Described here are two patients with a newly recognized syndrome of bone and cartilage maldevelopment which, we believe, results from a single embryonic defect, probably of genetic origin. The cardinal manifestations of this association are craniosynostosis, radiohumeral synostosis (RHS), and femoral bowing. Specific secondary defects include midface hypoplasia with characteristic facial appearance and ears, neonatal femoral fractures, and multiple minor anomalies of the limbs. Though the differential diagnosis includes such disorders as the campomelic syndrome, osteogenesis imperfecta (OI) and certain of acrocephalosyndactyly syndromes, the unique combination of clinical and radiographic abnormalities allows ready differentiation. The cause cannot be determined from these two cases.