Introduction to Muscular Dystrophies and Related Disorders

ByMichael Rubin, MDCM, New York Presbyterian Hospital-Cornell Medical Center
Reviewed/Revised Jan 2024
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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. Duchenne muscular dystrophy and Becker muscular dystrophy are the most common muscular dystrophies. 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. Myotonic dystrophy is the second most common, and facioscapulohumeral dystrophy is the third.

Other forms of muscular dystrophy include Emery-Dreifuss dystrophy, limb-girdle dystrophy, and congenital dystrophies.

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). Mitochondrial disorders affect the muscles as well as other parts of the body.

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.

Treatment

  • Physical therapy

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

More Information

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

  1. Muscular Dystrophy Association: Information on research, treatment, technology, and support for people living with a muscular dystrophy or with congenital muscular dystrophy

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