Muscular Dystrophy
What is Becker muscular dystrophy in children?
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 usually has milder symptoms and occurs later 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. Although skeletal
muscle involvement is generally less severe than in DMD, heart involvement is often
more of a problem with BMD.
What causes Becker muscular dystrophy in a child?
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. One set of
23 chromosomes comes from the mother, and one set of 23 chromosomes comes from the
father. Each chromosome contains many genes. One of these pairs of chromosomes controls
a person’s sex. If this pair is two X chromosomes (XX), then the child is a female.
If this pair is one X and one Y chromosome (XY), then the child is a male.
The faulty BMD gene is an X-linked recessive gene. This means the gene needs to be
on each of her two X chromosomes for symptoms of the disease to occur in girls. She
would need to inherit the faulty gene from both her mother and her father. If she
has only one faulty gene on one X chromosome, she is a carrier of the disease but
will likely not have symptoms. Boys have only one X chromosome, so if their X chromosome
has a faulty gene, they will have symptoms.
Which children are at risk for Becker muscular dystrophy?
Children are more at risk for BMD if they have a family member with the disease. Girls
are rarely affected by this type of muscular dystrophy.
What are the symptoms of Becker muscular dystrophy in a child?
Symptoms usually start during the teen or early adult years. They can include:
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Muscle cramping and feeling weak when exercising
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Trouble walking, running, jumping, climbing stairs
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Falling often
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Muscle pain
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Enlarged calves
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Walking on tips of toes
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Weakness in arms and shoulders
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Tiredness
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Difficulty breathing, especially with heart involvement
The symptoms of BMD can be like other health conditions. Make sure your child sees
their healthcare provider for a diagnosis.
How is Becker muscular dystrophy diagnosed in a child?
The healthcare provider will ask about your child’s symptoms and health history. They
may also ask about your family’s health history to find out if other family members
have had muscular dystrophy. They will give your child a physical exam. Your child
may also have tests, such as:
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Blood tests. These may include genetic blood tests. Some genetic tests can be done with saliva
and don't need blood tests.
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Electromyogram (EMG) and nerve conduction studies. These tests check if muscle weakness is a result of muscle or nerve damage.
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Muscle biopsy. A small sample of muscle tissue is taken and looked at under a microscope.
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Electrocardiogram (ECG). This is a test that records the electrical activity of the heart. It shows abnormal
rhythms (arrhythmias) and detects heart muscle damage.
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Echocardiogram. This is an ultrasound test of the heart muscle. It shows a picture of how strong
the heart muscle is pumping.
How is Becker muscular dystrophy treated in a child?
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 almost always includes several kinds of specialists. It also
includes testing over time, such as imaging, EMG, and heart and pulmonary studies.
Treatment choices include:
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Physical therapy to strengthen muscle and help prevent muscle contractures
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Braces and splints
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The use of steroid medicines, though they can have unwanted side effects
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Surgery to treat contractures
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Medicines for heart disease, bone disease, and respiratory disease when they occur
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Medicines from clinical research trials
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Wheelchair use
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Nutritional counseling
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Psychological counseling
Talk with your child’s healthcare providers about the risks, benefits, and possible
side effects of all treatments.
What are possible complications of Becker muscular dystrophy in a child?
Children with BMD may have additional health problems, such as:
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Heart muscle weakening and not pumping blood well (dilated cardiomyopathy)
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Breathing and lung problems
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Scoliosis, a sideways curving of the back bones (vertebrae)
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Diet, nutrition, and digestive problems
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Trouble focusing, learning, or controlling emotions
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Complications from anesthesia, for which special care is needed
How can I help prevent Becker muscular dystrophy in my child?
Your healthcare provider may advise genetic counseling. You can discuss with a counselor
the risk for BMD in a future pregnancy.
How can I help my child live with Becker muscular dystrophy?
BMD is a condition that gets worse over time (progressive). It needs lifelong management.
Walking and sitting often become more difficult as a child grows. In time, some will
eventually need a wheelchair. This is because the leg muscles become too weak to work.
Often, those with BMD can continue to walk for many years. 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 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
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.
When should I call my child’s healthcare provider?
Call the healthcare provider if your child has:
Key points about Becker muscular dystrophy in children
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Becker muscular dystrophy (BMD) is a rare inherited disorder of the muscles.
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BMD causes weakness of skeletal muscles, breathing muscles, and the heart muscle.
Over time, the muscles may become too tight and pull together painfully.
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Children are more at risk for BMD if they have a family member with the disease. Girls
are rarely affected.
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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.
-
Your healthcare provider may advise genetic counseling. You can discuss with a counselor
the risk of BMD in a future pregnancy.
Next steps
Tips to help you get the most from a visit to your child’s healthcare provider:
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Know the reason for the visit and what you want to happen.
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Before your visit, write down questions you want answered.
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At the visit, write down the name of a new diagnosis, and any new medicines, treatments,
or tests. Also write down any new instructions your provider gives you for your child.
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Know why a new medicine or treatment is prescribed and how it will help your child.
Also know what the side effects are.
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Ask if your child’s condition can be treated in other ways.
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Know why a test or procedure is recommended and what the results could mean.
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Know what to expect if your child does not take the medicine or have the test or procedure.
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If your child has a follow-up appointment, write down the date, time, and purpose
for that visit.
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Know how you can contact your child’s provider after office hours, and on weekends
and holidays. This is important if your child becomes ill and you have questions or
need advice.
Online Medical Reviewers:
- Joseph Campellone MD
- Raymond Kent Turley BSN MSN RN
- Ronald Karlin MD