Sprague-Dawley rat embryos. Normal lung explants were treated with bombesin, ghrelin, a bombesin antagonist, a ghrelin antagonist, dimethylsulfoxide (DMSO), RA dissolved in DMSO, bombesin plus RA and ghrelin plus RA. Hypoplastic lung explants (nitrofen model) were cultured with bombesin, ghrelin, bombesin antagonist or ghrelin antagonist. The lung explants were analysed morphometrically, and retinoic acid receptor (RAR) α, β and γ expression levels were assessed via Western blotting. Immunohistochemistry analysis of RAR was performed in normal and hypoplastic lungs 17.5 days post-conception (dpc). Compared with the controls, hypoplastic lungs exhibited significantly higher RARα/γ expression levels. Furthermore considering hypoplastic lungs, bombesin and ghrelin antagonists decreased RARα/γ expression. Normal lung explants (13.5 dpc) treated with RA, bombesin plus RA, ghrelin plus RA, bombesin or ghrelin exhibited increased lung growth. Moreover, bombesin and ghrelin increased RARα/γ expression levels, whereas the bombesin and ghrelin antagonists decreased RARα/γ expression. This study demonstrates for the first time that neuroendocrine factors function as lung growth regulators, sensitising the lung to the action of RA through up-regulation of RARα and RARγ.

Increased burden of de novo predicted deleterious variants in complex congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a serious birth defect that accounts for 8% of all major birth anomalies. Approximately 40% of cases occur in association with other anomalies. As sporadic complex CDH likely has a significant impact on reproductive fitness, we hypothesized that de novo variants would account for the etiology in a significant fraction of cases. We performed exome sequencing in 39 CDH trios and compared the frequency of de novo variants with 787 unaffected controls from the Simons Simplex Collection. We found no significant difference in overall frequency of de novo variants between cases and controls. However, among genes that are highly expressed during diaphragm development, there was a significant burden of likely gene disrupting (LGD) and predicted deleterious missense variants in cases (fold enrichment = 3.2, P-value = 0.003), and these genes are more likely to be haploinsufficient (P-value = 0.01) than the ones with benign missense or synonymous de novo variants in cases. After accounting for the frequency of de novo variants in the control population, we estimate that 15% of sporadic complex CDH patients are attributable to de novo LGD or deleterious missense variants. We identified several genes with predicted deleterious de novo variants that fall into common categories of genes related to transcription factors and cell migration that we believe are related to the pathogenesis of CDH. These data provide supportive evidence for novel genes in the pathogenesis of CDH associated with other anomalies and suggest that de novo variants play a significant role in complex CDH cases.

Muscle connective tissue controls development of the diaphragm and is a source of congenital diaphragmatic hernias

The diaphragm is an essential mammalian skeletal muscle, and defects in diaphragm development are the cause of congenital diaphragmatic hernias (CDH), a common and often lethal birth defect. The diaphragm is derived from multiple embryonic sources, but how these give rise to the diaphragm is unknown and, despite the identification of many CDH-associated genes, the etiology of CDH is incompletely understood. Using mouse genetics, we show that the pleuroperitoneal folds (PPFs), transient embryonic structures, are the source of the diaphragm’s muscle connective tissue, regulate muscle development, and their striking migration controls diaphragm morphogenesis. Furthermore, Gata4 mosaic mutations in PPF-derived muscle connective tissue fibroblasts result in the development of localized amuscular regions that are biomechanically weaker and more compliant and lead to CDH. Thus the PPFs and muscle connective tissue are critical for diaphragm development and mutations in PPF-derived fibroblasts are a source of CDH.

