CTBP1与碱性磷酸酶协同变异通过Wnt信号受损导致下颌发育不全：一个寡基因模型

Craniofacial malformations account for one third of all congenital anomalies. Genetic factors play a vital role, yet the list of causal genes and their mechanisms are far from complete. As part of a larger effort to sequence patients with micrognathia and Pierre-Robin sequence, we identified two candidate pathogenic missense variants in C-terminal binding protein 1 ( CTBP1 ) along with a heterozygous early stop missense variant in alkaline phosphatase ( ALPL ) in a proband with mandibular hypoplasia. Ctbp1 has been shown to regulate Wnt/β-Catenin signaling but it has not yet been implicated in craniofacial development. Here we generated two orthologous variants of Ctbp1 mimicking the patient variants using genome editing in mice and explored the micrognathia phenotype in combination with a previously reported Alpl null allele. Ctbp1 Q148H/G238S ; Alpl null/Wt complex heterozygous mutants have smaller mandibles recapitulating the human mandibular hypoplasia. We identified that a reduction in cell proliferation and active β-Catenin levels could possibly account for the micrognathia phenotype in the Ctbp1 ; Alpl complex heterozygous. These data uncover a novel role for Ctbp1 in craniofacial development and highlight the complex genetic and molecular signaling in the pathogenesis of craniofacial malformations.