The brittle bone syndrome; an update

Abstract

Abstract Many recent books still give old-fashioned accounts of osteogenesis imperfecta (OI). The current classification, which is based on Sillence 8 and is derived from clinical, genetic and more recently biochemical studies, identifies four main types (Table 1). It replaces previous divisions into OI congenita (fractures before birth) and OI tarda; it defines prognosis, and it aids appropriate treatment. The effects of the collagen gene mutations which cause the OI syndrome are modified by their nature, by their position within the collagen molecule, by mosaicism, by tissue expression and by treatment, so that considerable variability occurs in OI patients within families as well as between different families. In the great majority of OI subjects, including perinatal lethal (type II) OI, the collagen gene mutation behaves as an autosomal dominant. The most important differential diagnosis is from non-accidental injury. 9 Management of the OI patient should involve several disciplines and includes correct genetic advice. The most frequent surgery involves the insertion of rods into the long bones; current work emphasizes the possible therapeutic benefits of bisphosphonates; and specialized rehabilitation by those with an experience in OI is essential.