FBN1 contributing to familial congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a relatively common, life--threatening birth defect. We present a family with recurrent CDH--paraesophageal and central--for whom exome sequencing (ES) revealed a frameshift mutation (c.4969_4970insA, p.Ile1657Asnfs*30) in the fibrillin 1 gene (FBN1) that causes Marfan syndrome. A diagnosis of Marfan syndrome had not been considered previously in this family. However, a review of the literature demonstrated that FBN1 mutations have an unusual pattern of CDH in which paraesophageal hernias are particularly common. Subsequent clinical evaluations revealed evidence for ectopia lentis in affected family members supporting a clinical diagnosis of Marfan syndrome. Since only two other cases of familial CDH have been described in association with FBN1 mutations, we investigated an oligogenic hypothesis by examining ES data for deleterious sequence changes in other CDH-related genes. This search revealed putatively deleterious sequence changes in four other genes that have been shown to cause diaphragm defects in humans and/or mice--FREM1, DES, PAX3 and MET. It is unclear whether these changes, alone or in aggregate, are contributing to the development of CDH in this family. However, their individual contribution is likely to be small compared to that of the frameshift mutation in FBN1. We conclude that ES can be used to identify both major and minor genetic factors that may contribute to CDH. These results also suggest that ES should be considered in the diagnostic evaluation of individuals and families with CDH, particularly when other diagnostic modalities have failed to reveal a molecular etiology.

Epidemiology of congenital diaphragmatic hernia in Europe: a register-based study

INTRODUCTION

Published prevalence rates of congenital diaphragmatic hernia (CDH) vary. This study aims to describe the epidemiology of CDH using data from high-quality, population-based registers belonging to the European Surveillance of Congenital Anomalies (EUROCAT).

METHODS

Cases of CDH delivered between 1980 and 2009 notified to 31 EUROCAT registers formed the population-based case series. Prevalence over time was estimated using multilevel Poisson regression, and heterogeneity between registers was evaluated from the random component of the intercept.

RESULTS

There were 3373 CDH cases reported among 12 155 491 registered births. Of 3131 singleton cases, 353 (10.4%) were associated with a chromosomal anomaly, genetic syndrome or microdeletion, 784 (28.2%) were associated with other major structural anomalies. The male to female ratio of CDH cases overall was 1:0.69. Total prevalence was 2.3 (95% CI 2.2 to 2.4) per 10 000 births and 1.6 (95% CI 1.6 to 1.7) for isolated CDH cases. There was a small but significant increase (relative risk (per year)=1.01, 95% credible interval 1.00-1.01; p=0.030) in the prevalence of total CDH over time but there was no significant increase for isolated cases (ie, CDH cases that did not occur with any other congenital anomaly). There was significant variation in total and isolated CDH prevalence between registers. The proportion of cases that survived to 1 week was 69.3% (1392 cases) for total CDH cases and 72.7% (1107) for isolated cases.

CONCLUSIONS

This large population-based study found an increase in total CDH prevalence over time. CDH prevalence also varied significantly according to geographical location. No significant association was found with maternal age.

Early neonatal echocardiographic findings in an experimental rabbit model of congenital diaphragmatic hernia

This study aimed to demonstrate that congenital diaphragmatic hernia (CDH) results in vascular abnormalities that are directly associated with the severity of pulmonary hypoplasia and hypertension. These events increase right ventricle (RV) afterload and may adversely affect disease management and patient survival. Our objective was to investigate cardiac function, specifically right ventricular changes, immediately after birth and relate them to myocardial histological findings in a CDH model. Pregnant New Zealand rabbits underwent the surgical procedure at 25 days of gestation (n=14). CDH was created in one fetus per horn (n=16), and the other fetuses were used as controls (n=20). At term (30 days), fetuses were removed, immediately dried and weighed before undergoing four-parameter echocardiography. The lungs and the heart were removed, weighed, and histologically analyzed. CDH animals had smaller total lung weight (P<0.005), left lung weight (P<0.005), and lung-to-body ratio (P<0.005). Echocardiography revealed a smaller left-to-right ventricle ratio (LV/RV, P<0.005) and larger diastolic right ventricle size (DRVS, P<0.007). Histologic analysis revealed a larger number of myocytes undergoing mitotic division (186 vs 132, P<0.05) in CDH hearts. Immediate RV dilation of CDH hearts is related to myocyte mitosis increase. This information may aid the design of future strategies to address pulmonary hypertension in CDH.

