by Kimberly Allen R.N.
The term osteogenesis imperfecta (OI) covers a group of genetic disorders that mostly affect the bones. The name osteogenesis imperfecta literally means imperfect bone formation. Ostoegenesis imperfecta or OI is also referred to as brittle bone disease. It is estimated that 20,000 to 50,000 people have OI in the US. OI has always been considered an autosomal dominant disorder howwever, in recent years autosomal recessive types have been identified also.
Osteogenesis imperfecta is caused by a genetic mutation that occurs in the gene responsible for telling our body to make collagen. Collagen is a protein that is needed to help support the body. There are several different types of collagen in our bodies, however type I is the most prevalent. Type I collagen is the protein found in bone, ligaments, teeth and the sclera of the eyes.
OI develops when there is a problem with the production of type I collagen. There are currently eight different types of OI defined as type 1-8. Of the 8 type I is the most common. In type I the quality of the collagen is normal, however it is not being made in sufficient quantity. This causes the bones to fracture easily, poor muscle tone and there’s also usually a blue-gray tint to the sclera. In type II the collagen is neither of sufficient quality or quantity and unfortunately most diagnosed with the type die with in the first year. Type III occurs when there is enough collagen, but it is defective. This type is also referred to as the “progressive deformity” type. Type IV is opposite type I in that there is enough collagen but the quality is poor causing the bones to fracture easily. Type V presents with the same clinical signs as type IV, however under futher examination there is a mesh-like appearance to the bone. In type V there is a hardening of the membrane between the ulna and radius, the two bones that are the forearm. Type VI also presents like type IV however when examined further the bone has afish scale appearance. Type VII was discovered in 2006 and is a recessive type of osteogenesis imperfecta. Type VIII also recently discovered is caused by a mutation in a different gene known as LEPREI.
The symptoms of OI can range from mild to severe, they vary from person to person though there are some symptoms that are common to all including bones that are malformed and break easily. Most people with OI are shorter with loose joints and muscle weakness. The sclera in their eyes have a bluish-gray tint and they frequently suffer from hearing loss.
There is no cure for OI at this time however, there are therapies that are used to reduce the pain and complications of the disorder. Medications used to treat osteoporosis known as biophosphonates have shown significant promise in treating OI, especially in children. Participating in low impact exercises like swimming improves both muscle and bone strength. Surgery can be used in the more severe cases to place metal rods into the long bones of the legs to help strengthen them and decrease the risk of fracture. Reconstructive surgery can correct any deformities associated with OI.
There is no way to prevent OI but you can limit many of the complications associated with OI by eating a healthy diet high in calcium and vitamin D as well as foods high in antioxidants and exercising regularly. Avoiding activities that can cause injury like playing football helps limit bone fracture and injury. Children with OI often become fearful of trying new things because they are afraid of breaking a bone, this can lead to isolation and depression. There are several Osteogenesis Imperfecta foundations available that can help families cope with the challenges of OI.
Kimberly Allen is a registered nurse with an AND in nursing. She has worked in ACF, LCF and psychiatric facilities, although she spent most of her career as a home health expert. She is now a regular contributor to HealthAndFitnessTalk.com, dispensing advice and knowledge about medical issues and questions. You can reach her with any comments or questions at firstname.lastname@example.org.