Osteogenesis
Imperfecta
Osteogenesis imperfecta
(OI), also known as brittle-bone disease, is a genetic
(inherited) disorder characterized by bones that break
easily without a specific cause. An estimated 20,000 to
50,000 people in the US have this disease. OI can affect
males and females of all races.
What causes osteogenesis
imperfecta?
The cause of OI is
believed to be due to a genetic defect that causes
imperfectly-formed, or an inadequate amount of, bone
collagen - a protein found in the connective
tissue.
What are the types and
symptoms of OI?
The following are the most
common symptoms for osteogenesis imperfecta. However,
each individual may experience symptoms differently.
Although symptoms may vary, generally they are used to
classify the four forms of OI, each of which represents
the severity of the condition.
According to the
Osteoporosis and Related Bone Diseases National Resource
Center, part of the National Institutes of Health (NIH),
the types of OI and their symptoms include the
following:
|
Type I: |
- most common
- mildest form
- bones fracture easily
- can usually be traced through the
family
- near normal stature or slightly
shorter
- blue sclera (the normally white area
of the eye ball)
- dental problems (brittle teeth)
- hearing loss beginning in the early
20s and 30s
- most fractures occur before puberty;
occasionally women will have fractures after
menopause
- triangular face
- tendency toward spinal curvatures
|
|
Type II: |
- most severe form
- newborns severely affected;
frequently fatal, although a few have lived to
adulthood
- severe bone deformity with many
fractures
- usually resulting from a new gene
mutation
- very small stature with extremely
small chest and under-developed lungs
|
|
Type III: |
- bones fracture very easily
- bone deformity
- tend to be isolated family incidents
- very small in stature
- fractures at birth very common
- x-ray may reveal healing of
fractures that occurred while in the uterus
- may have hearing loss
- loose joints and poor muscle
development in arms and legs
- barrel-shaped rib cage
- triangular face
- spinal curvature
- possible respiratory
problems
|
|
Type IV: |
- between Type I and Type III in
severity
- can frequently be traced through the
family
- bones fracture easily - most before
puberty
- normal or near-normal colored sclera
- problems with teeth
- spinal curvatures
- possible hearing loss
|
The symptoms of
osteogenesis imperfecta may resemble other medical
conditions or problems. Always consult your physician
for a diagnosis.
How is osteogenesis
imperfecta diagnosed?
In addition to a complete
medical history and physical examination, diagnostic
procedures for osteogenesis imperfecta may include a
skin biopsy to evaluate the amount and structure of
collagen. However, this test is complicated and not many
qualified facilities are available to perform the
procedure. It is not unusual for results of the biopsy
to take up to six months.
Additional diagnostic
tests may include:
- x-ray - a
diagnostic test which uses invisible electromagnetic
energy beams to produce images of internal tissues,
bones, and organs onto film
- an examination
of the ear, nose, and throat (to detect hearing
loss)
Treatment for
osteogenesis imperfecta:
Specific treatment for
osteogenesis imperfecta will be determined by your
physician based on:
- your age, overall
health, and medical history
- extent of the disease
- your tolerance for
specific medications, procedures, or therapies
- expectations for the
course of the disease
- your opinion or
preference
To date, there is no known
treatment, medicine, or surgery that will cure
osteogenesis imperfecta (OI). The goal of treatment is
to prevent deformities and fractures and allow the child
to function as independently as possible. Treatments for
preventing or correcting symptoms may
include:
- care of
fractures
- surgery
- rodding - a procedure
to insert a metal bar the length of a long bone to
stabilize it and prevent deformity.
- dental
procedures
- physical therapy
- assistive devices, such as
wheelchairs, braces, and other custom-made equipment
Management of
osteogenesis imperfecta (OI):
Management of the disease
includes focusing on preventing or minimizing
deformities, and maximizing the individual's functional
ability at home and in the community. Management of OI
is either non-surgical or surgical. Non-surgical
interventions may include one or more of the
following:
- physical therapy
- positioning aids (to help sit,
lie, or stand)
- braces and splints (to prevent
deformity and promote support or protection)
- medications
- psychological counseling
Surgical interventions may
be considered to manage the following
conditions:
- fractures
- bowing of bone
- scoliosis - a lateral, or
sideways curvature and rotation of the back bones
(vertebrae), giving the appearance that the person is
leaning to one side.
- heart problems
Surgery may also be
considered to maintain the ability to sit or
stand.
Long-term outlook for an
individual with osteogenesis imperfecta
(OI):
Osteogenesis imperfecta
(OI) is a progressive condition that needs life-long
management to prevent deformity and complications. The
interdisciplinary healthcare team helps the family to
improve the functional outcomes and to provide support.
The Osteogenesis Imperfecta Society can also be an
important resource.