Bone fragility, craniosynostosis, ocular proptosis, hydrocephalus, and distinctive facial features: a newly recognized type of osteogenesis imperfecta.

We report two infants with bone deformities and multiple fractures reminiscent of osteogenesis imperfecta, but also having ocular proptosis with orbital craniosynostosis, hydrocephalus, and distinctive facial features. Both infants were normal at birth, but multiple compression fractures of the long bones were noted shortly thereafter, followed by extensive demineralization and culminating in recurrent diaphyseal fractures of the weight-bearing bones before the first birthday. The striking similarity of both the distinctive dysmorphic features and the unique pattern of fractures in two unrelated individuals suggests that this is a previously unrecognized form of osteogenesis imperfecta. Despite the craniosynostosis and hydrocephalus, intellectual performance is unimpaired in both individuals. Bone biopsy in one patient revealed decreased bone volume and increased bone resorption without compensatory new bone formation. Extensive laboratory investigations have not identified a cause, nor have they clarified pathogenesis; further elucidation will require the identification and study of new cases.