Diagnosing osteogenesis imperfecta

Osteogenesis imperfecta (OI) encompasses a group of rare heritable disorders associated with low bone mass and increased susceptibility to fractures. The vast majority of cases are the result of disturbances in type 1 collagen production. Classification is on the basis of severity although some particular types have been defined by characteristic clinical and histopathological findings or according to the location of underlying mutations.Diagnosis is usually clinical. History should include attention to fractures, back pain, motor development and family background. Examination should focus on the skeleton, including the spine, and on identifying other features which support the diagnosis, including scleral hue, teeth and ligamentous laxity. However, there may be few physical findings to support the diagnosis in mild cases.Investigations, including plain radiography, transiliac bone biopsy and genetic analyses, can help support or confirm the diagnosis. Other conditions are associated with increased bone fragility in childhood; particular difficulties with diagnosis can occur in the antenatal setting or in cases of suspected non-accidental injury.The importance of childhood in terms of bone mass acquisition and spinal growth as well as the scope for dramatically improved outcomes with timely intervention all highlight the importance of accurate and prompt diagnosis of OI.