Decreased ß-catenin Protein in Lungs From Human Congenital Diaphragmatic Hernia Archival Pathology Specimens: A Case-control Study.

BACKGROUND: Lung hypoplasia contributes to congenital diaphragmatic hernia (CDH) associated morbidity and mortality. Changes in lung wingless-type MMTV integration site family member (Wnt)-signalling and its downstream effector beta-catenin (CTNNB1), which acts as a transcription coactivator, exist in animal CDH models but are not well characterized in humans. We aim to identify changes to Wnt-signalling gene expression in human CDH lungs and hypothesize that pathway expression will be lower than controls. METHODS: We identified 51 CDH cases and 10 non-CDH controls with archival formalin-fixed paraffin-embedded (FFPE) autopsy lung tissue from 2012 to 2022. 11 liveborn CDH cases and an additional two anterior diaphragmatic hernias were excluded from the study, leaving 38 CDH cases. Messenger ribonucleic acid (mRNA) expression of Wnt-signalling effectors WNT2B and CTNNB1 was determined for 19 CDH cases and 9 controls. A subset of CDH cases and controls lung sections were immunostained for ß-catenin. Clinical variables were obtained from autopsy reports. RESULTS: Median gestational age was 21 weeks. 81% (n = 31) of hernias were left-sided. 47% (n = 18) were posterolateral. Liver position was up in 81% (n = 31) of cases. Defect size was Type C or D in 58% (n = 22) of cases based on autopsy photos, and indeterminable in 42% (n = 16) of cases. WNT2B and CTNNB1 mRNA expression did not differ between CDH and non-CDH lungs. CDH lungs had fewer interstitial cells expressing ß-catenin protein than non-CDH lungs (13.2% vs 42.4%; p = 0.006). CONCLUSION: There appear to be differences in the abundance and/or localization of ß-catenin proteins between CDH and non-CDH lungs. LEVEL OF EVIDENCE: Level III. TYPE OF STUDY: Case-Control Study.

Review of the Evaluation of Pulmonary Hypoplasia as an Important Determinant of Clinical Outcomes in Infants with Congenital Diaphragmatic Hernia.

Pulmonary hypoplasia is one of main causes of neonatal mortality and morbidity in patients with congenital diaphragmatic hernia. With most cases diagnosed prenatally, the emphasis is put on prediction of the severity of this defect. Several attempts are made to reduce the mortality and provide optimal prenatal and postnatal care. Appropriate estimation of risk of pulmonary hypoplasia also provides an important inclusion criterion for prenatal intervention. The main tool used for the detection and prediction of pulmonary hypoplasia is ultrasound, with an increasing number of available formulas to estimate the risk of occurrence of this phenomenon and complication associated with it. For most of the formulas used in this measurement method, the main limitations are either gestational-age dependency or limited research. Other imaging methods used to assess the risk of pulmonary hypoplasia involve magnetic resonance imaging and vascular assessment of affected lungs. The limitation in these remains the limited accessibility. Currently, the most widely used indexes are observed-to-expected lungs-to-head ratio and presence of liver herniation. These are the 2 most commonly used measurement methods, as they are the basis for patient qualification for fetoscopic endoluminal tracheal occlusion. This article aims to review the evaluation of pulmonary hypoplasia or hypoplastic lung disease as an important determinant of clinical outcomes in infants with congenital diaphragmatic hernia. In this review, we emphasize the importance of early prenatal diagnosis of congenital diaphragmatic hernia and present a summary of different methods of prenatal risk assessment of lung hypoplasia in congenital diaphragmatic hernia.

Rescuing lung development through embryonic inhibition of histone acetylation.

A major barrier to the impact of genomic diagnosis in patients with congenital malformations is the lack of understanding regarding how sequence variants contribute to disease pathogenesis and whether this information could be used to generate patient-specific therapies. Congenital diaphragmatic hernia (CDH) is among the most common and severe of all structural malformations; however, its underlying mechanisms are unclear. We identified loss-of-function sequence variants in the epigenomic regulator gene SIN3A in two patients with complex CDH. Tissue-specific deletion of Sin3a in mice resulted in defects in diaphragm development, lung hypoplasia, and pulmonary hypertension, the cardinal features of CDH and major causes of CDH-associated mortality. Loss of SIN3A in the lung mesenchyme resulted in reduced cellular differentiation, impaired cell proliferation, and increased DNA damage. Treatment of embryonic Sin3a mutant mice with anacardic acid, an inhibitor of histone acetyltransferase, reduced DNA damage, increased cell proliferation and differentiation, improved lung and pulmonary vascular development, and reduced pulmonary hypertension. These findings demonstrate that restoring the balance of histone acetylation can improve lung development in the Sin3a mouse model of CDH.

