DefinitionOsteogenesis imperfecta is a condition causing extremely fragile bones.Alternative NamesBrittle bone diseaseCauses, incidence, and risk factorsOsteogenesis imperfecta (OI) is a congenital disease, meaning it is present at birth. It is frequently caused by defect in the gene that produces type 1 collagen, an important building block of bone. There are many different defects that can affect this gene. The severity of OI depends on the specific gene defect.OI is an autosomal dominant disease. That means if you have one copy of the gene, you will have the disease. Most cases of OI are inherited from a parent, although some cases are the result of new genetic mutations.A person with OI has a 50% chance of passing on the gene and the disease to their children.SymptomsAll people with OI