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.
The cause of OI is believed to be due to a genetic defect that causes imperfectly-formed, or an inadequate amount of, bone collagen--a protein found in the connective tissue.
Previously, there were considered to be four types of OI. Research has now shown that there are eight specific types of the disease. Types 2, 3, 7, and 8 are the most severe types. Type 1 OI is the mildest. And types 4, 5, and 6 are moderate in severity.
Symptoms of OI include:
Easily fractured bones
Bone deformities, such as bowing of the legs, due to multiple fractures and poor fracture healing
Discoloration of the sclera of the eye. This normally white tissue may be blue or gray in people with OI.
A barrel-shaped chest
A curved spine
A triangular-shaped face
Hearing loss in early adulthood
The symptoms of osteogenesis imperfecta may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.
In addition to a complete medical history and physical examination, diagnostic procedures for osteogenesis imperfecta may include a skin biopsy to evaluate the amount and structure of collagen. However, this test is complicated and not many qualified facilities are available to perform the procedure. It is not unusual for results of the biopsy to take up to six months.
Additional diagnostic tests may include:
X-ray. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
An examination of the ear, nose, and throat (to detect hearing loss)
Specific treatment for osteogenesis imperfecta will be determined by your doctor based on:
Your age, overall health, and medical history
Extent of the disease
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
To date, there is no known treatment, medicine, or surgery that 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:
Care of fractures
Rodding. A procedure to insert a metal bar the length of a long bone to stabilize it and prevent deformity.
Assistive devices, such as wheelchairs, braces, and other custom-made equipment
Management of the disease includes focusing on preventing or minimizing deformities, and maximizing the individual'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:
Positioning aids to help sit, lie, or stand
Braces and splints to prevent deformity and provide support or protection
Surgical interventions may be considered to manage the following conditions:
Bowing of bone
Scoliosis. A lateral, or sideways curvature and rotation of the back bones (vertebrae), giving the appearance that the person is leaning to one side.
Surgery may also be considered to maintain the ability to sit or stand.
OI is a progressive condition that needs lifelong management to prevent deformity and complications. The interdisciplinary health care team helps the family to improve the functional outcomes and to provide support. The Osteogenesis Imperfecta Foundation can also be an important resource.