Pathological findings in congenital diaphragmatic hernia on necropsy studies: A single-center case series.

INTRODUCTION: Congenital diaphragmatic hernia (CDH) is associated with high mortality rates and significant pulmonary morbidities. The objective of this study was to delineate the histopathological features observed in necropsies of CDH patients and correlate these with their clinical manifestations. METHODS: We retrospectively reviewed the postmortem findings and corresponding clinical characteristics in eight CDH cases from 2017 to July 2022. RESULTS: The median survival time was 46 (8-624) hours. Autopsy reports showed that diffuse alveolar damage (congestion and hemorrhage) and hyaline membrane formation were the primary pathological lung changes observed. Notably, despite significant reduction in lung volume, the lung development appeared normal in 50% of the cases, while lobulated deformities were present in three (37.5%) cases. All patients displayed a large patent ductus arteriosus (PDA) and a patent foramen ovale, resulting in increased right ventricle (RV) volume, and myocardial fibers appeared slightly congested and swollen. The pulmonary vessels indicated thickening of the arterial media and adventitia. Lung hypoplasia and diffuse lung damage resulted in impaired gas exchange, while PDA and pulmonary hypertension led to RV failure, subsequent organ dysfunction and ultimately death. CONCLUSIONS: Patients with CDH typically succumb to cardiopulmonary failure, a condition driven by a complex interplay of pathophysiological factors. This complexity accounts for the unpredictable response to currently available vasodilators and ventilation therapies.

Single-cell transcriptomic profiling of microvascular endothelial cell heterogeneity in congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is a neonatal anomaly that includes pulmonary hypoplasia and hypertension. We hypothesized that microvascular endothelial cell (EC) heterogeneity is different in CDH lungs and related to lung underdevelopment and remodeling. To test this, we evaluated rat fetuses at E21.5 in a nitrofen model of CDH to compare lung transcriptomes among healthy controls (2HC), nitrofen-exposed controls (NC) and nitrofen-exposed subjects with CDH. Single-cell RNA sequencing with unbiased clustering revealed 3 distinct microvascular EC clusters: a general population (mvEC), a proliferative population and a population high in hemoglobin. Only the CDH mvEC cluster had a distinct inflammatory transcriptomic signature as compared to the 2HC and NC endothelial cells, e.g. greater activation and adhesion of inflammatory cells and production of reactive oxygen species. Furthermore, CDH mvECs had downregulated Ca4, Apln and Ednrb gene expression. Those genes are markers for ECs important to lung development, gas exchange and alveolar repair (mvCa4+). mvCa4+ ECs were reduced in CDH (2HC [22.6%], NC [13.1%] and CDH [5.3%], p < 0.0001). Overall, these findings identify transcriptionally distinct microvascular endothelial cell clusters in CDH, including the distinctly inflammatory mvEC cluster and the depleted group of mvCa4+ ECs, which together may contribute to pathogenesis.

The myocardial capillary network is altered in congenital diaphragmatic hernia in the fetal rabbit model.

Congenital diaphragmatic hernia (CDH) is associated with thoracic compression of the lungs and heart caused by the herniated abdominal content, leading to cardiac modifications including pressure and vascular changes. Our aim was to investigate the experimental immunoexpression of the capillary proliferation, activation, and density of Ki-67, VEGFR2, and lectin in the myocardium after surgical creation of a diaphragmatic defect. Pregnant New Zealand rabbits were operated on the 25th gestational day in order to create left-sided CDH (LCDH, n=9), right-sided CDH (RCDH, n=9), and Control (n=9), for a total of 27 fetuses in 19 pregnant rabbits. Five days after the procedure, animals were sacrificed, and histology and immunohistochemistry studies of the harvested hearts were performed. Total body weight and heart weight were not significantly different among groups (P=0.702 and 0.165, respectively). VEGFR2 expression was increased in both ventricles in the RCDH group (P<0.0001), and Ki-67 immunoexpression was increased in the left ventricle in the LCDH group compared to Control and RCDH groups (P<0.0001). In contrast, capillary density was reduced in the left ventricle in the LCDH compared to the Control and RCDH groups (P=0.002). Left and right ventricles responded differently to CDH in this model depending on the laterality of the diaphragmatic defect. This surgical model of diaphragmatic hernia was associated with different expression patterns of capillary proliferation, activation, and density in the myocardium of the ventricles of newborn rabbits.

