Symptoms & Types

All people with Osteogenesis Imperfecta (OI) have weak bones, which makes them susceptible to fractures.

Symptoms

All people with Osteogenesis Imperfecta (OI) have weak bones, which makes them susceptible to fractures. People with OI are usually below average height (short stature). However, the severity of the disease varies greatly.

 

The classic symptoms include:

  • blue tint to the whites of the eyes (blue sclera)
  • multiple bone fractures - the frequency of fractures may increase in adolescence
    early hearing loss (deafness).

 

Because collagen is also found in ligaments, people with OI often have loose joints (hypermobility) and flat feet. Some types of OI also lead to the development of poor teeth.

 

Symptoms of more severe forms of OI may include:

  • bowed legs and arms
  • kyphosis (over-curvature of the upper back)
  • scoliosis.

 

OI is a genetic disorder. Most cases (90 percent) involve a change (mutation) in type 1 collagen - the protein 'scaffolding' of bone and other connective tissues. Other cases of OI are caused by changes in other genes in bone development.

Inheritance Patterns

Type I and IV are usually inherited in an autosomal dominant manner but new mutations in a family (sporadic) often occur. Affected families should be referred to a genetics centre for information and support.

 

Prenatal Diagnosis

Severe cases may be detected by ultrasound scanning. A DNA test may be available at eight weeks for some affected families where the genetic mutation is already known.