Objective To analyze the mutations of the RUNX2 gene in a family with cleidocranial dysplasia (CCD).Methods The general health status of family members with CCD was investigated through propositus verification method. Oral specialized examination and radiological examination were performed. The peripheral venous blood of the proband and her parents and sisters was collected. Genomic DNA was extracted, and the RUNX2 gene from this DNA was amplified by polymerase chain reaction (PCR). DNA sequences were analyzed with the Blastn program.Results After Blastn analysis, heterozygous C to T transition mutation at nucleotide 568 occurred in exon 2, which converted arginine to tryptophane at codon 190 (c.568C>T, CGG→TGG).Conclusion RUNX2 gene is responsible for the CCD in the Chinese family under study. The c.568C>T mutation is the molecular basis of the CCD in the family.