The metabolic and lipidomic profiling of the effects of tracheal occlusion in a rabbit model of congenital diaphragmatic hernia.

PURPOSE: Fetal tracheal occlusion (TO) reverses the pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH), but its mechanism of action remains poorly understood. 'Omic' readouts capture metabolic and lipid processing function, which aid in understanding CDH and TO metabolic mechanisms. METHODS: CDH was created in fetal rabbits at 23 days, TO at 28 days and lung collection at 31 days (Term ∼32 days). Lung-body weight ratio (LBWR) and mean terminal bronchiole density (MTBD) were determined. In a cohort, left and right lungs were collected, weighed, and samples homogenized, and extracts collected for non-targeted metabolomic and lipidomic profiling via LC-MS and LC-MS/MS, respectively. RESULTS: LBWR was significantly lower in CDH while CDH + TO was similar to controls (p = 0.003). MTBD was significantly higher in CDH fetuses and restored to control and sham levels in CDH + TO (p < 0.001). CDH and CDH + TO resulted in significant differences in metabolome and lipidome profiles compared to sham controls. A significant number of altered metabolites and lipids between the controls and CDH groups and the CDH and CDH + TO fetuses were identified. Significant changes in the ubiquinone and other terpenoid-quinone biosynthesis pathway and the tyrosine metabolism pathway were observed in CDH + TO. CONCLUSION: CDH + TO reverses pulmonary hypoplasia in the CDH rabbit, in association with a specific metabolic and lipid signature. A synergistic untargeted 'omics' approach provides a global signature for CDH and CDH + TO, highlighting cellular mechanisms among lipids and other metabolites, enabling comprehensive network analysis to identify critical metabolic drivers in disease pathology and recovery. TYPE OF STUDY: Basic Science, Prospective. LEVEL OF EVIDENCE: II.

The role of genes and environment in the etiology of congenital diaphragmatic hernias.

Structural birth defects are a common cause of abnormalities in newborns. While there are cases of structural birth defects arising due to monogenic defects or environmental exposures, many birth defects are likely caused by a complex interaction between genes and the environment. A structural birth defect with complex etiology is congenital diaphragmatic hernias (CDH), a common and often lethal disruption in diaphragm development. Mutations in more than 150 genes have been implicated in CDH pathogenesis. Although there is generally less evidence for a role for environmental factors in the etiology of CDH, deficiencies in maternal vitamin A and its derivative embryonic retinoic acid are strongly associated with CDH. However, the incomplete penetrance of CDH-implicated genes and environmental factors such as vitamin A deficiency suggest that interactions between genes and environment may be necessary to cause CDH. In this review, we examine the genetic and environmental factors implicated in diaphragm and CDH development. In addition, we evaluate the potential for gene-environment interactions in CDH etiology, focusing on the potential interactions between the CDH-implicated gene, Gata4, and maternal vitamin A deficiency.

Brain development is altered in rabbit fetuses with congenital diaphragmatic hernia.

INTRODUCTION: Children with congenital diaphragmatic hernia (CDH) are at risk for neurodevelopmental delay. Some changes are already present prenatally. Herein, we further examined how the brain develops in fetal rabbits with surgically created DH. METHODS: Two fetuses underwent surgical DH creation on day 23 (term = d31). DH pups and littermate controls were harvested at term. Ten DH pups and 11 controls underwent transcardial perfusion for brain fixation and measurement of brain volume, brain folding, neuron and synaptic density, pre-oligodendrocyte count, proliferation, and vascularization. Twelve other DH and 11 controls had echocardiographic assessment of cardiac output and aortic and cerebral blood flow, magnetic resonance imaging (9.4 T) for cerebral volumetry, and molecular assessment of vascularization markers. RESULTS: DH pups had lower lung-to-body weight ratio (1.3 ± 0.3 vs. 2.4 ± 0.3%; p < 0.0001) and lower heart-to-body weight ratio (0.007 ± 0.001 vs. 0.009 ± 0.001; p = 0.0006) but comparable body weight and brain-to-body weight ratio. DH pups had a lower left ventricular ejection fraction, aortic and cerebral blood flow (39 ± 8 vs. 54 ± 15 mm/beat; p = 0.03) as compared to controls but similar left cardiac ventricular morphology. Fetal DH-brains were similar in volume but the cerebellum was less folded (perimeter/surface area: 25.5 ± 1.5 vs. 26.8 ± 1.2; p = 0.049). Furthermore, DH brains had a thinner cortex (143 ± 9 vs. 156 ± 13 µm; p = 0.02). Neuron densities in the white matter were higher in DH fetuses (124 ± 18 vs. 104 ± 14; p = 0.01) with comparable proliferation rates. Pre-oligodendrocyte count was lower, coinciding with the lower endothelial cell count. CONCLUSION: Rabbits with DH had altered brain development compared to controls prenatally, indicating that brain development is already altered prenatally in CDH.

