The most severe form of osteogenesis imperfecta. Infants are usually born with multiple fractures, an unusually soft skull, an unstable neck and are quite small. Almost all infants with Type II OI die at or shortly after birth, often due to respiratory problems. In the newborn period, it can be difficult to distinguish between Type II and severe type III OI. Very rare exceptions of true Type II infants with longer survival have been reported.