Heterogeneity of osteogenesis imperfecta type I.

We have studied 166 patients from 71 families with Sillence type I osteogenesis imperfecta (dominant inheritance and blue sclerae). We confirm earlier findings that there are two subgroups, those with and those without dentinogenesis imperfecta; each family can be allocated to one or other group. Our confidence that the two groups represent distinct disorders is increased by finding that the patients with dentinogenesis imperfecta differ not only in their dental characteristics but also in other clinical features. They have a more severe disease with a greater fracture rate and a greater likelihood of growth impairment.