Assessment of the fetal lungs in utero.

Antenatal diagnosis of abnormal pulmonary development has improved significantly over recent years because of progress in imaging techniques. Two-dimensional ultrasound is the mainstay of investigation of pulmonary pathology during pregnancy, providing good prognostication in conditions such as congenital diaphragmatic hernia; however, it is less validated in other high-risk groups such as those with congenital pulmonary airway malformation or preterm premature rupture of membranes. Three-dimensional assessment of lung volume and size is now possible using ultrasound or magnetic resonance imaging; however, the use of these techniques is still limited because of unpredictable fetal motion, and such tools have also been inadequately validated in high-risk populations other than those with congenital diaphragmatic hernia. The advent of advanced, functional magnetic resonance imaging techniques such as diffusion and T2* imaging, and the development of postprocessing pipelines that facilitate motion correction, have enabled not only more accurate evaluation of pulmonary size, but also assessment of tissue microstructure and perfusion. In the future, fetal magnetic resonance imaging may have an increasing role in the prognostication of pulmonary abnormalities and in monitoring current and future antenatal therapies to enhance lung development. This review aims to examine the current imaging methods available for assessment of antenatal lung development and to outline possible future directions.

Evidence for an association between Coffin-Siris syndrome and congenital diaphragmatic hernia.

Coffin-Siris syndrome (CSS) is an autosomal dominant neurodevelopmental syndrome that can present with a variety of structural birth defects. Pathogenic variants in 12 genes have been shown to cause CSS. Most of these genes encode proteins that are a part of the mammalian switch/sucrose non-fermentable (mSWI/SNF; BAF) complex. An association between genes that cause CSS and congenital diaphragmatic hernia (CDH) has been suggested based on case reports and the analysis of CSS and CDH cohorts. Here, we describe an unpublished individual with CSS and CDH, and we report additional clinical information on four published cases. Data from these individuals, and a review of the literature, provide evidence that deleterious variants in ARID1B, ARID1A, SMARCB1, SMARCA4, SMARCE1, ARID2, DPF2, and SMARCC2, which are associated with CSS types 1-8, respectively, are associated with the development of CDH. This suggests that additional genetic testing to identify a separate cause of CDH in an individual with CSS may be unwarranted, and that comprehensive genetic testing for individuals with non-isolated CDH should include an evaluation of CSS-related genes. These data also suggest that the mSWI/SNF (BAF) complex may play an important role in diaphragm development.

The fetal lamb model of congenital diaphragmatic hernia shows altered cerebral perfusion using contrast enhanced ultrasound.

BACKGROUND: Neurodevelopmental impairment is common in survivors of congenital diaphragmatic hernia (CDH). Altered cerebral perfusion in utero may contribute to abnormal brain development in CDH patients. METHODS: 5 fetal lambs with surgical left-CDH and 5 controls underwent transuterine cranial Doppler and contrast enhanced ultrasound (CEUS). Global and regional perfusion metrics were obtained. Biometric and perfusion data were compared between groups via nonparametric Mann Whitney U test and Spearman's rank order correlation. RESULTS: No significant differences in cerebral Doppler measurements were identified between groups. By CEUS, CDH animals demonstrated significantly decreased global brain perfusion and increased transit time. With focal regions-of-interest (ROIs), there was a tendency towards decreased perfusion in the central/thalamic region in CDH but not in the peripheral brain parenchyma. Transit time was significantly increased in both ROIs in CDH, whereas flux rate was decreased in the central/thalamic region but not the peripheral brain parenchyma. Biometric CDH severity was correlated to perfusion deficit. There was no difference in cardiomyocyte histology. CONCLUSION: The fetal lamb model of CDH shows altered cerebral perfusion as measured by CEUS, correlating to disease severity. This suggests a physiological abnormality in fetal cerebrovascular perfusion that may contribute to abnormal brain development and neurodevelopmental impairment in survivors.