Prevention of pulmonary hypoplasia and pulmonary vascular remodeling by antenatal simvastatin treatment in nitrofen-induced congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) has a high mortality rate mainly due to lung hypoplasia and persistent pulmonary hypertension of the newborn (PPHN). Simvastatin has been shown to prevent the development of pulmonary hypertension (PH) in experimental models of PH. We, therefore, hypothesized that antenatal simvastatin would attenuate PPHN in nitrofen-induced CDH in rats. The efficacy of antenatal simvastatin was compared with antenatal sildenafil, which has already been shown to improve pathological features of PPHN in nitrofen-induced CDH. On embryonic day (E) 9.5, nitrofen or vehicle was administered to pregnant Sprague-Dawley rats. On E11, nitrofen-treated rats were randomly assigned to antenatal simvastatin (20 mg·kg(-1)·day(-1) orally), antenatal sildenafil (100 mg·kg(-1)·day(-1) orally), or placebo administration from E11 to E21. On E21, fetuses were delivered by cesarean section, killed, and checked for left-sided CDH. Lung tissue was then harvested for further pathobiological evaluation. In nitrofen-induced CDH, simvastatin failed to reduce the incidence of nitrofen-induced CDH in the offspring and to increase the body weight, but improved the lung-to-body weight ratio and lung parenchyma structure. Antenatal simvastatin restored the pulmonary vessel density and external diameter, and reduced the pulmonary arteriolar remodeling compared with nitrofen-induced CDH. This was associated with decreased lung expression of endothelin precursor, endothelin type A and B receptors, endothelial and inducible nitric oxide synthase, together with restored lung activation of apoptotic processes mainly in the epithelium. Antenatal simvastatin presented similar effects as antenatal therapy with sildenafil on nitrofen-induced CDH. Antenatal simvastatin improves pathological features of lung hypoplasia and PPHN in experimental nitrofen-induced CDH.

Congenital diaphragmatic hernia may be associated with 17q12 microdeletion syndrome

Microdeletions of 17q12 encompassing TCF2 are associated with maturity-onset of diabetes of the young type 5, cystic renal disease, pancreatic atrophy, Mullerian aplasia in females and variable cognitive impairment. We report on a patient with a de novo 17q12 microdeletion, 1.8 Mb in size, associated with congenital diaphragmatic hernia (CDH). The 5-year-old male patient presented multicystic renal dysplasia kidneys, minor facial dysmorphic features and skeletal anomalies, but neither developmental delay nor behavioral abnormalities. CDH has been previously associated with the 17q12 microdeletion syndrome only in one prenatal case. The present study reinforces the hypothesis that CDH is part of the phenotype for 17q12 microdeletion and that 17q12 encompasses candidate(s) gene(s) involved in diaphragm development. We suggest that PIGW, a gene involved in an early step of GPI biosynthesis, could be a strong candidate gene for CDH.

Antenatal use of bosentan and/or sildenafil attenuates pulmonary features in rats with congenital diaphragmatic hernia

BACKGROUND

Lung hypoplasia, pulmonary persistent hypertension of the newborn and its morphological changes are the main features in congenital diaphragmatic hernia (CDH). This study was undertaken to investigate if antenatal use of sildenafil and/or bosentan attenuates vascular remodeling, promotes branching, and improves alveolarization in experimental nitrofeninduced CDH.

METHODS

Nitrofen (100 mg) was gavage-fed to pregnant rats at post conception day (PCD) 9 to induce CDH. The rats were randomized to 5 groups: 1) control; 2) nitrofen; 3) nitrofen+sildenafil 100 mg/kg per day at PCD 16-20; 4) nitrofen+bosentan 30 mg/kg per day, at PCD 16-20, and 5) nitrofen+bosentan+sildenafil, same doses and administration days. After cesarean delivery, the offsprings were sacrificed. The diaphragmatic defect and pulmonary hypoplasia were identified, and the lungs were dissected. Arterial wall thickness, bronchiolar density and alveolarization were assessed.

