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Introduction to Muscular Dystrophies and Related Disorders


Michael Rubin

, MDCM, New York Presbyterian Hospital-Cornell Medical Center

Last full review/revision Jul 2020| Content last modified Jul 2020
Click here for the Professional Version

Muscular dystrophies are a group of inherited muscle disorders in which one or more genes needed for normal muscle structure and function are defective, leading to muscle weakness of varying severity. Muscle fibers appear deteriorated (dystrophic) when viewed under a microscope. Facioscapulohumeral dystrophy is the most common form of muscular dystrophy. Duchenne muscular dystrophy and Becker muscular dystrophy are the second most common forms. Duchenne muscular dystrophy is a more severe form. Becker muscular dystrophy is closely related to Duchenne dystrophy but starts later in a child's life and causes milder symptoms.

Other inherited muscle disorders include congenital myopathies, myotonia congenita, familial periodic paralysis, and glycogen storage diseases. Glycogen storage diseases are a group of rare inherited disorders in which muscles cannot metabolize sugars normally, so they build up large stores of glycogen (a starch that is formed from sugars).

Congenital muscular dystrophy

Congenital muscular dystrophy is not a single disorder but instead refers to muscular dystrophy that is present at birth.

Congenital muscular dystrophies result from mutations in a variety of different genes, including the genes needed for normal muscle structure and function.

Newborns who have a congenital muscular dystrophy have severely reduced muscle tone (hypotonia, or "floppiness").

Doctors suspect the diagnosis of congenital muscular dystrophy in any newborn who has floppy muscle tone. Doctors usually do a muscle biopsy and genetic testing to confirm the diagnosis.


  • Physical therapy

Treatment of congenital muscular dystrophy includes physical therapy, which may help maintain muscle function.

More Information

The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
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