What Is Duchenne Muscular Dystrophy?

Written by Rachel Reiff Ellis
Medically Reviewed by Christopher Melinosky, MD on November 04, 2025
13 min read

Duchenne muscular dystrophy (DMD) is a condition that makes muscles weaker over time, specifically those you use to move, breathe, and those that help your heart function. It's caused by flaws in the gene that controls how the body keeps muscles healthy.

The disease almost always affects boys, and symptoms usually begin early in childhood. Children with DMD have a hard time standing up, walking, and climbing stairs. Many eventually need wheelchairs to get around. They can also have heart and lung problems.

DMD is rare, affecting fewer than 50,000 people in the U.S., or about 1 out of every 3,600 boys born. Although there isn't a cure, the outlook for people with DMD is better than it has ever been. Years ago, children with the disease usually didn't live beyond their teens. Today, they live into their 30s, and sometimes into their 40s and 50s. There are therapies that can ease symptoms, and researchers are looking for new ones as well.

Muscular dystrophies are a group of diseases that make various muscles weaker and less flexible over time. Duchenne muscular dystrophy is the most common type, and the most severe. 

 

 

DMD is caused by a problem in one of your genes. Genes contain the information your body needs to make proteins, which carry out many different body functions.

If you have DMD, the gene that makes a protein called dystrophin is broken. This protein normally keeps muscles strong and protects them from injury. Having low levels of dystrophin makes your muscles weak, and they start to break down. Over time, these muscle cells die and get replaced with fat and scar tissue. This makes it harder to move. 

The condition is more common in boys because of the way parents pass DMD genes to their children. It's what scientists call a sex-linked disease because it's connected to the groups of genes, called chromosomes, that determine if a baby is a boy or a girl. 

DMD is linked to the X chromosome. Since girls have two X chromosomes, if one of them has DMD, the second X can kick in as a backup, and they don't get the disease. Girls are typically carriers and get the disease only if both of their X chromosomes have the gene change that causes DMD; and even then, they have less severe symptoms. Boys have one X and one Y, so if their X chromosome has the DMD gene change, they'll have the disease.

It's rare, but sometimes people who don't have a family history of DMD get the disease when their genes get defects on their own.

If your child has DMD, you'll probably notice the first signs before they turn 6 years old. Muscles in the legs are usually some of the first affected, so they'll probably start to walk much later than other children their age. 

Once they can walk, they may fall down often and have trouble climbing stairs or getting up from the floor. A symptom called Gower's maneuver is when children with DMD walk their hands up their legs to help themselves stand. Typically, kids with DMD don't walk before about 15 months. After a few years, they might also begin to waddle or walk on their toes.

Other symptoms include:

  • Difficulty lifting their head or weak neck muscles
  • A hard time walking, running, or climbing stairs
  • Not speaking as well as other children their age
  • Calves that look bigger than normal (pseudohypertrophy)
  • Walking with legs apart, on toes, or waddling
  • Walking with their chest pointed out (or has a swayback, saddle back, or arched back)

DMD also can damage the heart, lungs, and other parts of the body. As they get older, your child might have other symptoms, including:

  • A curved spine, also called scoliosis
  • Shortened, tight muscles in their legs, called contractures
  • Headaches
  • Problems with learning and memory
  • Shortness of breath
  • Sleepiness
  • Trouble concentrating

The muscle problems can cause cramps at times, but in general, DMD isn't painful. Your child will still have control of their bladder and bowels. Although some children with the disorder have learning and behavior problems, DMD can have an effect on intellectual ability, but it's usually not significant.

You should let your child's doctor know about the symptoms you've noticed. They'll want to know your child's medical history, then ask questions about their symptoms, like:

  • How old was your child when they started walking?
  • How well do they do things like run, climb stairs, or get up from the floor?
  • How long have you noticed these problems?
  • Does anyone else in your family have muscular dystrophy? If so, what kind?
  • Do they have any trouble breathing?
  • How well do they pay attention or remember things?

The doctor will give your child a physical exam, and they may do some tests to rule out other conditions that can cause muscle weakness.