RESULTS

The offsprings with CDH were characterized by severe pulmonary hypoplasia (lung weight-to-body weight ratio: 0.0263 [95% confidence interval (CI) 0.0242-0.0278)] in the nitrofen group versus 0.0385 (95% CI 0.0355-0.0424) in the control group (P=0.0001). Pulmonary arterial wall thickness was decreased to 3.0 (95% CI 2.8-3.7) μm in the nitrofen+sildenafil group versus 5.0 (95% CI 4.1-4.9) μm in the nitrofen group (P=0.02). Terminal bronchioles increased to 13.7 (95% CI 10.7-15.2) μm in the nitrofen+bosentan group in contrast to 8.7 (95% CI 7.2-9.4) μm in the nitrofen group (P=0.002). More significant differences (P=0.0001) were seen in terminal bronchioles in the nitrofen+sildenafil+bosentan group than in the nitrofen group [14.0 (95% CI 12.5-15.4) μm versus 8.5 (95% CI 7.1-9.3) μm]. Pulmonary arterial wall thickness was also decreased in the former group.

CONCLUSIONS

In this rat model, antenatal treatment with sildenafil attenuates vascular remodeling. Bosentan promotes the development of terminal bronchioles in nitrofen-induced CDH.

Molecular pathogenesis of congenital diaphragmatic hernia revealed by exome sequencing, developmental data, and bioinformatics

Congenital diaphragmatic hernia (CDH) is a common and severe birth defect. Despite its clinical significance, the genetic and developmental pathways underlying this disorder are incompletely understood. In this study, we report a catalog of variants detected by a whole exome sequencing study on 275 individuals with CDH. Predicted pathogenic variants in genes previously identified in either humans or mice with diaphragm defects are enriched in our CDH cohort compared with 120 size-matched random gene sets. This enrichment was absent in control populations. Variants in these critical genes can be found in up to 30.9% of individuals with CDH. In addition, we filtered variants by using genes derived from regions of recurrent copy number variations in CDH, expression profiles of the developing diaphragm, protein interaction networks expanded from the known CDH-causing genes, and prioritized genes with ultrarare and highly disruptive variants, in 11.3% of CDH patients. These strategies have identified several high priority genes and developmental pathways that likely contribute to the CDH phenotype. These data are valuable for comparison of candidate genes generated from whole exome sequencing of other CDH cohorts or multiplex kindreds and provide ideal candidates for further functional studies. Furthermore, we propose that these genes and pathways will enhance our understanding of the heterogeneous molecular etiology of CDH.

Nontraumatic Liver Herniation through a Right–Sided Congenital Diaphragmatic Hernia of Morgagni: An Autopsy Case Report with a Review of Liver Herniations through the Defect and a Review of the Defect

Congenital diaphragmatic hernia of Morgagni (CMH) is a rare developmental defect that develops during the development of the human diaphragm. It is usually right-sided and tends to produce symptoms in later life when abdominal viscera herniate into the chest cavities.

Herniations of the liver through this defect into the chest cavities are rare and are often not clinically suspected even when they are associated with symptoms. The amounts of liver tissue involved are usually small, do not cause symptoms and are often an incidental finding during imaging studies of the chest for unrelated symptoms.

This case report documents a clinically unrecognized incidental herniation of the liver into the right chest cavity through a CMH. The report also reviews previously reported cases of liver herniations through a CMH and the possible causes of the defect.

Whole exome sequencing identifies de novo mutations in GATA6 associated with congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a common birth defect affecting 1 in 3000 births. It is characterised by herniation of abdominal viscera through an incompletely formed diaphragm. Although chromosomal anomalies and mutations in several genes have been implicated, the cause for most patients is unknown.

METHODS

We used whole exome sequencing in two families with CDH and congenital heart disease, and identified mutations in GATA6 in both.

