Muscular Dystrophy

Muscular dystrophy (MD) is a group of more than 30 inherited diseases.

Muscular dystrophy (MD) is a group of more than 30 inherited diseases. They all cause muscle weakness and muscle loss. Some forms of MD appear in infancy or childhood. Others may not appear until middle age or later. The different types can vary in whom they affect, which muscles they affect, and what the symptoms are. All forms of MD grow worse as the person's muscles get weaker. Most people with MD eventually lose the ability to walk.

There is no cure for muscular dystrophy. Treatments can help with the symptoms and prevent complications. They include physical and speech therapy, orthopedic devices, surgery, and medications. Some people with MD have mild cases that worsen slowly. Others cases are disabling and severe.

Genetic counseling may be advised if there is a family history of Becker muscular dystrophy.

Becker muscular dystrophy is very similar to Duchenne muscular dystrophy. The main difference is that it gets worse at a much slower rate and it is less common.

The disorder is passed down through families (inherited). Having a family history of the condition raises your risk.

Becker muscular dystrophy occurs in about 3 to 6 out of every 100,000 births. The disease is found mostly in boys.

Females rarely develop symptoms. Males will develop symptoms if they inherit the defective gene. Symptoms most often appear in boys between ages 5 and 15, but may begin later.

Muscle weakness of the lower body, including the legs and pelvis area, slowly gets worse, causing:

  • Difficulty walking that gets worse over time; by age 25 to 30, the person is usually unable to walk
  • Frequent falls
  • Difficulty getting up from the floor and climbing stairs
  • Difficulty with running, hopping, and jumping
  • Loss of muscle mass
  • Toe walking
  • Muscle weakness in the arms, neck, and other areas is not as severe as in the lower body

Other symptoms may include:

  • Breathing problems
  • Cognitive problems (these do not get worse over time)
  • Fatigue
  • Loss of balance and coordination

The health care provider will do a nervous system (neurological) and muscle exam. A careful medical history is also important, because symptoms are similar to those of Duchenne muscular dystrophy. However, Becker muscular dystrophy gets worse much more slowly.

An exam may find:

  • Abnormally developed bones, leading to deformities of the chest and back (scoliosis)
  • Abnormal heart muscle function (cardiomyopathy)
  • Congestive heart failure or irregular heartbeat (arrhythmia) - rare
  • Muscle deformities, including contractures of heels and legs, abnormal fat and connective tissue in calf muscles
  • Muscle loss that begins in the legs and pelvis, then moves to the muscles of the shoulders, neck, arms, and respiratory system

Tests that may be done include:

  • CPK blood test
  • Electromyography (EMG) nerve testing
  • Muscle biopsy or genetic blood test

There is no known cure for Becker muscular dystrophy. However there are many new drugs currently undergoing clinical testing that show significant promise in treating the disease.The current goal of treatment is to control symptoms to maximize the person's quality of life. Some providers prescribe steroids to help keep a patient walking for as long as possible.

Activity is encouraged. Inactivity (such as bed rest) can make the muscle disease worse. Physical therapy may be helpful to maintain muscle strength. Orthopedic appliances such as braces and wheelchairs may improve movement and self-care.

Genetic counseling may be recommended. Daughters of a man with Becker muscular dystrophy may carry the defective gene and could pass it on to their sons.