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Doctors at Hassenfeld Children’s Hospital at ºÙºÙÊÓƵ are experienced in diagnosing children and adolescents who have osteogenesis imperfecta, a rare genetic condition that weakens bones and causes them to break easily. Most people who have osteogenesis imperfecta have a mutation, or change, in one of two genes—COL1A1 or COL1A2. These genes produce collagen, an important protein found in bone. Changes in the genes CRTAP or LEPRE1 that produce cartilage, a flexible connective tissue found throughout the body, can also cause osteogenesis imperfecta.

This condition often runs in families. However, about one-third of children with osteogenesis imperfecta have no close relatives with the condition.

Several types of osteogenesis imperfecta have been identified, with symptoms ranging from mild to severe. Most children have the mild-to-moderate form.

Signs and Symptoms

Frequent bone fractures are the most common sign of osteogenesis imperfecta. Children with this condition may also have more laxity, or looseness, in their ligaments.

Children with milder forms of osteogenesis imperfecta may have thinning of the whites of the eyes, which gives them a blue or gray appearance. They may also develop tooth discoloration or erosion of tooth enamel.

Children with moderate-to-severe forms of osteogenesis imperfecta may develop conditions that cause abnormal curvature of the spine—such as scoliosis or excessive kyphosis—because of repeated, tiny fractures in the bones of the spine. Bowing of the legs may occur when the growth plates—the areas of soft cartilage near the ends of each bone—in the legs do not function properly.

Children with moderate-to-severe osteogenesis imperfecta may also develop hearing loss, which is caused by problems with the bones outside the ear or in the middle ear that help to transmit sound waves to the brain.

The risk of new bone fractures usually subsides during adolescence, after a child is finished growing.

Obtaining an Accurate Diagnosis

In the most severe type of osteogenesis imperfecta, a baby’s bones may be fractured before or during birth. Babies with milder forms of osteogenesis imperfecta are more likely to be diagnosed early if they have unusual fractures before they begin walking. In other instances, the diagnosis may occur when the child becomes more active. Delayed diagnosis or misdiagnosis of osteogenesis imperfecta is common in children and adolescents who are physically active and play sports, because their fractures are often attributed to their level of activity rather than to an underlying medical condition.

Accurate diagnosis and an appropriate care plan can help to protect children from fractures and other complications of osteogenesis imperfecta throughout childhood and into adulthood. Doctors at Hassenfeld Children's Hospital may perform the following tests to determine if osteogenesis imperfecta may be the cause of a child’s bone fractures:

Physical Exam

During a physical exam, the doctor asks about your child’s medical history, including any fractures or dental problems caused by tooth erosion. He or she also looks for common physical signs of osteogenesis imperfecta in children, such as a bluish tint in the whites of the eyes, loose joints, and tooth discoloration.

If you or your child has noticed any hearing problems, the doctor may refer you to one of our pediatricians, who can perform a comprehensive hearing test.

Skin Biopsy

In a skin biopsy, a local anesthetic is applied to a small area of your child’s skin. The doctor removes a small skin sample and sends it to a laboratory for microscopic evaluation. A clinical geneticist can then discuss the test results with your family. Children with osteogenesis imperfecta, for instance, may be found to have low collagen levels.

Blood Tests

A blood test may be performed to identify specific genetic mutations associated with osteogenesis imperfecta. Another blood test may also be used to rule out low levels of vitamin D as the cause of your child’s fractures.

X-rays

An X-ray may be used to look at your child’s bone structure for signs of past fractures and to assess the alignment of the bones. Additional imaging tests that use X-rays to measure bone mineral density may be needed to determine the strength of your child’s bones.

Accurately diagnosing osteogenesis imperfecta enables our doctors to provide parents and children with treatments and strategies to prevent additional fractures.