RESULTS

In the first family, we identified a de novo missense mutation (c.1366C>T, p.R456C) in a sporadic CDH patient with tetralogy of Fallot. In the second, a nonsense mutation (c.712G>T, p.G238*) was identified in two siblings with CDH and a large ventricular septal defect. The G238* mutation was inherited from their mother, who was clinically affected with congenital absence of the pericardium, patent ductus arteriosus and intestinal malrotation. Deep sequencing of blood and saliva-derived DNA from the mother suggested somatic mosaicism as an explanation for her milder phenotype, with only approximately 15% mutant alleles. To determine the frequency of GATA6 mutations in CDH, we sequenced the gene in 378 patients with CDH. We identified one additional de novo mutation (c.1071delG, p.V358Cfs34*).

CONCLUSIONS

Mutations in GATA6 have been previously associated with pancreatic agenesis and congenital heart disease. We conclude that, in addition to the heart and the pancreas, GATA6 is involved in development of two additional organs, the diaphragm and the pericardium. In addition, we have shown that de novo mutations can contribute to the development of CDH, a common birth defect.

Identification of dosage-sensitive genes in fetuses referred with severe isolated congenital diaphragmatic hernia

OBJECTIVE

Congenital diaphragmatic hernia (CDH) is a fetal abnormality affecting diaphragm and lung development with a high mortality rate despite advances in fetal and neonatal therapy. CDH may occur either as an isolated defect or in syndromic form for which the prognosis is worse. Although conventional karyotyping and, more recently, chromosomal microarrays support a substantial role for genetic factors, causal genes responsible for isolated CDH remain elusive. We propose that chromosomal microarray analysis will identify copy number variations (CNVs) associated with isolated CDH.

METHODS

We perform a prospective genome-wide screen for CNVs using chromosomal microarrays on 75 fetuses referred with apparently isolated CDH, six of which were later reclassified as non-isolated CDH.

RESULTS

The results pinpoint haploinsufficiency of NR2F2 as a cause of CDH and cardiovascular malformations. In addition, the 15q25.2 and 16p11.2 recurrent microdeletions are associated with isolated CDH. By using gene prioritisation and network analysis, we provide strong evidence for several novel dosage-sensitive candidate genes associated with CDH.

CONCLUSIONS

Chromosomal microarray analysis detects submicroscopic CNVs associated with isolated CDH or CDH with cardiovascular malformations.

Downregulated bone morphogenetic protein signaling in nitrofen-induced congenital diaphragmatic hernia

PURPOSE

Bone morphogenetic proteins (BMP) have been shown to play crucial roles in not only lung and heart development, but also in the pathogenesis of pulmonary vascular remodeling in pulmonary hypertension (PH). We therefore hypothesized that BMP signaling could be altered in nitrofen-induced congenital diaphragmatic hernia (CDH) and associated PH.

METHODS

Pregnant rats were exposed to either 100 mg nitrofen or vehicle on embryonic day (E) 9.5. On E17 and E21, fetuses were delivered by cesarean section, killed and checked for left-sided CDH. The tissue was then harvested for pathobiological evaluation.

RESULTS

In nitrofen-induced CDH, pulmonary expressions of BMP4, BMP receptor (BMPR) type 2 and Id1 decreased on E17 and E21. On E17, pulmonary gremlin-1 expression increased, while BMP7 decreased. In the lungs, Id1 expression was correlated to BMP4 and BMPR2 and inversely correlated to gremlin-1 expression. Myocardial expressions of BMPR2, BMPR1A, BMP7 and SERCA-2A decreased, while gremlin-1 and noggin expressions increased on E17. On E21, myocardial expressions of Id1 and SERCA-2A decreased, while gremlin-1 expression increased. Moreover, BMPR2 and BMPR1A expressions were correlated to SERCA-2A expression and inversely correlated to pro-apoptotic Bax/Bcl2 ratio within the myocardium.

CONCLUSION

Downregulation of BMP signaling seems to contribute to pulmonary and myocardial anomalies observed in nitrofen-induced CDH.