Fetal lung regeneration using stem cell-derived extracellular vesicles: A new frontier for pulmonary hypoplasia secondary to congenital diaphragmatic hernia.

The poor outcomes of babies with congenital diaphragmatic hernia (CDH) are directly related to pulmonary hypoplasia, a condition characterized by impaired lung development. Although the pathogenesis of pulmonary hypoplasia is not fully elucidated, there is now evidence that CDH patients have missing or dysregulated microRNAs (miRNAs) that regulate lung development. A prenatal therapy that supplements these missing/dysregulated miRNAs could be a strategy to rescue normal lung development. Extracellular vesicles (EVs), also known as exosomes when of small dimensions, are lipid-bound nanoparticles that can transfer their heterogeneous cargo (proteins, lipids, small RNAs) to target cells to induce biological responses. Herein, we review all studies that show evidence for stem cell-derived EVs as a regenerative therapy to rescue normal development in CDH fetal lungs. Particularly, we report studies showing that administration of EVs derived from amniotic fluid stem cells (AFSC-EVs) to models of pulmonary hypoplasia promotes fetal lung growth and maturation via transfer of miRNAs that are known to regulate lung developmental processes. We also describe that stem cell-derived EVs exert effects on vascular remodeling, thus possibly preventing postnatal pulmonary hypertension. Finally, we discuss future perspectives and challenges to translate this promising stem cell EV-based therapy to clinical practice.

Cubilin-, megalin-, and Dab2-dependent transcription revealed by CRISPR/Cas9 knockout in kidney proximal tubule cells.

The multiligand receptors megalin (Lrp2) and cubilin (Cubn) and their endocytic adaptor protein Dab2 (Dab2) play essential roles in maintaining the integrity of the apical endocytic pathway of proximal tubule (PT) cells and have complex and poorly understood roles in the development of chronic kidney disease. Here, we used RNA-sequencing and CRISPR/Cas9 knockout (KO) technology in a well-differentiated cell culture model to identify PT-specific transcriptional changes that are directly consequent to the loss of megalin, cubilin, or Dab2 expression. KO of Lrp2 had the greatest transcriptional effect, and nearly all genes whose expression was affected in Cubn KO and Dab2 KO cells were also changed in Lrp2 KO cells. Pathway analysis and more granular inspection of the altered gene profiles suggested changes in pathways with immunomodulatory functions that might trigger the pathological changes observed in KO mice and patients with Donnai-Barrow syndrome. In addition, differences in transcription patterns between Lrp2 and Dab2 KO cells suggested the possibility that altered spatial signaling by aberrantly localized receptors contributes to transcriptional changes upon the disruption of PT endocytic function. A reduction in transcripts encoding sodium-glucose cotransporter isoform 2 was confirmed in Lrp2 KO mouse kidney lysates by quantitative PCR analysis. Our results highlight the role of megalin as a master regulator and coordinator of ion transport, metabolism, and endocytosis in the PT. Compared with the studies in animal models, this approach provides a means to identify PT-specific transcriptional changes that are directly consequent to the loss of these target genes.NEW & NOTEWORTHY Megalin and cubilin receptors together with their adaptor protein Dab2 represent major components of the endocytic machinery responsible for efficient uptake of filtered proteins by the proximal tubule (PT). Dab2 and megalin expression have been implicated as both positive and negative modulators of kidney disease. We used RNA sequencing to knock out CRISPR/Cas9 cubilin, megalin, and Dab2 in highly differentiated PT cells to identify PT-specific changes that are directly consequent to knockout of each component.

Prenatal Molecular Hydrogen Administration Ameliorates Several Findings in Nitrofen-Induced Congenital Diaphragmatic Hernia.

