Osteogenesis Imperfecta (Brittle Bone Disease)

Osteogenesis imperfecta (OI) makes your bones much weaker and more fragile than usual. That’s why it’s also known as brittle bone disease. It’s a genetic condition you’re born with.

Osteogenesis imperfecta means “imperfectly formed bone.” If you have OI, your body makes much less collagen than it should. Or the collagen you have doesn’t form correctly. This weakens your bones and makes them more brittle than usual. The missing or incorrect collagen can also affect your:

• Teeth
• Skin
• Spine
• Lungs
• Other internal organs

It typically takes an injury like a serious fall to break bones. Having OI makes you much more likely to break bones throughout your life. And if you have OI, your bones may break with little or no force.

The most common form of OI usually causes only mild symptoms. But some types can cause severe symptoms, lead to disabilities or be fatal.

Types of osteogenesis imperfecta

There are 19 types of osteogenesis imperfecta. Types I, II, III and IV are the most common OI types:

• Type I: This is the most common type of OI. It causes milder symptoms than other OI types. You’ll break bones more easily than usual. But most broken bones happen before puberty. It doesn’t typically cause misshapen bones (bone deformity).
• Type II: This is the most serious OI type. Babies with type II die at or shortly after birth. It causes fatal complications like underdeveloped lungs, serious bone deformities and multiple broken bones before birth.
• Type III: Type III is the second most severe form. It causes dangerous bone deformities. This makes your bones very fragile. You’ll live with physical disabilities. Babies with type III are often born with broken bones.
• Type IV: Type IV is more severe than type I. But it’s less severe than type III. Your bones will be more fragile than usual. But they won’t break as often as with type III.

Type I causes lower-than-usual amounts of collagen. Types II, III and IV cause improperly formed collagen.

Symptoms of osteogenesis imperfecta

Osteogenesis imperfecta can cause lots of symptoms, depending on which type you have. You may have bone symptoms, including:

• Weak, thin bones that break easily
• Bone deformities
• Bone pain
• Loose joints
• A curved spine
• A barrel-shaped ribcage
• Small stature

OI can also cause symptoms in other parts of your body, including:

• The whites in your eyes looking blue or gray
• Bruising easily
• Trouble breathing
• Hearing loss
• Muscle weakness
• Triangular face shape
• Weak, brittle or discolored teeth
• Teeth that don’t align properly

Osteogenesis imperfecta causes

A genetic change causes brittle bone disease. Changes in the COL1A1 or COL1A2 genes cause most cases. These two genes make type I collagen, which helps keep your bones strong. A change in these genes causes your body to make either less collagen than it needs or to make improperly formed collagen. Rarer forms are caused by changes in other collagen genes.

The genetic changes that cause OI can pass through biological families. Some people are carriers for the genetic changes that cause it, but don’t have it themselves. Talk to a healthcare provider if you’re worried about passing any genetic conditions to your biological children.

Complications of brittle bone disease

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

Some types can cause fatal complications, especially type II.

How doctors diagnose brittle bone disease

A healthcare provider will diagnose brittle bone disease in childhood with genetic testing and X-rays, as well as discussing your biological family health history.

A pregnancy care provider may diagnose osteogenesis imperfecta while a fetus develops. They might be able to see unusual bone development on ultrasounds. They can confirm OI with amniocentesis.

Osteogenesis imperfecta treatments

Your healthcare provider will suggest treatments to increase your bone strength and avoid fractures. You may need:

• Occupational therapy
• Physical therapy
• Assistive devices, like walkers, crutches or a cane
• Medications or supplements to strengthen your bones
• Oral or dental treatments, if OI affects your teeth
• Surgery to insert extra support into curved or fragile bones
• Other treatments for lung, spine or skin issues

You’ll need specific treatments if you break a bone. Your healthcare provider will tell you what to expect.

When should I see my healthcare provider?

Go to the emergency room if you think you have a broken bone. Don’t try to use that part of your body. Tell providers in the ER if you know you have osteogenesis imperfecta.

Your provider will let you know how often you’ll need follow-up exams and tests. They’ll monitor your bone density and look for signs of complications.

What can I expect if I have brittle bone disease?

You should expect to manage brittle bone disease for the rest of your life. Your healthcare provider will help you find the right treatments. They’ll work with you so you know how to manage symptoms and reduce your risk of bone fractures. Eventually, your bone density may go up, but there’s no cure for osteogenesis imperfecta.

You might have to avoid certain intense physical activities or contact sports. But having OI doesn’t mean you can’t exercise or have hobbies. Your provider will tell you which kinds of activities may increase your risk of a broken bone.