summary Cleidocranial Dysplasia is a rare congenital disorder caused by an autosomal dominant mutation in the RUNX2/CBFA1 gene leading to abnormal intramembranous ossification. Patients present with proportionate dwarfism with the characteristic feature of hypoplastic or absent clavicles. Diagnosis is made based on family history associated with typical radiographic and clinical features. No commercially available diagnostic test exists due to the variety of genetic mutations. Treatment involves a multidisciplinary approach to improve and maintain function with observation of clavicular hypoplasia. Epidemiology Incidence approximately 1 in 1,000,000 affected Etiology Pathophysiology caused by defect in intramembranous ossification leads to failure of formation of midline structures characteristic feature is hypoplastic or absent clavicles Genetics autosomal dominant RUNX2/CBFA1 mutation transcription factor which regulates osteoblastic differentiation Orthopaedic manifestations proportionate dwarfism clavicle dysplasia/aplasia wormian bones frontal bossing delayed fontanelle ossification due to delay in closure of skull sutures coxa vara shortened middle phalanges of 3-5 fingers delayed ossification of pubis dental abnormalities delayed eruption of permanent teeth Presentation Symptoms usually asymptomatic Physical exam hypermobility of the shoulders frontal bossing hand deformities examine middle phalanges for shortening delayed formation of permanent teeth abnormal range of motion at hips if severe coxa vara may be present Imaging Radiographs recommended AP chest to identify clavicular dysmorphism lateral skull look for delayed closure of sutures AP pelvis look for coxa vara look for failure of pubis to ossify AP hands short middle phalanges Treatment Nonoperative observation indications clavicular hypoplasia outcomes most manifestations associated with this disease do not need intervention Operative intertrochanteric osteotomy indications coxa vara with a neck shaft angle of less than 100 degrees