[Analysis of clinical phenotype and genetic variant in a Chinese pedigree affected with cleidocranial dysplasia].

OBJECTIVE:To analyze the clinical features and pathogenic variant in a Chinese pedigree affected with cleidocranial dysplasia (CCD). METHODS:Clinical data of 8 patients from the pedigree was collected, including physical examination and X-ray images of head, face, spine, limbs, and mouth. Peripheral blood samples were collected from 6 affected members for the extraction of genomic DNA. The proband and other 3 patients were subjected to trio-whole exome sequencing. Candidate variant was verified by Sanger sequencing of the other 2 affected members from the pedigree. RESULTS:This pedigree has included 22 members (8 affected) from four generations. Genetic testing revealed that the proband has harbored a novel pathogenic variant of the RUNX2 gene [NM_001024630: c.1268_1277del (p.P425Afs*56)], which was inherited from her mother and carried by all affected members in the pedigree. The same variant was not detected among the unaffected members, suggesting co-segregation with the phenotype. CONCLUSION:The c.1268_1277del (p.P425Afs*56) variant of the RUNX2 gene probably underlay the pathogenesis of CCD in this pedigree. Genetic testing has facilitated the definite diagnosis and enabled prenatal diagnosis.