Inherited Brittle Bones (Osteogenesis Imperfecta)

________________________________________________________________________

KEY POINTS

• Osteogenesis imperfecta (OI) is a rare inherited disease that causes weak bones. The severity of symptoms depends on the type of OI your child has.
• Treatment can help manage the symptoms, prevent problems and injuries, and keep the bones and muscles as strong as possible. Your child may need medicine, exercise, or surgery.
• Ask your child’s healthcare provider how to take care of your child at home, what symptoms or problems you should watch for, and what to do if your child has them.

________________________________________________________________________

What is osteogenesis imperfecta?

Osteogenesis imperfecta (OI) is a rare inherited disease that causes weak bones. There are several types of OI. The severity of symptoms depends on the type of OI your child has. Some types of OI may start before a child is born and may cause the baby to die before birth. Other types may not be diagnosed until late childhood or the teenage years. A child with OI may need braces or crutches to walk. Or the child may be unable to walk and use a wheelchair.

OI can cause broken and deformed bones. Broken bones will heal, but in the process of healing, they may be deformed.

What is the cause?

OI is caused by a problem with the genes that make collagen. Genes are inside each cell of the body. They contain the information that tells the body how to develop and work. Collagen is needed for strong bones and other tissues. If your child’s collagen is not normal or there is not enough of it, bones will be weak and break easily.

Abnormal genes that cause OI can be passed from parent to a child. Some children with OI are born to families with no history of the disease. Because there are different genes that cause OI, the disease can be very different from one person to another, ranging from very mild to severe.

What are the symptoms?

The symptoms of this disease vary greatly, even among people with the same type of the disease. Symptoms may include:

• Bones that break very easily, often from little or no cause, which is the most common symptom
• Whites of the eyes that are blue or have a purple or gray shade
• Early hearing loss
• Shorter height than normal
• Teeth that are dark colored or break easily
• Curving of the spine (scoliosis)
• Weak muscles and less ability to exercise
• Easy bruising
• Problems with breathing
• Constipation
• Loose joints
• Thin, smooth skin
• High-pitched voice

Most broken bones start happening in infancy or early childhood. Broken bones happen less often as a child goes through puberty. Women with OI have more broken bones after menopause. Men may start to break more bones after age 60.

How is it diagnosed?

Sometimes a mild case of OI may not be noticed until a bone breaks. Your healthcare provider will ask about your child’s medical and family history and examine your child. Tests may include:

• Blood tests to check the genes
• Skin biopsy to test the collagen. A biopsy is removal of a small piece of skin for lab tests.

Although these are the best tests for OI, sometimes the test results may be negative even though your child has OI.

How is it treated?

Your child’s healthcare provider will refer your child to a specialist for treatment, such as an orthopedist who is a doctor that specializes in bone problems, or an endocrinologist who is a doctor that specializes in hormone problems. Your child may also need to see other specialists such as a physical therapist or an ear, nose, and throat specialist.

The goals of treatment are to manage the symptoms, prevent problems and injuries, and keep the bones and muscles as strong as possible. There is no cure yet for OI.

Treatment includes:

• Medicine: Medicine is used to help reduce pain, strengthen bone, and reduce the number of broken bones. The medicine may be given every few months by vein (IV).
• Exercise: As your child gets older, exercise should become part of your child’s daily routine. For children with milder forms of OI, walking and swimming are usually good ways to keep up muscle strength. Be sure to follow the exercise program recommended by your child’s healthcare provider and physical therapist.

Sometimes surgery may be done. For example, rods may be put into long bones in arms or legs to support the bones.

Be aware of the public concern about possible abuse when you take a child with a broken bone to a new healthcare provider or the hospital. You may want to ask your child's healthcare provider to give you a letter to carry with you that explains your child's condition.

How can I take care of my child?

• Follow your child’s healthcare provider’s instructions for treatment.
• Teach your child how to try to avoid bone injuries. This will take the support of many people including parents, siblings, friends, teachers, principals, and many others. You may want to ask a child psychologist about how to encourage your child to do safe activities. Children with any type of OI should not play contact sports.
• Teach your older child not to smoke.
• Ask your child’s provider:
  • How and when you will get your child’s test results
  • If there are activities your child should avoid and when your child can return to normal activities
  • How to take care of your child at home
  • What symptoms or problems you should watch for and what to do if your child has them
• Make sure you know when you should bring your child back for checkups.

How can this disease be prevented?

If you have OI, or there is OI in your family, it’s a good idea to talk with a genetic counselor before you decide to have children.

You can get more information from:

• OI Foundation
  800-981-2663
  http://www.oif.org