Background
Cleidocranial dysplasia (CCD) is a rare genetic disorder affecting bone and cartilage development. Clinical features of CCD comprise short stature, delayed ossification of craniofacial structures with numerous Wormian bones, underdeveloped or aplastic clavicles and multiple dental anomalies. Several studies have revealed that CCD development is strongly linked with different mutations in Runt-related Transcription Factor 2 (RUNX2) gene. In this study, we report a case with typical CCD presentations.
Methods
We performed genetic testing of participants and found a novel RUNX2 frameshift mutation: c.1550delT in a sporadic case. We also compared the functional activity of the mutant and wild-type RUNX2 through immunofluorescence microscopy and osteocalcin promoter luciferase assay.
Results
Both mutant RUNX2 and wild‑type RUNX2 protein were similarly confined in the nuclei. The novel mutation caused abrogative transactivation activity of RUNX2 on osteocalcin promoter.
Conclusions
We explored a novel RUNX2 deletion/frameshift mutation in a sporadic CCD patient. This finding emphasizes on crucial role of VWRPY domain in RUNX2 transactivation ability.