About
Muscular Dystrophy
The muscular dystrophies are a
group of genetic diseases characterized by progressive weakness
and degeneration of the skeletal muscles that control movement.
There are many forms of muscular dystrophy, some noticeable at
birth (congenital muscular dystrophy), others in adolescence
(Becker Muscular Dystrophy), but the 3 most common types are
Duchenne, facioscapulohumeral, and myotonic.
These three types differ in
terms of pattern of inheritance, age of onset, rate of
progression, and distribution of weakness.
Duchenne Muscular Dystrophy
primarily affects boys and is the result of mutations in the
gene that regulates dystrophin - a protein involved in
maintaining the integrity of muscle fiber. Onset is between 3-5
years and progresses rapidly. Most boys become unable to walk
at 12, and by 20 have to use a respirator to
breathe.
Facioscapulohumeral Muscular
Dystrophy appears in adolescence and causes progressive
weakness in facial muscles and certain muscles in the arms and
legs. It progresses slowly and can vary in symptoms from mild
to disabling.
Myotonic Muscular Dystrophy
varies in the age of onset and is characterized by myotonia
(prolonged muscle spasm) in the fingers and facial muscles; a
floppy-footed, high-stepping gait; cataracts; cardiac
abnormalities; and endocrine disturbances.Individuals with
myotonic Muscular Dystrophy have long faces and drooping
eyelids; men have frontal baldness.
Treatment
There is no specific treatment
for any of the forms of Muscular Dystrophy. Respiratory
therapy, physical therapy to prevent painful muscle
contractures, orthopedic appliances used for support, and
corrective orthopedic surgery may be needed to improve the
quality of life in some cases. Cardiac abnormalities may
require a pacemaker.
Corticosteroids such as
prednisone can slow the rate of muscle deterioration in
patients with Duchenne Muscular Dystrophy but causes side
effects. Myotonia is usually treated with medications such as
mexiletine, phenytoin, or quinine.
Prognosis
The prognosis of Muscular
Dystrophy varies according to the type of Muscular Dystrophy
and the progression of the disorder. Some cases may be mild and
progress very slowly over a normal lifespan, while other cases
may have more marked progression of muscle weakness, functional
disability, and loss of the ability to walk. In Duchenne
Muscular Dystrophy, death usually occurs in the early
20s.
Research
Public Health Authorities
support a broad program of research on Muscular Dystrophy. The
goals of these studies are to understand Muscular Dystrophy and
to develop techniques to diagnose, treat, prevent, and
ultimately cure muscular dystrophy.
Reference for
Muscular Dystrophy Article
National
Institutes of Health
Health
Related Websites
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Institute
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Institute
The National Heart, Lung,
and Blood Institute
National Institute on
Aging
National Institute of
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National Institute of
Arthritis and Musculoskeletal and Skin Diseases
National Institute of
Diabetes and Digestive and Kidney Diseases
National Institute on Drug
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National Institute of Mental
Health
National Institute of
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