What are the types of Osteogenesis Imperfecta?

By  ,  National Institute of Health
Jan 06, 2013

Type I OI

  • most common and mildest type of OI
  • bones predisposed to fracture (most fractures occur before puberty)
  • normal or near-normal stature
  • loose joints and muscle weakness
  • blue, purple, or gray tint to sclera (whites of the eyes)
  • triangular face
  • tendency toward spinal curvature
  • absent or minimal bone deformity
  • possible brittle teeth
  • possible hearing loss, often beginning in early twenties or thirties
  • normal collagen structure, but less than normal amount

Type II OI

  • most severe form of OI
  • frequently causes death at birth or shortly after, because of respiratory problems
  • numerous fractures and severe bone deformity
  • small stature with underdeveloped lungs
  • blue, purple, or gray tinted sclera
  • improperly formed collagen

Type III OI

  • easily fractured bones (Fractures often present at birth, and x rays may reveal healed fractures that occurred before birth.)
  • small stature
  • blue, purple, or gray tinted sclera
  • loose joints and poor muscle development in arms and legs
  • barrel-shaped rib cage
  • triangular face
  • spinal curvature
  • possible respiratory problems
  • often severe bone deformity
  • possible brittle teeth
  • possible hearing loss
  • improperly formed collagen

Type IV OI

  • between Type I and Type III OI in severity
  • bones easily fractured (most fractures occur before puberty)
  • smaller than average stature
  • sclera normal in color (i.e., white or near-white)
  • mild to moderate bone deformity
  • tendency toward spinal curvature
  • barrel-shaped rib cage
  • triangular face
  • possible brittle teeth
  • possible hearing loss
  • improperly formed collagen
  • By studying the appearance of OI bone under the microscope, investigators noticed that some people who are clinically within the Type IV group had a distinct pattern to their bone. When they reviewed the full medical history of these people, they found the groups had other features in common. They named these groups Type V and Type VI OI. The mutations causing these forms of OI have not been identified, but people in these two groups do not have mutations in the type 1 collagen genes.

Type VI OI

  • clinically similar to Type IV OI in appearance and symptoms
  • slightly elevated activity level of alkaline phosphatase (an enzyme linked to bone formation), which can be determined by a blood test
  • distinctive “fish-scale” appearance to bone when viewed under the microscope
  • diagnosed by bone biopsy
  • unknown whether this form is inherited in a dominant or recessive manner, but researchers believe the mode of inheritance is most likely recessive
  • eight people identified with this type of OI to date

 

Loading...
Is it Helpful Article?YES10705 Views 0 Comment
I have read the Privacy Policy and the Terms and Conditions. I provide my consent for my data to be processed for the purposes as described and receive communications for service related information.
This website uses cookie or similar technologies, to enhance your browsing experience and provide personalised recommendations. By continuing to use our website, you agree to our Privacy Policy and Cookie Policy. OK