Biology of RUNX2 and Cleidocranial Dysplasia

Three features of cleidocranial dysplasia that are not always appreciated are hypoplastic iliac wings, short stature, and brachydactyly. Because of the pelvic abnormality, pregnant women may require a cesarean delivery. Short stature and brachydactyly indicate more generalized skeletal abnormalities. These are derived from endochondral and intramembranous ossification, but the distinction between these 2 processes is oversimplified because both processes are involved in long bone and clavicular development. Two sections follow: the biology of RUNX2 and the nature of haploinsufficiency in RUNX2 mutations for cleidocranial dysplasia.