Osteogenesis imperfecta (brittle bone disease) is a genetic disease that makes your bones thin and brittle. People with osteogenesis imperfecta break bones easily, with little or no force causing the break. It can also cause a curved spine, muscle weakness, difficulty breathing and other issues. The most common type causes mild symptoms.
Osteogenesis imperfecta (OI), also known as brittle bone disease, is a connective tissue disease that makes your bones fragile and easily broken, with little or no force. It causes your body to make less type I collagen than it needs, or to make improperly formed collagen. The name osteogenesis imperfecta means “imperfectly formed bone.”
Collagen is a protein that plays an important role in the structure and development of your bones, skin, muscles and tendons. This means people with brittle bone disease not only have many bone fractures in their lives; they can also have issues with their teeth, skin, spine, lungs and other parts of their bodies.
While the most common form of osteogenesis imperfecta usually causes mild symptoms, some forms can cause severe disabilities.
Healthcare providers classify osteogenesis imperfecta into 19 types (type I through type XIX), depending on collagen formation and its effects on your body. Types I through IV are the most common.
People with type I (1) osteogenesis imperfecta have lower amounts of normal collagen than people without OI. People with types II (2), III (3) and IV (4) have improperly formed collagen and more severe symptoms.
This is the most common form of OI. It causes milder symptoms than other types. People with type I osteogenesis imperfecta get broken bones more easily than people without it, but most broken bones happen before puberty. It doesn’t cause bone deformity. It’s also called classic non-deforming osteogenesis imperfecta with blue sclerae.
Type II is the most serious form of osteogenesis imperfecta. It causes severe complications, like underdeveloped lungs (due to poor rib cage development), serious bone deformities and multiple broken bones before birth. Babies with type II osteogenesis imperfecta die at or shortly after birth. It’s also known as perinatally lethal osteogenesis imperfecta.
Type III osteogenesis imperfecta is the most severe form of OI that you can survive past birth. It causes severe bone deformities, making bones very fragile and easily breakable, and leading to physical disabilities. Babies often have broken bones at birth. It’s also called progressively deforming osteogenesis imperfecta.
Type IV is more severe than type I but less severe than type III. People with Type IV have mild to moderate bone deformities, causing bones that are more fragile than people without OI, but not as easily broken as with type III OI. It’s also called common variable osteogenesis imperfecta with normal sclerae.
Osteogenesis imperfecta is rare. It affects around 1 in every 20,000 people worldwide.
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Signs and symptoms of osteogenesis imperfecta can include:
A genetic variation (mutation) causes osteogenesis imperfecta (brittle bone disease). Mutations in the COL1A1 or COL1A2 genes cause most cases. These two genes make type I collagen, which helps keep bones strong. A change in one of these two genes causes your body to either make less collagen than it needs or to make improperly formed collagen. More rare forms are caused by changes in other collagen genes.
Changes that cause OI may be sporadic (random) or you might inherit the gene from one or both biological parents. Some people are carriers for the gene variation that causes OI — and can pass it on to their children — but don’t have it themselves.
The four most common types of osteogenesis imperfecta are inherited in an autosomal dominant pattern. Other types are inherited in an autosomal recessive or X-linked pattern.
Anyone can be born with brittle bone disease. But you’re more likely to have OI if someone else in your biological family has it.
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Complications of osteogenesis imperfecta depend on the type and severity. They include:
Providers usually diagnose brittle bone disease in childhood with:
A pregnancy care provider might suspect osteogenesis imperfecta before birth based on ultrasound images. They can confirm the diagnosis during pregnancy with an amniocentesis (with genetic testing on the cells) or after the baby is born.
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Treatment for osteogenesis imperfecta can increase bone strength and help people with OI live more independently. Treatment may include:
Because brittle bone disease is a genetic condition, you can’t prevent it. If you or your partner has OI or if you have a relative with the condition, you can talk to a genetic counselor. They can advise you about the risks of passing on the condition.
Life expectancy for someone with the most common (and mildest) form of osteogenesis imperfecta can be the same as someone without it. But life expectancy varies greatly depending on the type. For instance:
If you or your child has osteogenesis imperfecta, you can help keep bones healthy by:
If you notice you or your child gets broken bones easily — especially without significant injury — or has other symptoms of OI, talk to a healthcare provider. They can recommend additional testing if needed.
Go to the nearest emergency room if you or your child breaks a bone. Let them know if you have osteogenesis imperfecta.
It might be helpful to ask your healthcare provider:
Yes, people with mild forms of osteogenesis imperfecta can walk. Some people may use braces or crutches. Early treatments like physical and occupational therapy can help increase the chances that your child will be able to walk.
A note from Cleveland Clinic
Learning that your child has a condition that’ll affect them their whole life can feel overwhelming. The future might look much different than you expected. But early occupational and physical therapy can help both you and your child adapt to these changes. It can also help to have honest conversations with your child’s healthcare team and your loved ones every step of the way. They can help you make a plan to manage symptoms and prepare for the future.
Last reviewed on 08/18/2024.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy