[Prenatal diagnosis for two families affected with cleidocranial dysplasia due to novel RUNX2 variants].

OBJECTIVE: To analyze variants of RUNX2 gene in two pedigrees affected with cleidocranial dysplasia and provide prenatal diagnosis for them. METHODS: For the two probands, the coding sequences of the RUNX2 gene were analyzed with PCR and bidirectional Sanger sequencing. To verify the results, peripheral blood samples were collected from their parents and 100 healthy controls. For family 1, umbilical cord blood was also collected for prenatal genetic diagnosis. RESULTS: In family 1, the proband and the fetus both carried a heterozygous c.578G>C (p.Arg193Pro) mutation. For family 2, the proband was found to carry a heterozygous c.909C>A (p.Tyr303X) mutation. The same mutations were not found among their parents and 100 healthy controls. Neither mutation was reported previously. CONCLUSION: Variants of the RUNX2 gene probably underlie the cleidocranial dysplasia in both pedigrees. The results enabled prenatal diagnosis for the affected family.