Development of the diaphragm -- a skeletal muscle essential for mammalian respiration

The mammalian diaphragm muscle is essential for respiration, and thus is one of the most critical skeletal muscles in the human body. Defects in diaphragm development leading to congenital diaphragmatic hernias (CDH) are common birth defects and result in severe morbidity or mortality. Given its functional importance and the frequency of congenital defects, an understanding of diaphragm development, both normally and during herniation, is important. We review current knowledge of the embryological origins of the diaphragm, diaphragm development and morphogenesis, as well as the genetic and developmental aetiology of diaphragm birth defects.

De novo copy number variants are associated with congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a common birth defect with significant morbidity and mortality. Although the aetiology of CDH remains poorly understood, studies from animal models and patients with CDH suggest that genetic factors play an important role in the development of CDH. Chromosomal anomalies have been reported in CDH.

METHODS

In this study, the authors investigated the frequency of chromosomal anomalies and copy number variants (CNVs) in 256 parent-child trios of CDH using clinical conventional cytogenetic and microarray analysis. The authors also selected a set of CDH related training genes to prioritise the genes in those segmental aneuploidies and identified the genes and gene sets that may contribute to the aetiology of CDH.

RESULTS

The authors identified chromosomal anomalies in 16 patients (6.3%) of the series including three aneuploidies, two unbalanced translocation, and 11 patients with de novo CNVs ranging in size from 95 kb to 104.6 Mb. The authors prioritised the genes in the CNV segments and identified KCNA2, LMNA, CACNA1S, MYOG, HLX, LBR, AGT, GATA4, SOX7, HYLS1, FOXC1, FOXF2, PDGFA, FGF6, COL4A1, COL4A2, HOMER2, BNC1, BID, and TBX1 as genes that may be involved in diaphragm development. Gene enrichment analysis identified the most relevant gene ontology categories as those involved in tissue development (p=4.4×10(-11)) or regulation of multicellular organismal processes (p=2.8×10(-10)) and 'receptor binding' (p=8.7×10(-14)) and 'DNA binding transcription factor activity' (p=4.4×10(-10)).

CONCLUSIONS

The present findings support the role of chromosomal anomalies in CDH and provide a set of candidate genes including FOXC1, FOXF2, PDGFA, FGF6, COL4A1, COL4A2, SOX7, BNC1, BID, and TBX1 for further analysis in CDH.

Familial severe congenital diaphragmatic hernia: left herniation in one sibling and bilateral herniation in another

Familial congenital diaphragmatic hernia (CDH) is extremely rare; it comprises about 2% of all CDH cases. The empirical risk is about 2%, increasing to 10% in a family with two affected children. This report describes severe CDH in two siblings who had been diagnosed prenatally. The female newborn diagnosed with left CDH prenatally was born at 38 weeks of gestation. Despite surgical repair and intensive treatment, she died 10 days after birth. Her younger brother was born at 39 weeks of gestation after being diagnosed with bilateral CDH prenatally, and died 75 min after birth. Both infants had neither other congenital anomaly nor chromosomal abnormalities. Their parents are healthy without consanguinity. Their first daughter and the fourth child have no congenital anomalies.

An evidence-based review of the current treatment of congenital diaphragmatic hernia

Congenital diaphragmatic hernia is a rare but severe condition affecting 1 in 2000 to 3000 newborns with a survival rate of 67%. Although regular antenatal screening allows prenatal diagnosis in many cases, traditionally treatment has been based on postnatal surgical repair. Recent literature has pointed out the survival benefits of initial stabilization and the use of gentle ventilation strategies prior to definitive treatment, shifting the trend from immediate to delayed surgical repair. Advances in fetal intervention have allowed the introduction of fetal endoscopic tracheal occlusion as a method to hasten lung development before birth in order to minimize postnatal morbidity. Despite appropriate treatment, the long-term outcomes of these patients are plagued with numerous complications, associated with the primary pathology and also aggressive therapeutic measures. International centers of excellence have recently come together in an effort to standardize the care of such patients in hopes of maximizing their outcomes.