Oxidative stress plays a pathological role in pulmonary hypoplasia and pulmonary hypertension in congenital diaphragmatic hernia (CDH). This study investigated the effect of molecular hydrogen (H2), an antioxidant, on CDH pathology induced by nitrofen. Sprague-Dawley rats were divided into three groups: control, CDH, and CDH + hydrogen-rich water (HW). Pregnant dams of CDH + HW pups were orally administered HW from embryonic day 10 until parturition. Gasometric evaluation and histological, immunohistochemical, and real-time polymerase chain reaction analyses were performed. Gasometric results (pH, pO2, and pCO2 levels) were better in the CDH + HW group than in the CDH group. The CDH + HW group showed amelioration of alveolarization and pulmonary artery remodeling compared with the CDH group. Oxidative stress (8-hydroxy-2'-deoxyguanosine-positive-cell score) in the pulmonary arteries and mRNA levels of protein-containing pulmonary surfactant that protects against pulmonary collapse (surfactant protein A) were significantly attenuated in the CDH + HW group compared with the CDH group. Overall, prenatal H2 administration improved respiratory function by attenuating lung morphology and pulmonary artery thickening in CDH rat models. Thus, H2 administration in pregnant women with diagnosed fetal CDH might be a novel antenatal intervention strategy to reduce newborn mortality due to CDH.

Rare and de novo variants in 827 congenital diaphragmatic hernia probands implicate LONP1 as candidate risk gene.

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly that is often accompanied by other anomalies. Although the role of genetics in the pathogenesis of CDH has been established, only a small number of disease-associated genes have been identified. To further investigate the genetics of CDH, we analyzed de novo coding variants in 827 proband-parent trios and confirmed an overall significant enrichment of damaging de novo variants, especially in constrained genes. We identified LONP1 (lon peptidase 1, mitochondrial) and ALYREF (Aly/REF export factor) as candidate CDH-associated genes on the basis of de novo variants at a false discovery rate below 0.05. We also performed ultra-rare variant association analyses in 748 affected individuals and 11,220 ancestry-matched population control individuals and identified LONP1 as a risk gene contributing to CDH through both de novo and ultra-rare inherited largely heterozygous variants clustered in the core of the domains and segregating with CDH in affected familial individuals. Approximately 3% of our CDH cohort who are heterozygous with ultra-rare predicted damaging variants in LONP1 have a range of clinical phenotypes, including other anomalies in some individuals and higher mortality and requirement for extracorporeal membrane oxygenation. Mice with lung epithelium-specific deletion of Lonp1 die immediately after birth, most likely because of the observed severe reduction of lung growth, a known contributor to the high mortality in humans. Our findings of both de novo and inherited rare variants in the same gene may have implications in the design and analysis for other genetic studies of congenital anomalies.

Management of Congenital Diaphragmatic Hernia (CDH): Role of Molecular Genetics.

Congenital diaphragmatic hernia (CDH) is a relatively common major life-threatening birth defect that results in significant mortality and morbidity depending primarily on lung hypoplasia, persistent pulmonary hypertension, and cardiac dysfunction. Despite its clinical relevance, CDH multifactorial etiology is still not completely understood. We reviewed current knowledge on normal diaphragm development and summarized genetic mutations and related pathways as well as cellular mechanisms involved in CDH. Our literature analysis showed that the discovery of harmful de novo variants in the fetus could constitute an important tool for the medical team during pregnancy, counselling, and childbirth. A better insight into the mechanisms regulating diaphragm development and genetic causes leading to CDH appeared essential to the development of new therapeutic strategies and evidence-based genetic counselling to parents. Integrated sequencing, development, and bioinformatics strategies could direct future functional studies on CDH; could be applied to cohorts and consortia for CDH and other birth defects; and could pave the way for potential therapies by providing molecular targets for drug discovery.

Isolated congenital diaphragm hernia associated with homozygous SLIT3 gene variant in dizygous twins.

Congenital diaphragmatic hernia (CDH) is a serious life-threatening birth defect characterized by abnormal development in the muscular or tendinous portion of the diaphragm during embryogenesis. Despite its high incidence, the etiology of CDH hasn't been fully understood. Genetic factors are important in pathogenesis; however, few single genes have been definitively implicated in human CDH. SLIT1, SLIT2, and SLIT3 (slit guidance ligand) are three human homologs of the drosophila Slit gene. They interact with roundabout (Robo) homolog receptors to affect cell migration, adhesion, cell motility, and angiogenesis and play important roles in cell signaling pathways including the guidance of axons. In this report, we presented dizygous twin babies with CDH related to the SLIT3 gene variant. Previous studies showed that Slit3 null mice had congenital diaphragmatic hernias on or near the ventral midline portion of the central tendon. This is the first report of homozygous SLIT3 variant associated with CDH in humans.

