Osteogenesis Imperfecta(1)

7/29/2019 Osteogenesis Imperfecta(1)

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Meaning: imperfect bone formation

Also Known As:

Brittle Bone Disease

Brittle Bone Syndrome


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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 ofOI often go

unnoticed and are

not diagnosed.

Worldwide, about 1

in every 20,000

people have OI.Generally, it is a

rare disease.


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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).

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

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, theywould 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 lookdifferent in any way.


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WHO?


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HowdoesOI

affecta personslife?BasedonthetypeofOI,apersonslifespancouldbeaffectedverylittle,whileitcanalsobedrasticallyaffected.Thereare8

differenttypesofOI.SimilarsymptomsmayoccurinalltypesofOIwithvaryingseverity.

Differentsymptomsmayalsoshow


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HowdoesOIaffectaCONTINUED

TYPE I: mildest and most common form of disorder; doesnot 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 withmany 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 butsome 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 arethe most common deaths of people who have OI.


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Can a person be tested forOI? How is OI treated?

YES. Testing can take place tomake a diagnosis if a personis showing symptoms of OI.Tests can also be planned forchildren whose families havebeen affected by OI. Testing

and diagnosis is usually doneduring childhood, and adiagnosis can sometimes bemade 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 andamniocentesis

There is no cure for OI as of rightnow. However, there are someways of dealing with the disorder.Biophosphonates and othermedicines are used to make bonesstronger and more dense, andsurgically placing rods in thebones of the legs often helpprevent major fractures. There areminor symptoms of thebiophosphonates, including

stomach upset and heartburn. Ona regular basis, doctors andfamilies focus on mobility andsafe exercise such as swimmingand physical therapy, as well askeeping fracture numbers to aminimum. Braces, wheelchairs,

and casts are useful aids as well.


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Support Groups

The OsteogenesisImperfecta Foundation

is a major organizationthat helps educatepeople about OI. It alsogives reference to

several people whomyou can contact aboutlocal support groupsnear you.


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35% of OI cases are aresult of spontaneous

mutations, while the

others come from

parents affected by OI

or parents who are

carriers.

Inheritance Patterns and Gene Location

Dominant or Recessive?

About 85%-90% of OI

cases that are inheritedare inherited in dominant

manner. There are some

rare instances where the

disorder is recessive an

autosomal however. The

different inheritancepatterns may also deal

with slightly different

genes.

The mutations that

cause collagen

problems can affect

either the quantityof

collagen or the

qualityof the

collagen produced.


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Inheritance Patterns and Gene LocationContinued

The gene for Osteogenesis

Imperfecta is located on

chromosome 17 which has 81

million base pairs.


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INTERESTING FACTS

*Parents of childrenwith OI are often

accused of child

abuse, which is why

they are advisedalways to carry a

document stating

their childs

condition so that

their kids arent

taken from them at

any point.

*OI does not affect

fertility.

*OI was

recognized in anEgyptian mummy

that is dated

back to 1000 BC.

*The 2 forms of OIthat are inherited

recessively were

discovered only 4

year ago.


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oif.org

genome.gov

orthoinfo.aaos.org

Dnarss.com

Ghr.nlm.nih.gov

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Osteogenesis Imperfecta(1)