What is osteogenesis imperfecta?
Osteogenesis imperfecta (OI) is a genetic bone disorder in which bones are fragile and break more easily. It has also been called “brittle bone disease”. It is a rare condition that affects 1 in 20,000 births. There are 16 different types that vary from mild to severe.
What causes osteogenesis imperfecta?
OI is caused by changes in genes that affect bone strength. These changes, or mutations, can occur spontaneously or can be inherited from a parent. A person with OI usually has a 50% chance of passing it on to their child. The gene that is most often affected is the collagen gene. Collagen is a protein that provides structure to many parts of the body. The type of collagen affected in OI is type 1, which helps to strengthen skin and bone.
What are the signs and symptoms of osteogenesis imperfecta?
Children with OI may experience bone-related issues, such as broken bones, scoliosis, and skull deformities. They may also be shorter than average height for their family. Other associated signs and symptoms include blue/gray tint to the whites of the eyes, hearing loss, dental issues, looseness of skin or joints, and easy bruising as collagen contributes to the structure of the skin and other parts of the body.
Of the 16 types of OI, type 1 is the mildest form and type 2 is the most severe. Type 1 OI is the most common form and individuals with this condition tend to have some broken bones although not as many as other types, muscle weakness, blue/gray tint to the whites of the eyes, and hearing loss. There is a wide range of signs and symptoms depending on the type of OI. Your endocrine health care provider can help to explain what the effects of your type of OI might be, if it is known what type you have.
How is osteogenesis imperfecta diagnosed?
OI is diagnosed in individuals who have the signs and symptoms discussed above. Knowing the family history of similar signs and symptoms can also be helpful and lead to a diagnosis. Genetic testing can help check for some of the more common causes of OI, but may miss other types. If OI is suspected prenatally, there are ways to look for skeletal issues with ultrasound and other imaging techniques before birth.
How is osteogenesis imperfecta treated?
Treatment may include physical therapy, occupational therapy, medical therapy and bone surgery. Bone surgery may focus on fixing fractures, treating scoliosis, and/or placing rods to help correct bone deformities. Bisphosphonates are medications that can help strengthen bone and prevent fractures. Oral or intravenous forms of these medications may be recommended.
Treatment decisions are made on an individual basis with your medical team. It is important to have close follow up with your team of doctors. The team may include an endocrinologist, orthopedic surgeon, general pediatrician, and/or physical therapist. You should contact your team if your child continues to have symptoms or with any further questions.
Pediatric Endocrine Society
Section on Endocrinology Patient Education Committee