Duchenne vs. Becker Muscular Dystrophy: Understanding the Differences
Key takeaways:
Muscular dystrophies are a group of conditions that affect all the muscles in the body.
People with Duchenne or Becker muscular dystrophy have a mutation in the gene that controls how the body makes dystrophin. Dystrophin is a major building block of muscle tissue.
There’s no cure for muscular dystrophy, but newer treatments, including gene therapy, are helping people live longer, healthier lives.
Muscular dystrophy is a term used to describe more than 30 genetic conditions. Not all muscular dystrophies are the same, but they all affect the muscles throughout the body.
People with muscular dystrophy develop muscle weakness over time. This affects how people are able to do everyday activities like walking, eating, and even breathing. Muscular dystrophy can also affect the heart muscle, making it harder for people to move blood to other parts of their body.
Duchenne and Becker muscular dystrophy are two well-known types of muscular dystrophy. They’re closely related but not the same. Here’s what to know about the differences between Duchenne and Becker muscular dystrophy.
What causes Duchenne vs. Becker muscular dystrophy?
Both Duchenne and Becker muscular dystrophy are caused by a mutation in the DMD gene.
The DMD gene is one of the largest human genes. This gene carries the instructions the body uses to make dystrophin. Dystrophin is a protein found in all the muscles in the body, including the muscles in the heart. There’s also a small amount of dystrophin in the brain and nerves.
Without working DMD genes, the body can’t make enough dystrophin. And without dystrophin, muscles can’t work properly.
People are born with either one or two DMD genes, which is found on the X chromosome.
If someone is born with a DMD mutation and they only have one DMD gene (one X chromosome), they’ll not make enough dystrophin and they’ll develop muscular dystrophy.
People born with a DMD mutation and two X chromosomes can inherit one normal DMD gene and one abnormal DMD gene. They’re still able to make enough dystrophin to support their muscles so they develop few, if any, symptoms.
People with two X chromosomes who inherit two DMD mutations will develop muscular dystrophy. But this situation is very uncommon.
So people are more likely to develop Duchenne or Becker muscular dystrophy if they only have one X chromosome.
How common is Duchenne vs. Becker muscular dystrophy?
Duchenne muscular dystrophy is about three times more common than Becker muscular dystrophy.
But both conditions are relatively rare. In the United States, the CDC has found that these conditions occur in about 1 out of every 5,000 males between the ages of 5 and 9.
What are the symptoms of Duchenne vs. Becker muscular dystrophy?
People who have Duchenne and Becker muscular dystrophy both experience similar symptoms because of muscle weakness.
But people with Becker muscular dystrophy make more dystrophin than people with Duchenne. So people with Duchenne will have more severe symptoms than people with Becker.
For example, over time people with Duchenne muscular dystrophy will not be able to walk on their own after childhood. But people with Becker may be able to walk or walk with some assistance until adulthood. But they’ll have trouble with running and may experience frequent falls. Both groups also develop weakness in their arms and hands, which affects their ability to do everyday tasks.
Over time, people with Duchenne and Becker develop heart weakness and heart failure.
How do you diagnose Duchenne vs. Becker muscular dystrophy?
Both Duchenne and Becker muscular dystrophy can be diagnosed with gene testing.
Parents and healthcare providers may notice symptoms like frequent falls, trouble running, and other signs of muscle weakness when a child is still very young. It can be hard to know whether these are signs of a muscular dystrophy or simply a slowed pattern of physical development.
Often, healthcare providers will order a simple blood test called creatinine kinase. This test may show signs of muscular dystrophy. If the creatinine kinase level is high, then genetic testing will be done to confirm whether a person has muscular dystrophy.
The bottom line
Duchenne and Becker muscular dystrophy are two types of muscular dystrophy that affect the muscles in the heart and the rest of the body. People with Duchenne and Becker muscular dystrophy develop muscle weakness, which affects their ability to walk, move, and complete everyday tasks. Over time, they also develop muscle weakness. People with Duchenne muscular dystrophy have more severe symptoms than people with Becker muscular dystrophy.
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References
Caudal, D., et al. (2020). Characterization of brain dystrophins absence and impact in dystrophin-deficient Dmdmdx rat model. Public Library of Science One.
Centers for Disease Control and Prevention. (2022). MD STARnet data and statistics.
Kennedy Krieger Institute. (n.d.). Duchenne and Becker muscular dystrophy (DMD/BMD).
MedlinePlus. (n.d.). DMD gene.
Muscular Dystrophy Association. (n.d.). Duchenne muscular dystrophy (DMD).
National Institute of Neurological Disorders and Stroke. (2023). Muscular dystrophy.
Venugopal, V., et al. (2023). Duchenne muscular dystrophy. StatPearls.
