Objective: Cleidocranial dysplasia (CCD) is a rare skeletal disease with autosomal dominant inheritance associated with mutation in RUNX 2. The authors report a Chinese girl with CCD in whom the mutation in RUNX 2 was identified.
Methods: Clinical diagnosis was based on physical examination, radiological findings, and biochemical tests. For mutation detection, genomic DNA was extracted from peripheral blood using standard method. All 7 coding exons of RUNX 2 and their flanking intronic sequences were amplified by polymerase chain reaction (PCR), and the PCR products were then subjected to automatic DNA sequencing.
Results: The affected girl showed typical clinical manifestations of CCD, including patent fontanelles, absent clavicles, short stature and dental anomalies. Direct sequencing of PCR-amplified fragments revealed a recurrent missense mutation, R190W (568 C > T), in RUNX 2. The mutation was further confirmed by Hae III restriction analysis.
Conclusion: A Chinese case of CCD was confirmed and the disease-causing mutation was linked to a recurrent point mutation in RUNX 2.