What is osteogenesis imperfecta?

Osteogenesis imperfecta (OI), also known as brittle-bone disease, is a genetic (inherited) disorder characterized by bones that break easily without a specific cause. An estimated 20,000 to 50,000 people in the U.S. have this disease. OI can affect males and females of all races.

What causes osteogenesis imperfecta?

In most cases, the cause of OI is a genetic defect that causes imperfectly formed or an inadequate amount of bone collagen, a protein found in the connective tissue.

What are the symptoms of osteogenesis imperfecta?

The following are the most common symptoms for OI. However, each child may experience symptoms differently.

There are many different types of OI, which are defined based upon genetic defect and clinical symptoms, The most common types are listed below.

According to the Osteoporosis and Related Bone Diseases National Resource Center, part of the National Institutes of Health, the types of OI and their symptoms include:

Type I
Most common Bones fracture easily Can usually be traced through the family Near normal stature to short stature Blue sclera (the normally white area of the eye ball) in some people Dental problems (brittle teeth) in some people Hearing loss in some people Most fractures occur before puberty; occasionally women will have fractures after menopause Triangular face Tendency toward spinal curvatures
Type II
Most severe form Newborns severely affected; frequently fatal, although a few have lived to adulthood Severe bone deformity with many fractures Usually resulting from a new gene mutation Very small stature with extremely small chest and under-developed lungs
Type III
Bones fracture very easily Bone deformity Tend to be isolated family incidents Very small in stature Fractures at birth very common X-ray may reveal healing of fractures that occurred while in the uterus May have hearing loss Loose joints and poor muscle development in arms and legs Barrel-shaped rib cage Triangular face Spinal curvature Possible respiratory problems
Type IV
Between Type I and Type III in severity Can frequently be traced through the family Bones fracture easily - most before puberty Normal or near-normal colored sclera Dental problems in some people Spinal curvatures in some people Possible hearing loss
Type V
Similar to Type IV in frequency of fractures and skeletal deformity Enlarged areas of bone where fractures have occurred – or even where fractures have not Forearm movement can be restricted; dislocations can occur
Type VI
Extremely rare Moderate in severity Similar in appearance and symptoms to Type IV
Type VII
Some cases resemble Type IV and others Type II, except that infants have white sclera, small heads and round faces Short stature Short upper arm bones and thigh bones Hip deformity is common
Type VIII
Similar to Types II or III, except for white sclera Severe growth deficiency Weakened skeletal bones

The symptoms of OI may resemble other bone problems or medical conditions. Always consult your child's health care provider for a diagnosis.

How is osteogenesis imperfecta diagnosed?

Because this is a genetic disorder, your child's doctor will take a careful family history in addition to a complete medical history and do a physical examination. In most cases, the genetic defect is identified with a blood test. In some cases a skin biopsy may be necessary, and sometimes no genetic defect can be found.

Additional diagnostic tests include:

• X-ray. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

• DXA scan. A diagnostic procedure to determine bone mineral density.

• Audiometry. This is a hearing test using electronic tones. 

Treatment for osteogenesis imperfecta

Specific treatment for OI will be determined by the severity of your child's disease. 

To date, no known treatment, medicine, or surgery will cure OI. The goal of treatment is to prevent deformities and fractures and allow the child to function as independently as possible. Treatments for preventing or correcting symptoms may include the following:

• All patients will receive nutritional counseling to ensure they are getting enough calcium and vitamin D in their diet

• In most cases, patients will receive physical therapy to improve muscle strength and bone density

• All patients will see an orthopaedic surgeon to care for fractures

• Some patients with severe disease will have rods inserted into long bones to strengthen and prevent deformity

• Some patients will need surgery to repair scoliosis (spinal curvature)

• Medical treatment with bisphosphonates are the standard of care for patients with moderate or severe disease

• Dental procedures

• Assistive devices such as wheelchairs, braces,and other custom-made equipment

Management of osteogenesis imperfecta

Management of the disease includes focusing on preventing or minimizing deformities and maximizing the child's functional ability at home and in the community. Management of OI is either nonsurgical or surgical. Nonsurgical interventions may include one or more of the following:

• Regular exercise and a healthy diet. These are recommended for proper weight maintenance.

• Positioning aids. These are used to help the child sit, lie, or stand.

• Braces and splints. These are used to prevent deformity and promote support or protection.

• Medications

• Avoidance of smoking

• Psychological counseling

Surgical interventions may be considered to manage the following conditions:

• Fractures

• Bowing of bone

• Scoliosis, a condition that causes the back bones to curve

Long-term outlook for a child with osteogenesis imperfecta

OI is a progressive condition that needs life-long management to prevent deformity and complications.

The interdisciplinary health care team helps the family to improve the child's functional outcomes and to provide support to the parents as they learn to care for their child's needs.

The Osteogenesis Imperfecta Society can be an important resource for parents of children with OI.

Online Medical Reviewers:

• Bass, Pat F. III, MD, MPH
• David Weber, MD, MSCE
• MMI board-certified, academically affiliated clinician
• MMI board-certified, academically affiliated clinician,