Transcript Osteogenesis Imperfecta(1)

Meaning: imperfect bone formation
Also Known As:
• Brittle Bone Disease
• Brittle Bone Syndrome
How Common is it?
A range of 25,000 to
50,000 Americans
are affected by OI.
This wide range is
due to the fact that
very mild cases of
OI often go
unnoticed and are
not diagnosed.
Worldwide, about 1
in every 20,000
people have OI.
Generally, it is a
rare disease.
Q: WHAT IS OSTEOGENESIS IMPERFECTA?
A: OI is a genetic disorder
the affects the gene that
produces collagen in your
body. Collagen is a
protein that connects
tissues in your body. It
also helps with the
formation of teeth,
ligaments, and sclera
(white outer tissue of the
eyeball).
By looking at a person, you MAY be
able to tell if they had OI by their
abnormally small stature, the whites of
their eyes being a blue color, they
would have a triangular head shape,
and could potentially be using a
walker, wheelchair, or have casts on at
the time. However, some people with
OI have relatively mild symptoms and
you MAY NOT notice that they look
different in any way.
SYMPTOMS:
 multiple, frequent fractures
 muscle weakness
 joint laxity
 curved bones
 Scoliosis
 brittle teeth
 short stature
 blue sclera
 fragile skin
 triangular head and face shape
 respiratory complications
WHO?
How does OI
affect a
Basedperson’s
on the type life?
of OI, a
person’s lifespan could be affected
very little, while it can also be
drastically affected. There are 8
different types of OI. Similar
symptoms may occur in all types
of OI with varying severity.
Different symptoms may also show
How does OI affect a
CONTIN
UED…
TYPE I: mildest and most common form of disorder; does
not usually affect lifespan unless a severely traumatic event
occurs; most fractures occur during youth and adolescence
TYPES II and III: most severe types; infants with TYPE II
commonly die during pregnancy or shortly after birth ,
however some with TYPE III may survive longer but with
many disabilities and traumatic events
TYPES IV-VII: moderate forms of disease; lifespan not
dramatically affected; more rare than type I and deal with
different genes
TYPE VIII: more severe type similar to types II or III but
some symptoms vary
*There is no certain reduced life expectancy, but with more
severe cases of OI the probability of death from accidental
trauma or respiratory complications is highly increased.
-Respiratory problems and accidental trauma are
the most common deaths of people who have OI.
Can a person be tested
OI?
YES. Testing can take place to
make a diagnosis if a person
is showing symptoms of OI.
Tests can also be planned for
children whose families have
been affected by OI. Testing
and diagnosis is usually done
during childhood, and a
diagnosis can sometimes be
made during pregnancy.
Methods of testing include:
o X-Rays
o DNA sequencing using a collagen
sample from blood
o Biochemical tests using a
collagen sample from the skin
o tests during pregnancy can be
done through ultrasound and
amniocentesis
for
How is OI treated?
There is no cure for OI as of right
now. However, there are some
ways of dealing with the disorder.
Biophosphonates and other
medicines are used to make bones
stronger and more dense, and
surgically placing rods in the
bones of the legs often help
prevent major fractures. There are
minor symptoms of the
biophosphonates, including
stomach upset and heartburn. On
a regular basis, doctors and
families focus on mobility and
safe exercise such as swimming
and physical therapy, as well as
keeping fracture numbers to a
minimum. Braces, wheelchairs,
and casts are useful aids as well.
Support Groups
The Osteogenesis
Imperfecta Foundation
is a major organization
that helps educate
people about OI. It also
gives reference to
several people whom
you can contact about
local support groups
near you.
Inheritance Patterns and Gene Location
Dominant or Recessive?
About 85%-90% of OI
cases that are inherited
are inherited in dominant
manner. There are some
rare instances where the
disorder is recessive an
autosomal however. The
different inheritance
patterns may also deal
with slightly different
genes.
35% of OI cases are a
result of spontaneous
mutations, while the
others come from
parents affected by OI
or parents who are
carriers.
The mutations that
cause collagen
problems can affect
either the quantity of
collagen or the
quality of the
collagen produced.
Inheritance Patterns and Gene Location
Continued…
The gene for Osteogenesis
Imperfecta is located on
chromosome 17 which has 81
million base pairs.
INTERESTING FACTS
*Parents of children
with OI are often
accused of child
abuse, which is why
they are advised
always to carry a
document stating
their child’s
condition so that
their kids aren’t
taken from them at
any point.
*OI was
recognized in an
Egyptian mummy
that is dated
back to 1000 BC.
*OI does not affect
fertility.
*The 2 forms of OI
that are inherited
recessively were
discovered only 4
year ago.
oif.org
genome.gov
orthoinfo.aaos.org
Dnarss.com
Ghr.nlm.nih.gov