CCD is a skeletal dysplasia that ranges from classical CCD (dental abnormalities, hypoplastic/aplastic clavicles, and delayed closure of cranial sutures) to mild CCD to isolated dental anomalies without the skeletal features.[10] Among the 202 registered RUNX2 variants (HGMD Professional 2020.4 http://www.hgmd.cf.ac.uk/), 99% (201/202) cause classical CCD. Here, RUNX2 is linked to skeletal dysplasia.