OI is caused by genetic defects that
affect the body’s ability to make strong bones. In
dominant (classical) OI, a person has too little
type I collagen or a poor quality of type I collagen
due to a mutation in one of the type I collagen
genes. Collagen is the major protein of the body’s
connective tissue. It is part of the framework that
bones are formed around. In recessive OI, mutations
in other genes interfere with collagen production.
The result in all cases is fragile bones that break
There is not yet a cure for OI.
Treatment is directed toward preventing or
controlling the symptoms, maximizing independent
mobility, and developing optimal bone mass and
muscle strength. Care of fractures, extensive
surgical and dental procedures, and physical therapy
are often recommended for people with OI. Use of
wheelchairs, braces, and other mobility aids is
common, particularly (although not exclusively)
among people with more severe types of OI.
Despite numerous fractures,
restricted physical activity, and short stature,
most adults and children with OI lead productive and
successful lives. They attend school, develop
friendships and other relationships, have careers,
raise families, participate in sports and other
recreational activities and are active members of
The prognosis for a person with OI
varies greatly depending on the number and severity
of symptoms. Respiratory failure is the most
frequent cause of death for people with OI, followed
by accidental trauma.