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.
Congenital diaphragmatic hernia (CDH) is a common birth defect that is associated with significant morbidity and mortality, especially when associated with additional congenital anomalies. Both environmental and genetic factors are thought to contribute to CDH. The genetic contributions to CDH are highly heterogeneous and incompletely defined. No one genetic cause accounts for more than 1-2% of CDH cases. In this review, we summarize the known genetic causes of CDH from chromosomal anomalies to individual genes. Both de novo and inherited variants contribute to CDH. Genes causing CDH are increasingly identified from animal models and from genomic strategies including exome and genome sequencing in humans. CDH genes are often transcription factors, genes involved in cell migration or the components of extracellular matrix. We provide clinical genetic testing strategies in the clinical evaluation that can identify a genetic cause in up to ~30% of patients with non-isolated CDH and can be useful to refine prognosis, identify associated medical and neurodevelopmental issues to address, and inform family planning options.
Purpose
Congenital diaphragmatic hernia (CDH) is associated with significant mortality and long-term morbidity in some but not all individuals. We hypothesize monogenic factors that cause CDH are likely to have pleiotropic effects and be associated with worse clinical outcomes.
Methods
We enrolled and prospectively followed 647 newborns with CDH and performed genomic sequencing on 462 trios to identify
de novo
variants. We grouped cases into those with and without likely damaging (LD) variants and systematically assessed CDH clinical outcomes between the genetic groups.
Results
Complex cases with additional congenital anomalies had higher mortality than isolated cases (
P
=8×10
−6
). Isolated cases with LD variants had similar mortality to complex cases and much higher mortality than isolated cases without LD (
P
=3×10
−3
). The trend was similar with pulmonary hypertension at 1 month. Cases with LD variants had an estimated 12–17 points lower scores on neurodevelopmental assessments at 2 years compared to cases without LD variants, and this difference is similar in isolated and complex cases.
Conclusion
We found that the LD genetic variants are associated with higher mortality, worse pulmonary hypertension, and worse neurodevelopment outcomes compared to non-LD variants. Our results have important implications for prognosis, potential intervention and long-term follow up for children with CDH.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.