Definition

Duchenne muscular dystrophy (DMD) is a genetic disease. The main sign of DMD is muscle weakness that worsens over time. Before age five, the muscles in the legs, arms, and trunk begin to weaken. Later in the disease, the heart and respiratory muscles weaken.

Causes

DMD is caused by a genetic mutation. The mutation causes the gene to make inadequate amounts of a protein called dystrophin. This protein is needed to keep muscles intact.

Risk Factors

These factors increase your child’s chance of having DMD:

    
  • Family history
  • Male
  • Symptoms

    Symptoms of DMD may include:

        
  • Child is late in learning to walk
  • Larger than normal calf muscles
  • Frequent falls
  • Clumsy walking
  • Difficulty climbing stairs
  • Trouble running
  • Walking on toes or balls of feet
  • Trouble with balance
  • Walking with shoulders back and belly out
  • Trouble keeping up with friends when playing
  • Learning disabilities
  • Contracture of the Hand

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    © Nucleus Medical Media, Inc.

    Diagnosis

    Your doctor will ask about your child’s symptoms and medical history. A physical exam will be done. Your doctor will also ask if there is any family history of neuromuscular disease. The exam will focus on your child’s muscles. The doctor will look for signs of weakness. You will likely be referred to a specialist.

    Your child's bodily fluids and tissues may be tested. This can be done with:

        
  • Muscle biopsy
  • Blood tests
  • Your child's nerves and muscles may be tested. This can be done with electromyography (EMG).

    EMG of the Shoulder

    EMG shoulder 2

    © Nucleus Medical Media, Inc.

    Treatment

    Talk with your doctor about the best plan for your child. The disease worsens over time. Your child may need different treatments as the disease progresses. Options include the following:

    Physical Therapy

    Therapy plays a large role in treating DMD. Your child will work with a therapist to try to keep muscles strong.

    The disease causes contractures. This is when a muscle shortens, making it difficult to move. The therapist will focus on preventing this with range of motion exercises.

    Scoliosis is common in DMD. Exercises can help to keep the back as straight as possible.

    Assistive Devices

    Braces are used to keep the legs straight and prevent contractures. A walker and wheelchair may be needed later when the leg muscles become too weak to walk.

    Medications

    Your doctor may prescribe a steroid medication like prednisone. This can help to improve muscle strength and slow muscle weakening. Steroids can weaken bones. To keep bones healthy, your child will take vitamin D and calcium supplements. If your child has heart problems, medications may be given to slow the damage.

    Respiratory Therapy

    As the disease progresses, the muscles that support breathing may weaken. Your child may need a ventilator. It will deliver air through a mask, tube, or sometimes through a surgical hole in the windpipe called a tracheotomy.

    Surgery

    Surgery is sometimes used to treat symptoms of DMD. For severe contractures, surgery may be done to release specific tendons. Scoliosis can sometimes interfere with your child’s breathing. In this case, back surgery may be done.

    Prevention

    There are no known guidelines to prevent this progressive muscle disease.