Information About Osteogenesis Imperfecta

Inherited collagen disorder

X-ray of broken arm bones
X-ray of broken arm bones. Photo © A.D.A.M.

Osteogenesis imperfecta, an inherited condition also known as brittle bone disease, results from an abnormality in connective tissue called type I collagen. Type I collagen fibers are found in bones, tendons, the skin, and in the eyes. Osteogenesis imperfecta usually begins either in utero or in infancy, is classified into four types, and occurs in one per 30,000 to 70,000 live births, depending on the type.


Almost all individuals with osteogenesis imperfecta have fragile bones that break (fracture) easily. The major symptoms of each of the four types are:
  • Type I - the mildest and most common form of OI (about 50% of individuals) - whites of the eyes (sclera) are blue; bone fractures more common during infancy and decrease after puberty; easy bruising; high incidence of hearing loss.
  • Type II - the most severe form - bone fractures are present before birth, often in the skull, long bones, or vertebrae; whites of the eyes are dark blue or gray; bones are malformed; lungs are underdeveloped. Babies born with Type II often die within weeks of birth due to heart and breathing problems.
  • Type III - 50% of individuals have bone fractures before birth; the rest have bone fractures shortly after birth; shortening of limbs and deformities; facial abnormality; children and adults have short stature.
  • Type IV - Bone fractures begin in infancy; children have difficulty growing.
Research has identified a Type V and Type VI that are not due to problems with type I collagen. Types VII and VIII were identified in 2006. These two types are inherited in a different way than the other types.


Diagnosis of osteogenesis imperfecta is based on the discovery of a number of fractures in the infant's or child's arms, ribs, and legs.
X-rays can uncover fractures that might not be obvious. Child abuse can also produce broken bones, but the ways the bones break and which bones are typically broken is usually different than in osteogenesis imperfecta. Some children with milder forms of OI might not be diagnosed until they are older. Specific genetic testing is available for some forms of OI.


There is no cure for osteogenesis imperfecta, so treatment focuses on reducing the number and frequency of fractures. Parents need to learn how to handle, position, and hold the child with osteogenesis imperfecta in ways that have the least possibility of causing fractures. Supportive shoes with arch supports are important, and leg braces may be helpful for the child learning to walk. Physical therapy can help keep joints mobile and strengthen muscles. In some cases bone surgery may be attempted, but this is difficult to accomplish because the bones are fragile. Research is being done to develop drugs to strengthen the bones.

Genetic counseling

Parents of a child with osteogenesis imperfecta should receive genetic counseling if they wish to have more children.
Types I through VI of the disorder are inherited in an autosomal dominant pattern, meaning only one defective gene needs to be inherited for osteogenesis imperfecta to appear. Therefore, each future child has a 50% chance of being born with the disorder.

Types VII and VIII are inherited in an autosomal recessive pattern. This means the child needs to inherit two defective genes, one from each parent, in order to have the disorder.


"Facts about Osteogenesis Imperfecta." About OI. Osteogenesis Imperfecta Foundation. 18 Nov 2008

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