Brittle bone disease or Osteogenesis Imperfecta (OI) is a rare bone disease. It is a genetic disorder which results in defects in the protein called collagen that is responsible for making stronger bones. Children suffering from the diseases have weaker bones that are susceptible to fractures. Collagen is the building brick of every tissue in the body, not just the bones. So in addition to fractures, there may be muscle weakness, joint laxity, spinal deformities, stunted growth, lung disease, teeth abnormalities, eye problems, deafness etc.
There are mainly eight types of the disease. Type I is the commonest type where the child may have only a few fractures during childhood and may have insignificant impact. Type II is a very severe form of OI where most children do not survive because of the inability to withstand trauma of delivery. These children have multiple intrauterine fractures and often do not survive. Type III is a severe form in which mobility is significantly impaired.
There is no single diagnostic test to confirm the disease. Clinical symptoms and some radiological tests can help diagnosis. Molecular and genetic tests help verify whether the mutation is present in the gene coding for collagen. Ultrasound during pregnancy can help diagnose Type II disease. The disease has no cure. Bisphosphonates, a group of drugs that prevents bone loss, decrease the frequency and severity of fractures. A rodding surgery is often required to stabilise the weaker bones. Scientists have developed a new method to treat brittle bone disease in children using the medicine risedronate. It can not only reduce the risk of fracture but also have rapid action.