Identification of a Novel Mutation in the Runt-Related Transcription Factor 2 Gene in a Chinese Family With Cleidocranial Dysplasia

ABSTRACT

Cleidocranial dysplasia (CCD) is an uncommon autosomal dominant disease, characterized by hypoplasia of clavicles, delayed fontanelle closure, dental anomalies, and short stature. It has been reported in the literature that the pathogenic variants of Runt-related transcription factor 2 (RUNX2) gene are correlated with CCD patients.Here, we report a consanguineous Chinese family with 2 patients suffering from CCD, presenting similar skeleton and dentition malformation. Upon whole-exome sequencing, 52863 variants were detected in the propositus. Based on the genotype phenotype correlation, a frameshift deletion c.1554delG p.(Trp518Cysfs∗61), located in exon 8 of RUNX2, remained after filtration. For Sanger sequencing, all exons of the RUNX2 gene in members of this Chinese family were amplified by polymerase chain reaction. Mutation mentioned above was confirmed in the propositus and his mother, which has not been reported previously and cannot be found in the publicly available databases. The present study expands the pathogenic variant spectrum of RUNX2 gene and contributes to molecular diagnosis.

Identification of a novel RUNX2 gene mutation and early diagnosis of CCD in a cleidocranial dysplasia suspected Iranian family

This research resulted in the identification and submission of a novel RUNX2 gene mutation in the affected members of the studied pedigree. Mutation screening is an effective method for the early diagnosis of CCD in the affected individuals.

Three-dimensional evaluation of morphology and position of impacted supernumerary teeth in cases of cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is a congenital anomaly characterized by the presence of impacted supernumerary teeth and delayed eruption of permanent teeth. However, there has been no detailed investigation on supernumerary teeth in patients with CCD using three-dimensional (3D) imaging techniques. The purpose of this study was to elucidate the morphology and position of supernumerary teeth using 3D images reconstructed from cone-beam computed tomography (CBCT) data in a group of five Japanese subjects (male, 3; female, 2; age, 15.0-25.4 years) with CCD. All five subjects exhibited supernumerary teeth (39 in total; average, 7.8; range, 1-15). All supernumerary teeth were impacted and existed as pairs with adjacent permanent teeth. Comparison of the size (the crown and dental-root lengths, the crown mesiodistal and buccolingual diameters), the number of cusps and dental roots, the position, and direction of supernumerary teeth in relation to the adjacent permanent teeth was analyzed. The results of relationship analyses revealed that, at sites other than the molar region, supernumerary teeth were positioned on the lingual and distal sides and supernumerary teeth resembled the morphology of their adjacent permanent teeth in terms of the number of cusps but were smaller than the adjacent permanent teeth. In the molar region, supernumerary teeth were microdontia, which were apparently small and obscure morphologically. In addition, while all adjacent permanent teeth exhibited normal direction, five supernumerary teeth exhibited inverse direction. The findings of this study will improve our understanding of the characteristics of CCD and provide important information for the pathophysiology and clinical treatment.