Osteogenesis Imperfecta (OI)

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 because of a genetic defect that causes imperfectly formed or an inadequate amount of bone collagen, a protein 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. Although symptoms may vary, generally there are eight forms of OI, each of which represents varying levels of severity.

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
• Mildest form
• Bones fracture easily
• Can usually be traced through the family
• Near normal stature or slightly shorter
• Blue sclera (the normally white area of the eye ball)
• Dental problems (brittle teeth)
• Hearing loss beginning in the early 20s and 30s
• 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
• Problems with teeth
• Spinal curvatures
• 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

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 exam. Additional tests include and ear, nose and throat exam to detect hearing loss.

How is osteogenesis imperfecta treated?

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:

• Care of fractures
• Surgery
• Rodding, a procedure to insert a metal bar the length of a long bone to stabilize it and prevent deformity
• Dental procedures
• Physical therapy
• Assistive devices, such as wheelchairs, braces and other custom-made equipment

How is osteogenesis imperfecta managed?

Management of the disease includes 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
• Avoidance of steroid medications
• 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
• Heart problems

Surgery may also be considered to maintain a child’s ability to sit or stand.

What is the long-term outlook for a child with osteogenesis imperfecta?

OI is a progressive condition that needs lifelong management to prevent deformity and complications. Our interdisciplinary team helps the family improve the child’s quality of life and to provide support to the parents as they learn to care for their child’s needs.