Abstract
We report rare twin babies with Osteogenesis imperfecta (OI) . Only 10 other cases of twins with OI have reported. One twin died within 1 h and the other within 12 h after birth ; both were autopsied. Autosomal recessive inheritance was comfirmed by their pedigree chart. These cases were classified into type II of Scillence's classification. They showed characteristic physical features : short and round extrimities and soft skull with diastasis of the sutures. Autopsy of the babies revealed membranous skull bone, bone fractures and thin cortex of tubular bones. Pulmonary hypoplasia and congestive edema with massive aspiration syndrome became the cause of death. Microscopically, the skull bone were fibrous tissue with scattered ossification centers, and the metaphysis and diaphyseal cortex of the femoral bone were insufficiently ossified. An ultrastructure study has revealed that collagenous fibers do not make up the bundles, although controls show so called interweaving fibrous bundles.
