Download Duchenne Muscular Dystrophy - SSSD-Bio

Duchenne Muscular Dystrophy
Michaela Shaffer
Periods 1 and 2
Genetic Disorders
Define
the most common of several childhood muscular
dystrophies, it is an inherited disorder (X-linked
recessive) with progressive degeneration of muscle,
onset is generally before age 6 years
People with DMD lose muscle
all there lives, but it is
usually not noticed until a
parent or caretaker finds
unusual walking and/or
talking around the age of
3
Incidence Rates
Although girls rarely get this disease, females can still have some
of the symptoms like weaker muscles in the back, legs and
arms that fatigue easily. Some may need a wheelchair or other
mobility aids. Carriers may have heart problems, and
can have shortness of breath or failure to do
moderate exercise. The heart problems, if untreated, can be
quite serious, even life-threatening
*About 1 in every 3,500 boys is born with DMD*
The figure shown below is
the pictorial representation
of the incidence of DMD in
boys.
The figure shown above is the
pictorial representation of the
incidence of DMD.
Cause
DMD is caused by a
mutation in the
gene that produces
an important
muscle protein
called dystrophin,
which is not produced
The Muscle-Fiber
Membrane
Muscles are made up of
bundles of fibers (cells). A
group of interdependent
proteins along the membrane
surrounding each fiber helps
to keep muscle cells working
properly. When one of these
proteins, dystrophin, is
absent, the result is
Duchenne muscular
dystrophy.
How boys are affected
How girls are affected
Alternative Names
Symptoms
Early
o
Delayed Onset Walking
o
Difficulty in performing a standing
jump
o
Waddling when walking
o
Difficulty standing up
o
Enlarged Calves
Later
oDifficulty getting up from
a chair
oLoss of ability to climb
stairs
oWide gaited walk w/
balance problems
More Symptoms
• Fatigue
• Mental retardation (possible, but does not worsen over
time)
• Muscle weakness
▫ Begins in legs and pelvis, also occurs less severely in the
arms, neck, and other areas of the body
▫ Difficulty with motor skills (running, hopping, jumping)
▫ Frequent falls
▫ Rapidly worsening weakness
• Progressive difficulty walking. Ability to walk may be lost
by age 12
• By age 10, the person may need braces for walking. By age
12, most patients are confined to a wheelchair.
Possible Complications
•
•
•
•
•
•
•
•
•
•
Cardiomyopathy
Congestive heart failure (rare)
Deformities
Heart arrhythmias (rare)
Mental impairment (varies,
usually minimal)
Permanent, progressive
disability
Decreased mobility
Decreased ability to care for self
Pneumonia or other respiratory
infections
Respiratory failure
Treatment
Treatment varies on your child's age, overall health,
and medical history the extent of the condition the type of
condition your child's tolerance for specific
medications, procedures, or therapies
expectations for the course of the condition your
opinion or preference
Treatment
Can include...
•physical therapy
•positioning aids - used to help the
child sit, lie, or stand
•braces and splints - used to
prevent deformity, promote
support, or provide protection
•medications
•nutritional counseling
•psychological counseling
Treatment
There is no cure yet for DMD, however case and symptom management is
currently “successful”
Right now there are many clinical trials in process, like administering
Albuterol (beta adrenergic receptor agonist drug that increases strength and
muscle mass) also, they want to treat with Utrophin (sometimes can be
substituted for dystrophin)
Embryonic stem cell transplants is another treatment they are looking
into. It is hoped that injecting healthy, nonspecialized stem cells into
DMD victims will cause the stem cells to specialize and produce
structurally and functionally correct dystrophin. If dystrophin can be
produced, it may slow the progression of the disease, or cure it altogether.
All in all,
what
really kills
the people affected
by DMD is the
failure of
the heart
muscles…
(death usually
occurs by age 25)
Support Groups
•Duchenne Muscular Dystrophy Support
Group
• MDA (Muscular Dystrophy Association
Works Cited
http://depts.washington.edu/pwdlearn/web/glossary/glossary.htm
http://www.mda.org/publications/fa-dmdbmd-family.html
http://health.nytimes.com/health/guides/disease/duchenne-musculardystrophy/overview.html
http://www.ikm.jmu.edu/Buttsjl/ISAT493/Duchenne%20Muscular%20Dy
strophy/duchennesymptoms.html
http://genetics.kaiser.org/home/genetics101highlights.htm
http://www.nlm.nih.gov/medlineplus/ency/imagepages/19097.htm