What is Muscular Dystrophy?

The muscular dystrophies (MD) are a group of more than 30 genetic diseases, all of which are characterized by degeneration of the skeletal muscles.

The disorders differ in terms of the age of onset, distribution and extent of muscle weakness, rate of progression and pattern of inheritance.

Three types of MD

— Duchenne MD is the most common form of MD. Caused by the absence of dystrophin, the disease primarily affects males. Dystrophin is a protein involved in maintaining the integrity of muscle.

After the onset, which occurs between the ages of 3 and 5, the disorder progresses rapidly.

Girls have a 50 percent chance of inheriting and passing the defective gene to their children.

— Facioscapulohumeral MD often begins in the teenage years. It causes progressive weakness in face, legs and arm muscles and around the shoulders and chest. It progresses slowly and can vary in symptoms from mild to disabling.

— Myotonic MD is the most common adult form of muscular dystrophy and is characterized by prolonged muscle spasms, cardiac abnormalities, cataracts and endocrine disturbances.

Is there any treatment?

There is no specific treatment to stop or reverse any form of MD. Treatment may include physical therapy, respiratory therapy, speech therapy, orthopedic appliances used for support and corrective orthopedic surgery.

Drug therapy includes corticosteroids to slow muscle degeneration, anticonvulsants to control seizures, immunosuppressants to delay some damage to muscle cells and antibiotics to fight respiratory infections.

Some individuals may benefit from occupational therapy and assistive technology. Some patients may need assisted ventilation to treat respiratory muscle weakness and a pacemaker for cardiac abnormalities.

What is the prognosis?

The prognosis for people with MD varies according to the type and progression of the disorder. Some cases may be mild and progress very slowly over a normal lifespan, while others generate severe muscle weakness, functional disability and loss of the ability to walk. Some children with MD die in infancy, while others live into adulthood with only moderate disability.

Information provided by the National Institute of Neurological Disorders and Stroke.

For additional information, please visit http://www.ninds.nih.gov/find_people/groups/mdcc/index.htm.