• OI History
• OI Symptoms
• OI Genetics
• OI Characteristics

Almost all individuals with Osteogenesis Imperfecta have fragile bones that break easily.

Osteogenesis Imperfecta (OI) literally means "imperfectly formed bone." People with Osteogenesis Imperfecta have an error (mutation) in the genetic instructions on how to make strong bones. This may cause the bones to break easily.

Osteogenesis Imperfecta (OI) is a generalized abnormality of bones due to problems with Type I collagen formation. There are at least 4 recognized types, although differentiation between types can be difficult in the newborn period.

The types can be distinguished by their signs and symptoms, although their characteristic features overlap.


The major symptoms of each of the four types are:

• Type I - whites of the eyes (sclera) are blue; bone fractures more common during infancy and decrease after puberty; easy bruising; hearing loss.
  
  
• Type II - bone fractures are present before birth; small nose and lower jaw; hearing not affected.
  
  
• Type III - 50% of individuals have bone fractures before birth; the rest have bone fractures shortly after birth; shortening of limbs and progressive deformities; facial abnormality; hearing not affected.
  
  
• Type IV - Bone fractures begin in infancy; hearing not affected.
  

OI can affect a person so mildly that they can spend years and years with this disease and not even realize that they even have it. Other individuals can be so severely affected by it that it is very present before birth by means of an ultra-sound or is visible at the time of birth by x-ray.

Patients often have a family history of OI, but most cases are due to new mutations. Patients most commonly present with fractures after minor trauma.

In severe cases, prenatal screening sonography performed during second trimester may show bowing of long bones, fractures, limb shortening, and decreased skull echogenicity. Lethal OI cannot be diagnosed with certainty in utero. Patients may bruise easily. Patients may have repeated fractures after mild trauma. However, these fractures heal readily. Deafness is another feature. About 50% of type I OI have deafness by the age of 40 years.

Physical examination can vary depending on the severity. Degrees of severity may vary among different affected members of the same family.