Osteogenesis Imperfecta (OI) is a group of genetic disorders that mainly affect the bones. The term "osteogenesis imperfecta" means imperfect bone formation. Alternate Names: Osteogenesis Imperfecta Congenita (OIC), Vrolik Disease (OI Type 2A) or Lobstein syndrome
People with this condition have bones that break easily, often from mild trauma or with no apparent cause. Multiple fractures are common, and in severe cases, can occur even before birth. Milder cases may involve only a few fractures over a person's lifetime.
There are at least eight recognized forms of osteogenesis imperfecta, designated type I through type VIII. The types can be distinguished by their signs and symptoms, although their characteristic features overlap. Increasingly, genetic factors are used to define the different forms of osteogenesis imperfecta.
Type I is the mildest form of osteogenesis imperfecta.
Type II is the most severe.
Other types of this condition have signs and symptoms that fall somewhere between these two extremes.
The milder forms of osteogenesis imperfecta, including type I, are characterized by bone fractures during childhood and adolescence that often result from minor trauma. Fractures occur less frequently in adulthood. People with mild forms of the condition typically have a blue or grey tint to the part of the eye that is usually white (the sclera), and may develop hearing loss in adulthood.
Other types of osteogenesis imperfecta are more severe, causing frequent bone fractures that may begin before birth and result from little or no trauma. Additional features of these conditions can include blue sclerae, short stature, hearing loss, respiratory problems, and a disorder of tooth development called dentinogenesis imperfecta.
The most severe forms of osteogenesis imperfecta, particularly type II, can include an abnormally small, fragile rib cage and underdeveloped lungs. Infants with these abnormalities have life-threatening problems with breathing and often die shortly after birth.
Ultrasound can often detect severe cases of OI during pregnancy.
The severe form of OI Type II can be seen on ultrasound when the fetus is as young as 16 weeks. Genetic testing may be able to identify the mutation. Most infants with more severe forms of osteogenesis imperfecta (such as type II) have no history of the condition in their family. In these infants, the condition is caused by new (sporadic) mutations in the COL1A1 or COL1A2 gene.
There is no cure for this disease. However, specific therapies can reduce the pain and complications associated with OI. Bisphosphonates are drugs that have been used to treat osteoporosis.
OI Type II infants have life-threatening problems with breathing and often die shortly after birth.
Osteogenesis imperfecta is a disease that causes weak bones that break easily. It is known as brittle bone disease. Sometimes the bones break for no known reason. OI can also cause many other problems such as weak muscles, brittle teeth, and hearing loss.
Update: 9 Aug 2013: New treatment for brittle bone disease found.
A new treatment for children with brittle bone disease has been developed by the University of Sheffield and Sheffield Children's Hospital.
This is the first study to clearly demonstrate that the use of the medicine risedronate can not only reduce the risk of fracture in children with brittle bones but also have rapid action - the curves for fracture risk begin to diverge after only 6 weeks of treatment.
"The fact that this medicine can be given by mouth at home (other similar medicines are given by a drip in hospital) makes it family-friendly."
The study, funded by the Alliance for Better Bone Health, trialled children with Osteogenesis Imperfecta aged 4 - 15 years and showed that oral risedronate reduced the risk of first and recurrent clinical fractures and that the drug was generally well tolerated.
To read the published article visit www.thelancet.com/journals/lancet/article/PIIS0140-6736%2813%2961091-0/fulltext