What are the symptoms of osteogenesis imperfecta (OI)?

All types of OI have some degree of bone fragility and fracturing, and many have some degree of bone deformity.

The symptoms of OI vary by type:

• Type I
  • Most common and mildest form of OI. It can be so mild that healthcare providers do not diagnose it in some people until they are adults.
  • Bone fractures occur mostly in years before puberty and decrease in frequency after puberty.
  • Normal height; a few inches shorter than same gender relatives
  • Little or no bone deformity
  • Brittle teeth in rare cases
  • Hearing loss in some cases
  • Blue sclera (whites of the eyes)
  • Easy bruising
  • Mild delay in motor skills
• Type II
  • Severe; usually results in stillborn birth or death in the first months of life
  • Severe bone deformity
• Type III
  • Most severe, nonlethal form
  • Hundreds of fractures starting very early in life
  • Severe bone deformities and physical disability that worsen over time
  • Sclera may be blue or grey
  • Triangular face and prominent forehead
  • Scoliosis (abnormal curving of the spine)
  • Sunken or protruding chest wall
  • Brittle teeth
  • Hearing loss
  • Very short height
  • Motor skill delays
  • Usually need wheelchairs
• Type IV
  • Similar to type I but with mild to moderate bone deformity
  • Dozens of fractures on average, most of which occur before puberty or after middle age
  • Motor skill delays
  • People with type IV often need braces or crutches to walk
  • Short height
  • Brittle teeth
  • Hearing loss in some cases
  • White or blue sclera
  • Scoliosis
  • Large head
  • Easy bruising
• Type V
  • Identical symptoms to Type IV except:
    • Normal sclera
    • Normal teeth
    • Severely limited ability to twist forearms clockwise or counterclockwise
  • Distinguished from Type IV by differing bone features at microscopic level
• Type VI
  • Identical symptoms to Type IV except:
  • • Normal teeth
    • Greater frequency of fractures
  • Distinguished from Type IV by differing bone features at microscopic level
• Type VII and VIII
  • Similar to Types II and III
  • Severe or lethal bone deformity
  • Type VII can also involve small head, blue sclera, bulging eyes
  • Some people with Type VIII have lived into their second or third decade
• Type IX
  • Moderate to severe bone deformity and similar to Types III and IV
  • White sclera
  • Short height
• Type X
  • Severe and often leads to death.
• Type XI
  • Bone deformities worsen over time

The bone deformities and collagen defects common to OI can affect various internal organs, leading to secondary problems. These include:

Lung Problems

People with OI are more vulnerable to lung problems, including asthma and pneumonia. Viral and bacterial infections can become severe. In fact, respiratory failure is the most common cause of death in people with OI.

Lung problems result from a combination of factors. If the ribs and spine do not develop normally, there may be less space for the lungs to expand. Collagen also is an important building block of connective tissue in the lungs. If the body does not make enough collagen, or makes abnormal collagen, the lungs do not work properly. This makes it difficult for people with OI to get enough oxygen through their bodies. In addition, they may have problems coughing effectively to clear away mucus.¹

Heart Problems

Heart problems, such as incorrectly working valves and arteries, sometimes occur in people with OI.

Neurological Problems

People with OI often have enlarged heads, called macrocephaly. They can also have a condition called hydrocephalus, in which fluid builds up inside the skull, causing the brain to swell.

People with severe OI often have basilar invagination, a malformation of the spinal column that puts pressure on the spinal cord and brain stem. It worsens over time and can cause severe headaches, changes in facial sensation, lack of control over muscle movements, and difficulty swallowing. If untreated, basilar invagination can lead to rapid neurological decline and inability to breathe.^2,3,4