Muscular dystrophy (MD) is an inherited (genetic) disorder of the muscles. It is called a neuromuscular disease. There are several types. Becker muscular dystrophy (BMD) is a rare type. It has milder symptoms than Duchenne muscular dystrophy (DMD), which is more common. BMD causes weakness of skeletal muscles, breathing muscles, and the heart muscle. Over time, the muscle fibers break down.
BMD is a genetic disease. This means it passes from parents to children. It is caused by a faulty gene on the X chromosome. It mostly affects boys. Girls are only carriers and usually don’t have symptoms.
People normally have 23 pairs of chromosomes in each cell of their body. The 23rd pair controls a person’s gender. This pair is 2 X chromosomes for females. The pair is 1 X and 1 Y chromosome for males.
The faulty BMD gene is a recessive gene. This means the gene needs to be on each X chromosome for symptoms of the disease to occur. A girl would need 2 copies--1 copy on each X chromosome. If she has only 1 copy on 1 X chromosome, she is a carrier of the disease but will not have symptoms. Boys only have one X chromosome. If their X chromosome has a faulty gene, they will have symptoms.
A child is more at risk for BMD if he or she has a family member with the disease. Girls are rarely affected by this type of muscular dystrophy.
Symptoms usually start during teen or early adult years. They can include:
The symptoms of Becker muscular dystrophy can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.
The healthcare provider will ask about your child’s symptoms and health history. He or she may also ask about your family’s health history to find out if other family members have had muscular dystrophy. He or she will give your child a physical exam. Your child may also have tests, such as:
Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.
There is no known cure for BMD, or treatment to stop the muscles from weakening. The goal of treatment is to keep muscles as strong as possible to allow a child to function independently.
Treatment choices include:
Talk with your child’s healthcare providers about the risks, benefits, and possible side effects of all treatments.
Children with BMD may have additional health problems, such as:
Your healthcare provider may advise genetic counseling. You can discuss with a counselor the risk for a Becker muscular dystrophy in a future pregnancy.
BMD is a condition that gets worse over time (progressive). It needs life-long management. Walking and sitting often become more difficult as a child grows. In time your child will need a wheelchair in his or her late teen years or early 20s. This is because the leg muscles become too weak to work. In some cases a child may need a wheelchair earlier.
Your child will also need a heart imaging test every 1 to 2 years. This may be a heart echocardiogram or an MRI. These tests look at the function and health of the heart. A child with BMD will need special care during surgery to prevent problems from anesthesia.
People with BMD usually live until their 40s. Problems from cardiomyopathy are a common cause of death.
A healthcare team will work with your family to improve your child's function and to give support as you learn to care for your child's needs.
You can contact the Muscular Dystrophy Association (www.mda.org) for support, resources, and help.
Call the healthcare provider if your child has:
Tips to help you get the most from a visit to your child’s healthcare provider:
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