Modeling patient variants of Cnot1 and Cdc42bpb lead to distinct forms of congenital diaphragmatic hernia in mice

ABSTRACT: Congenital diaphragmatic hernia (CDH) is a common and severe congenital anomaly characterized by disruption of the diaphragm and impairment of lung development in utero. CDH presents as a spectrum of forms and severities, with diaphragm disruptions arising in the dorsal/posterior region correlating with more severe pulmonary disease and higher risk of mortality than those appearing in ventral/anterior regions, which can present asymptomatically. The genetic etiology underlying CDH is complex, with many genes implicated showing variable expressivity and incomplete penetrance in both human patients and mouse models. Here we present in vivo validation of two genes previously unassociated with CDH: the CDC42-interacting kinase CDC42BPB; and CNOT1, a scaffolding protein of the CCR4-NOT protein complex, critical for mRNA regulation through modifications such as deadenylation. Each gene was found to have a damaging, de novo missense variant in a recent large-scale CDH patient sequencing screen. Loss of Cdc42bpb leads to ventral diaphragmatic hernia, heart septal defects and minor lung epithelial differentiation defects in mouse embryos. Installation of the orthologous patient missense variant through CRISPR/Cas9 editing leads to less severe ventral diaphragm defects. Mouse embryos with either one or two copies of the orthologous Cnot1 variant, c.1867C>T (p.R623W), develop dorsal diaphragmatic hernias with low (<50%) penetrance, and mutants showed alterations in mRNA isoform expression consistent with the molecular role of Cnot1 in RNA splicing. Taken together, these results underscore the power of in vivo functional modeling and reveal two previously unrecognized genetic drivers of diaphragm development and CDH pathogenesis.

ORGANISM(S): Mus musculus

PROVIDER: GSE318891 | GEO | 2026/08/12

REPOSITORIES: GEO