Computed tomography based measurements to evaluate lung density and lung growth after congenital diaphragmatic hernia.

Emphysema-like-change of lung is one aspect of lung morbidity in children after congenital diaphragmatic hernia (CDH). This study aims to evaluate if the extent of reduced lung density can be quantified through pediatric chest CT examinations, if side differences are present and if emphysema-like tissue is more prominent after CDH than in controls. Thirty-seven chest CT scans of CDH patients (mean age 4.5 ± 4.0 years) were analyzed semi-automatically and compared to an age-matched control group. Emphysema-like-change was defined as areas of lung density lower than - 950 HU in percentage (low attenuating volume, LAV). A p-value lower than 0.05 was regarded as statistically significant. Hypoattenuating lung tissue was more frequently present in the ipsilateral lung than the contralateral side (LAV 12.6% vs. 5.7%; p < 0.0001). While neither ipsilateral nor contralateral lung volume differed between CDH and control (p > 0.05), LAV in ipsilateral (p = 0.0002), but not in contralateral lung (p = 0.54), was higher in CDH than control. It is feasible to quantify emphysema-like-change in pediatric patients after CDH. In the ipsilateral lung, low-density areas are much more frequently present both in comparison to contralateral and to controls. Especially the ratio of LAV ipsilateral/contralateral seems promising as a quantitative parameter in the follow-up after CDH.

Decreased neonatal morbidity in 'stomach-down' left congenital diaphragmatic hernia: implications of prenatal ultrasound diagnosis for counseling and postnatal management.

OBJECTIVE: To evaluate the influence of stomach position on postnatal outcome in cases of left congenital diaphragmatic hernia (CDH) without liver herniation, diagnosed and characterized on prenatal ultrasound (US), by comparing those with ('stomach-up' CDH) to those without ('stomach-down' CDH) intrathoracic stomach herniation. METHODS: Infants with left CDH who underwent prenatal US and postnatal repair at our institution between January 2008 and March 2017 were eligible for inclusion in this retrospective study. Detailed prenatal US examinations, fetal magnetic resonance imaging (MRI) studies, operative reports and medical records of infants enrolled in the pulmonary hypoplasia program at our institution were reviewed. Cases with liver herniation and those with an additional anomaly were excluded. Cases in which bowel loops were identified within the fetal chest on US while the stomach was intra-abdominal were categorized as having stomach-down CDH. Cases in which bowel loops and the stomach were visualized within the fetal chest on US were categorized as having stomach-up CDH. Prenatal imaging findings and postnatal outcomes were compared between the two groups. RESULTS: In total, 152 patients with left CDH were initially eligible for inclusion. Seventy-eight patients had surgically confirmed liver herniation and were excluded. Of the 74 included CDH cases without liver herniation, 28 (37.8%) had stomach-down CDH and 46 (62.2%) had stomach-up CDH. Of the 28 stomach-down CDH cases, 10 (35.7%) were referred for a suspected lung lesion. Sixty-eight (91.9%) cases had postnatal outcome data available for analysis. There was no significant difference in median observed-to-expected (o/e) lung-area-to-head-circumference ratio (LHR) between cases with stomach-down CDH and those with stomach-up CDH (41.5% vs 38.4%; P = 0.41). Furthermore, there was no difference in median MRI o/e total lung volume (TLV) between the two groups (49.5% vs 44.0%; P = 0.22). Compared with stomach-up CDH patients, stomach-down CDH patients demonstrated lower median duration of intubation (18 days vs 9.5 days; P < 0.01), median duration of extracorporeal membrane oxygenation (495 h vs 223.5 h; P < 0.05), rate of supplemental oxygen requirement at 30 days of age (20/42 (47.6%) vs 3/26 (11.5%); P < 0.01) and rate of pulmonary hypertension at initial postnatal echocardiography (28/42 (66.7%) vs 9/26 (34.6%); P = 0.01). No neonatal death occurred in stomach-down CDH patients and one neonatal death was seen in a patient with intrathoracic stomach herniation. CONCLUSIONS: In infants with left CDH without liver herniation, despite similar o/e-LHR and o/e-TLV, those with stomach-down CDH have decreased neonatal morbidity compared to those with stomach herniation. Progressive or variable physiological distension of the stomach over the course of gestation may explain these findings. Stomach-down left CDH is mistaken for a lung mass in a substantial proportion of cases. Accurate prenatal US characterization of CDH is crucial for appropriate prenatal counseling and patient management. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.