A case of Japanese cleidocranial dysplasia with a CBFA1 frameshift mutation

Cleidocranial dysplasia (CCD), which is caused by mutations of the core bin ding factor alpha 1 (CBFA1)/runt-related gene 2 (Runx2), is an autosomal, d ominantly inherited disorder of high penetrance affecting skeletal ossifica tion and tooth development. Recently, we found a novel frameshift mutation 383-T-insertion (S128F) in exon 3 in the CBFA1 gene of a Japanese classic C CD patient. We describe our detailed investigation of the patient with CCD associated with the CBFA 1 mutation. The patient showed the characteristic expression of CCD, such as dysplasia of the clavicles, patent fontanelles, short stature, impacted supernumerary teeth, and delayed eruption of the pe rmanent teeth. In addition to these characteristics, orthopantomography del ayed ossification of the mandibular symphysis and a three-dimensional compu ted tomograph (3D-CT) analysis showed hypoplasia of the zygomatic arch. Fur thermore, the acellular cementum of an impacted supernumerary tooth was abs ent in this patient. Thus, the CBFA1 mutation was critical for the pathogen esis of CCD in this patient.