A novel RUNX2 splice site mutation in Chinese associated with cleidocranial dysplasia

Area of Science:

• Genetics
• Molecular Biology
• Developmental Biology

Background:

• Cleidocranial dysplasia (CCD) is primarily caused by mutations in the RUNX2 gene.
• RUNX2 is crucial for osteoblast differentiation and regulates bone development, including skull ossification and suture fusion.

Purpose of the Study:

• To investigate the role of RUNX2 mutations in a Chinese patient presenting with typical CCD symptoms.
• To characterize a novel splice site mutation in the RUNX2 gene.

Main Methods:

• Sanger sequencing was performed on peripheral blood samples from the proband and her mother.
• Digital PCR (dPCR) was utilized to quantify RUNX2 expression levels.
• RNA secondary structure prediction was employed to assess the impact of the mutation.

Main Results:

• A novel splice site mutation (C.685+5G>A) in intron 5 of the RUNX2 gene was identified in the proband.
• The mutation rate in the proband was 53%, while her mother was unaffected.
• The mutation altered the predicted secondary RNA structure of RUNX2, increasing free energy and decreasing stability.

Conclusions:

• This case report documents a rare RUNX2 splice site mutation in a Chinese population with CCD.
• The findings contribute to the understanding of RUNX2 mutation diversity and its role in CCD pathogenesis.
• This discovery enriches the RUNX2 mutation database for CCD-related genes in Chinese individuals.