Background Evidence for periconceptional or prenatal environmental risk factors for the development of congenital diaphragmatic hernia (CDH) is still scarce. Here, in a case-control study we investigated potential environmental risk factors in 199 CDH patients compared to 597 healthy control newborns. Methods The following data was collected: time of conception and birth, maternal BMI, parental risk factors such as smoking, alcohol or drug intake, use of hairspray, contact to animals and parental chronic diseases. CDH patients were born between 2001 and 2019, all healthy control newborns were born in 2011. Patients and control newborns were matched in the ratio of three to one. Results Presence of CDH was significantly associated with maternal periconceptional alcohol intake (odds ratio = 1.639, 95% confidence interval 1.101–2.440, p = 0.015) and maternal periconceptional use of hairspray (odds ratio = 2.072, 95% confidence interval 1.330–3.229, p = 0.001). Conclusion Our study suggests an association between CDH and periconceptional maternal alcohol intake and periconceptional maternal use of hairspray. Besides the identification of novel and confirmation of previously described parental risk factors, our study underlines the multifactorial background of isolated CDH.

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Congenital diaphragmatic hernia (CDH) is a congenital structural anomaly in which the diaphragm has not developed properly. It may occur either as an isolated anomaly or with additional anomalies. It is thought to be a multifactorial disease in which genetic factors could either substantially contribute to or directly result in the developmental defect. Patients with aneuploidies, pathogenic variants or de novo Copy Number Variations (CNVs) impacting specific genes and loci develop CDH typically in the form of a monogenetic syndrome. These patients often have other associated anatomical malformations. In patients without a known monogenetic syndrome, an increased genetic burden of de novo coding variants contributes to disease development. In early years, genetic evaluation was based on karyotyping and SNP-array. Today, genomes are commonly analyzed with next generation sequencing (NGS) based approaches. While more potential pathogenic variants are being detected, analysis of the data presents a bottleneck—largely due to the lack of full appreciation of the functional consequence and/or relevance of the detected variant. The exact heritability of CDH is still unknown. Damaging de novo alterations are associated with the more severe and complex phenotypes and worse clinical outcome. Phenotypic, genetic—and likely mechanistic—variability hampers individualpatient diagnosis, short and long-term morbidity prediction and subsequent care strategies. Detailed phenotyping, clinical follow-up at regular intervals and detailed registries are needed to find associations between long-term morbidity, genetic alterations, and clinical parameters. Since CDH is a relatively rare disorder with only a few recurrent changes large cohorts of patients are needed to identify genetic associations. Retrospective whole genome sequencing of historical patient cohorts using will yield valuable data from which today's patients and parents will profit Trio whole genome sequencing has an excellent potential for future re-analysis and data-sharing increasing the chance to provide a genetic diagnosis and predict clinical prognosis. In this review, we explore the pitfalls and challenges in the analysis and interpretation of genetic information, present what is currently known and what still needs further study, and propose strategies to reap the benefits of genetic screening.

Background The mortality of neonates with congenital diaphragmatic hernia (CDH) ranges between 20 and 40% even in specialized high-volume centers. The Score for Neonatal Acute Physiology-II (SNAP-II Score) could facilitate the decision about supportive therapies in CDH newborns. Methods The SNAP-II score consists of the variables arterial blood pressure, pH, PaO2:FiO2, body temperature, diuresis, and seizure activity and was calculated at an age of 12 h. Results 101 CDH newborns treated in our institution between 2009 and 2017 were included in the study. A SNAP-II score ≥ 28 was calculated as cutoff for predicting mortality (AUC 0.876; 95% CI: 0.795–0.957). The mortality rate was 52.9% with a SNAP-II score ≥ 28, and 5.9% with a SNAP-II score<28. Sensitivity and specificity for predicting mortality was 81.8 and 79.7%, the negative predicting value (NPV) was 94.0%, the positive predicting value (PPV) 52.9%. The optimal cutoff for predicting ECMO was ≥ 22 (AUC 0.895; 95% CI: 0.836–0.954). Sensitivity and specificity for predicting ECMO therapy was 90.7, and 63.8%, the NPV was 90.2%, and the PPV was 65% respectively. The SNAP-II score was independently associated with mortality [OR 1.126 (95% CI: 1.050–1.207)] and the need for ECMO therapy [OR 1.243 (95% CI: 1.106–1.397)]. Conclusion The SNAP-II score is strongly associated with mortality and the need for ECMO therapy in CDH newborns and should be implemented in the risk stratification of these infants.

