Osteogenesis Imperfecta (Brittle Bone Disease)

What is osteogenesis imperfecta?

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.

Types of osteogenesis imperfecta

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.

Type I

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

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

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

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.

How common is osteogenesis imperfecta?

Osteogenesis imperfecta is rare. It affects around 1 in every 20,000 people worldwide.

What are the symptoms of osteogenesis imperfecta (brittle bone disease)?

Signs and symptoms of osteogenesis imperfecta can include:

• Brittle bones that break easily.
• Bone deformities.
• Bone pain.
• Blue or gray sclerae (the whites of your eyes).
• Bruising easily.
• Difficulty breathing.
• Hearing loss.
• Loose joints.
• Muscle weakness.
• Curved spine (kyphosis or scoliosis).
• Small stature.
• Triangular face shape.
• Weak, brittle or discolored teeth.
• Teeth that don’t align properly (malocclusion).
• Barrel-shaped rib cage.

What causes osteogenesis imperfecta?

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.

What are the risk factors for osteogenesis imperfecta?

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.

What are the complications of osteogenesis imperfecta?

Complications of osteogenesis imperfecta depend on the type and severity. They include:

• Heart disease, including heart failure.
• Frequent pneumonia.
• Respiratory issues, including respiratory failure.
• Issues that affect your nervous system.

How is osteogenesis imperfecta diagnosed?

Providers usually diagnose brittle bone disease in childhood with:

• Genetic testing.
• Bone density tests.

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.

How is osteogenesis treated?

Treatment for osteogenesis imperfecta can increase bone strength and help people with OI live more independently. Treatment may include:

• Occupational therapy (OT). OT can help you with skills to manage daily activities.
• Physical therapy (PT). Physical therapy can help you strengthen your bones and muscles with low-impact exercises.
• Assistive devices. Aids like walkers, canes or crutches can improve mobility.
• Oral and dental care. Regular dental checkups can help monitor and address tooth and jaw issues. You may need orthodontic care to correct certain issues.
• Pulmonary care. You may see a pulmonologist (a doctor who specializes in lung conditions) to help with breathing issues.
• Medications. Your provider may prescribe bisphosphonates to help strengthen bones.
• Surgery. A surgeon may place metal rods to correct curved or misshapen bones. The rods also help support your bones.
• Braces, splints or casts. Protective devices stabilize broken bones during healing or after surgery.

Can osteogenesis imperfecta be prevented?

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.

What is the life expectancy of a person with osteogenesis imperfecta?

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:

• People with type I usually live a typical lifespan.
• People with type IV generally live into adulthood but may have a slightly shortened lifespan.
• Babies with type II die at or shortly after birth.

How can I improve bone health with osteogenesis imperfecta (OI)?

If you or your child has osteogenesis imperfecta, you can help keep bones healthy by:

• Eating foods high in calcium and vitamin D.
• Participating in physical activities as recommended by your healthcare provider.
• Limiting alcohol and caffeine intake.
• Quitting smoking and avoiding secondhand smoke.
• Taking care of your mental health. Especially for children and teens, it might be helpful to talk to a social worker or counselor about mental health issues that can come with chronic illnesses.

When should I see my healthcare provider?

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.

When should I go to the ER?

Go to the nearest emergency room if you or your child breaks a bone. Let them know if you have osteogenesis imperfecta.

What questions should I ask my healthcare provider?

It might be helpful to ask your healthcare provider:

• What type of osteogenesis imperfecta do I/does my child have?
• What should I know about the life expectancy with OI?
• How can I manage (or help my child manage) OI symptoms?
• What should I do if I/my child breaks a bone?
• What are the chances that I’ll have another child with osteogenesis imperfecta?

Can someone with osteogenesis imperfecta walk?

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.