Papillary renal carcinoma arising in an ectopic native kidney and status after renal transplant: a report of a unique case and review of the literature

Renal ectopia is an uncommon developmental defect of upper urinary tract. Except for hydronephrosis and urinary calculus formation, it is believed that ectopic kidneys are not more susceptible to diseases compared to the normally positioned kidneys. Primary renal carcinoma in ectopic kidneys is rarely observed. Our literature review identified eight cases in nontransplanted patients; seven were clear-cell carcinoma and one was papillary renal carcinoma. On the other hand, native kidneys of renal transplant patients are fifteen times more likely to develop renal carcinoma than those of nontransplanted patients. Renal malignancy has never been reported in native ectopic kidneys of transplant recipients. We report the first case of a papillary renal carcinoma in a native ectopic kidney of a 30 year-old female, six-year status after renal transplantation.

Deficiency of FRAS1-related extracellular matrix 1 (FREM1) causes congenital diaphragmatic hernia in humans and mice

Congenital diaphragmatic hernia (CDH) is a common life-threatening birth defect. Recessive mutations in the FRAS1-related extracellular matrix 1 (FREM1) gene have been shown to cause bifid nose with or without anorectal and renal anomalies (BNAR) syndrome and Manitoba oculotrichoanal (MOTA) syndrome, but have not been previously implicated in the development of CDH. We have identified a female child with an isolated left-sided posterolateral CDH covered by a membranous sac who had no features suggestive of BNAR or MOTA syndromes. This child carries a maternally-inherited ~86 kb FREM1 deletion that affects the expression of FREM1's full-length transcripts and a paternally-inherited splice site mutation that causes activation of a cryptic splice site, leading to a shift in the reading frame and premature termination of all forms of the FREM1 protein. This suggests that recessive FREM1 mutations can cause isolated CDH in humans. Further evidence for the role of FREM1 in the development of CDH comes from an N-ethyl-N-nitrosourea -derived mouse strain, eyes2, which has a homozygous truncating mutation in Frem1. Frem1(eyes2) mice have eye defects, renal agenesis and develop retrosternal diaphragmatic hernias which are covered by a membranous sac. We confirmed that Frem1 is expressed in the anterior portion of the developing diaphragm and found that Frem1(eyes2) embryos had decreased levels of cell proliferation in their developing diaphragms when compared to wild-type embryos. We conclude that FREM1 plays a critical role in the development of the diaphragm and that FREM1 deficiency can cause CDH in both humans and mice.

Gastric volvulus complication in an infant with undiagnosed congenital diaphragmatic hernia presenting with acute respiratory distress

INTRODUCTION

Congenital diaphragmatic hernia is an embryologic defect that creates a passage for herniation of abdominal structures into the thoracic cavity. This can lead to a variety of complications, including gastric volvulus that can present acutely with epigastric distention and vomiting. In cases of late-onset congenital diaphragmatic hernia, symptoms may be vague and often necessitate further investigation.

CASE

Our patient is a 12-month-old previously healthy female infant who presented to the emergency department with a history of vomiting and acute onset respiratory distress. Her SaO(2) was 94% to 98% on room air, her respiratory rate was in the 80s breaths per minute, and she was noted to have severe retractions. Her chest examination revealed absent breath sounds on the left side. Her abdominal examination was unremarkable. The acute presentation of respiratory distress was initially concerning for a foreign body aspiration, but a chest radiograph demonstrated left-sided opacification and mediastinal shift to the right. The patient required intubation for respiratory decompensation and a subsequent computed tomographic scan showed diaphragmatic hernia with gastric volvulus.

CONCLUSIONS

This patient's presentation highlights one of the complications that may occur owing to congenital diaphragmatic hernia. Computed tomographic scan is the confirmatory test for diaphragmatic hernia and, in this case, also uncovered a concomitant gastric volvulus. Treatment includes early resuscitation, a definitive airway, and emergent surgery to prevent ischemic necrosis of the stomach owing to strangulation, gastric perforation, and serious cardiorespiratory decompensation.