Background The acronym VATER/VACTERL association describes the combination of at least three component features (CFs): vertebral defects (V), anorectal malformations (ARM) (A), cardiac defects (C), tracheoesophageal fistula with or without esophageal atresia (TE), renal malformations (R), and limb defects (L). Individuals presenting two CFs have been termed VATER/VACTERL‐like. Recently, FOXF1, HSPA6, HAAO, KYNU, TRAP1, and ZIC3 have been proposed as candidate genes for VATER/VACTERL, VATER/VACTERL‐like, and ARM. Re‐sequencing studies identified disease‐causing variants in TRAP1 and ZIC3, the contribution of other genes was not independently investigated. One affected variant carrier in FOXF1 was previously identified. Here we re‐sequenced FOXF1, HSPA6, HAAO, and KYNU in 522 affected individuals. Methods Using molecular inversion probe (MIP) technology, re‐sequencing was performed in 63 individuals with VATER/VACTERL association, 313 with VATER/VACTERL‐like association, and 146 with ARM. All individuals were of European ethnicity. Variant filtering considered variants with a minor allele frequency (MAF) ≤0.01 for putative recessive disease‐genes HSPA6, HAAO, and KYNU. For the putative dominant disease‐gene FOXF1 we considered variants with a MAF ≤0.0001. In silico prediction tools were used for further prioritization. Results Only two variants in FOXF1 in two independently affected individuals [c.443G>T, p.(Cys148Phe); c.850T>C, p.(Tyr284His)] passed our filter criteria. One individual presented with ARM, the second presented with TE and C comprising atrial and ventricular septal defects. Sanger sequencing confirmed both variants but also their inheritance from the healthy mother. Conclusion Our analysis suggests that FOXF1, HSPA6, HAAO and KYNU do not play a major role in the formation of VACTER/VACTERL phenotypes or ARM.

The genetic etiology of congenital diaphragmatic hernia (CDH), a common and severe birth defect, is still incompletely understood. Chromosomal aneuploidies, copy number variations (CNVs), and variants in a large panel of CDH-associated genes, both de novo and inherited, have been described. Due to impaired reproductive fitness, especially of syndromic CDH patients, and still significant mortality rates, the contribution of de novo variants to the genetic background of CDH is assumed to be high. This assumption is supported by the relatively low recurrence rate among siblings. Advantages in high-throughput genome-wide genotyping and sequencing methods have recently facilitated the detection of de novo variants in CDH. This review gives an overview of the known de novo disease-causing variants in CDH patients.

Anorectal malformations (ARM) represent a spectrum of rare malformations originating from a perturbated development of the embryonic hindgut. Approximately 60% occur as a part of a defined genetic syndrome or within the spectrum of additional congenital anomalies. Rare copy number variations (CNVs) have been associated with both syndromic and non-syndromic forms. The present study represents the largest study to date to explore the contribution of CNVs to the expression of ARMs. SNP-array-based molecular karyotyping was applied in 450 individuals with ARM and 4392 healthy controls. CNVs were identified from raw intensity data using PennCNV. Overlapping CNVs between cases and controls were discarded. Remaining CNVs were filtered using a stringent filter algorithm of nine filter steps. Prioritized CNVs were confirmed using qPCR. Filtering prioritized and qPCR confirmed four microscopic chromosomal anomalies and nine submicroscopic CNVs comprising seven microdeletions (del2p13.2, del4p16.2, del7q31.33, del9p24.1, del16q12.1, del18q32, del22q11.21) and two microduplications (dup2p13.2, dup17q12) in 14 individuals (12 singletons and one affected sib-pair). Within these CNVs, based on their embryonic expression data and function, we suggest FOXK2, LPP, and SALL3 as putative candidate genes. Overall, our CNV analysis identified putative microscopic and submicroscopic chromosomal rearrangements in 3% of cases. Functional characterization and re-sequencing of suggested candidate genes is warranted.

Congenital diaphragmatic hernia (CDH) is a relatively common and severe birth defect with variable clinical outcome and associated malformations in up to 60% of patients. Mortality and morbidity remain high despite advances in pre-, intra-, and postnatal management. We review the current literature and give an overview about the genetics of CDH to provide guidelines for clinicians with respect to genetic diagnostics and counseling for families. Until recently, the common practice was (molecular) karyotyping or chromosome microarray if the CDH diagnosis is made prenatally with a 10% diagnostic yield. Undiagnosed patients can be reflexed to trio exome/genome sequencing with an additional diagnostic yield of 10 to 20%. Even with a genetic diagnosis, there can be a range of clinical outcomes. All families with a child with CDH with or without additional malformations should be offered genetic counseling and testing in a family-based trio approach.