Deficiency Directly Leads to Systemic and Craniofacial Skeletal Abnormalities.

The gene encodes Rho-GTPase-activating protein 29 (), which plays a crucial role in embryonic tissue development. Mutations in the gene are significantly associated with non-syndromic cleft lip and palate (NSCL/P). Our study demonstrated that the deletion of leads to syndromic cleft lip and palate (SCL/P) characteristics in mice, where, in addition to cleft palate, the mice exhibit craniofacial and systemic skeletal abnormalities. However, the mechanisms underlying these skeletal abnormalities remain unclear. Through micro-CT imaging, histological analysis, and transcriptomic methods, we discovered that the knockout of delays the fusion of Meckel's cartilage, widens cranial sutures, reduces bone quality, and alters the expression of osteoblasts and osteoclasts in the mandible. Digit defects, including ectrodactyly and impaired endochondral ossification, were also observed. Immunohistochemical analysis demonstrated the expression of in both osteoblasts and osteoclasts, indicating its dual role in maintaining matrix homeostasis and regulating bone resorption equilibrium. Transcriptomic analysis revealed disrupted calcium and MAPK signaling pathways, while in vitro studies demonstrated impaired osteogenesis in -deficient calvarial cells, mirroring the in vivo defects. Furthermore, spatial transcriptomics linked the loss of to defective bone differentiation and protein synthesis. Our findings underscore the critical role of in the development of the mandible and digits, suggesting its potential as a pathogenic gene associated with syndromic cleft lip and palate (SCL/P).