Osteogenesis imperfecta (OI) is a rare but serious genetic disorder of bone leading to increased fragility and greatly increased susceptibility to fracture. Some patients experience additional problems such as abnormally formed teeth, progressive deafness and scoliosis. The condition is divided into various subtypes with types I and IV being the commonest, type 2 is lethal in utero and type 3 is associated with most disability and deformity. Patients with OI typically have a large number of fractures in childhood, a reduced number in early adulthood but there appears to be an exaggerated risk of fracture with increasing age. In the past, there was no treatment but children with the condition are now frequently treated with courses of i.v. bisphosphonates that increase the density of bone and improve mobility. It is far less clear how adult patients with OI should be managed. This is largely due to a lack of long-term data regarding the natural history of untreated OI. Additionally, there is some evidence in support of the use of bisphosphonates in adults with OI but it is unclear who these drugs should be targeted to (and when) and whether there are any long-term adverse effects associated with these drugs in such patients. Long-term use of bisphosphonates has been linked to atypical fractures, suppressed bone turnover and osteonecrosis of the jaw in patients with osteoporosis. Whether similar risks exist in patients with OI is unclear. To address these issues we recently developed a combined bone/clinical genetics clinic within the West Midlands. We have identified over 200 individuals with OI, the majority of which have not previously had specialist assessment as adults. This cohort will provide the basis for longitudinal observational studies relating to the natural history of treated and untreated OI.