If the doctor suspects DMD, they'll do some other tests, including:

  • Blood tests. The doctor will take a sample of your child's blood and test it for creatine kinase (CK), an enzyme that your muscles release when they are damaged. A high CK level is a sign that your child could have DMD.
  • Gene tests. Doctors can also test the blood sample to look for a change in the dystrophin gene that causes DMD. Girls in the family can get the test to see if they carry this gene.
  • Muscle biopsy. Using a needle, the doctor removes a tiny piece of your child's muscle. They'll look at it under a microscope to check for low levels of dystrophin, the protein that is missing in people with DMD.
  • Electrodiagnostic tests. Specialists can use machines that measure electrical signals in individual nerves to get a better idea of how well they function and an electromyography to see how the muscle reacts. 

Your doctor may want to do other tests to look at other parts of your child's body that could be affected if they have DMD. They might get images of the heart and spine using MRI or CT scans, or they may do an electrocardiogram to check your child's heart rhythms. 

 

There's no cure for DMD, but medicines and other therapies can ease your child's symptoms and help protect their muscles, heart, and lungs.

Steroid medications

In 2017, the FDA approved the first corticosteroid to treat DMD. Deflazacort (Emflaza) is a pill you take by mouth that has been found to help patients keep muscle strength for longer as well as help them maintain their ability to walk. Common side effects include puffiness, increased appetite, and weight gain.

Steroids such as prednisone curb inflammation and slow muscle damage. Children who take this medicine are able to walk for two to five years longer than they would without it. The drugs also can help your child's heart and lungs work better.

A unique type of steroid drug, vamorolone (Agamree), is also available for kids and teens with DMD. It helps reduce inflammation without many of the side effects of other steroids. 

Steroid alternatives

In 2024, the FDA approved the first nonsteroidal drug called givinostat (Duvyzat) to treat children and adolescents with DMD. It targets an enzyme involved in muscle growth and regrowth. It's been shown to slow the progression of DMD and help users get around better.

Gene-based therapies

Delandistrogene moxeparvovec (Elevidys) was the first FDA-approved gene therapy. Doctors only prescribe it to people who have a mutation in the DMD gene. It delivers a protein to muscles in the skeleton, heart, and lungs that can help make up for some of the missing dystrophin. You take it as a single-dose IV infusion at a treatment center. 

For the small number of people with DMD with a gene mutation that can be treated by skipping a certain section of genetic code called exon 45, doctors can prescribe the injectable drug casimersen (Amondys 45). It was the first targeted treatment for this type of mutation and has been shown to help increase the production of dystrophin.

A few children with DMD have a mutation that reacts well to exon 53 skipping. The drugs golodirsen (Vyondys 53) and viltolarsen (Viltepso) create a different type of dystrophin that's shorter but still works, which increases the amount of it in the muscle fibers. 

The FDA approved eteplirsen (Exondys 51) to treat people with a specific mutation of the gene that leads to DMD. It is an injection medication. Its most common side effects are balance problems and vomiting. Eteplirsen increases production of a shorter version of the dystrophin protein that should work and slow progression.

Other therapies

Because DMD can cause heart problems, it's important for your child to see a heart doctor, called a cardiologist, for checkups once every two years until age 10 and once a year after that. Girls and women who carry the gene have a higher risk of heart problems, too. They should see a cardiologist in their late teens or early adult years to check for any problems.

Some blood pressure medicines may help protect against muscle damage in the heart.

Kids with DMD might need surgery to fix shortened muscles, straighten the spine, or treat a heart or lung problem.

Scientists continue to look for new ways to treat DMD in clinical trials. These trials test new drugs to see if they are safe and if they work. They often are a way for people to try new medicine that isn't available to everyone. Your doctor can tell you if one of these trials might be a good fit for your child.

Most complications of DMD happen because of muscle weakness getting worse over time. Many of them affect the heart and lungs, and can become life-threatening. These include:

Cardiomyopathy. This is a disease of the heart muscle. Diseases of the heart and blood vessels are the leading cause of death in people with DMD. People with DMD can get dilated cardiomyopathy (weak heart muscle) and abnormal heart rhythms as a result of their condition. 

Respiratory failure. When the muscles that support breathing get weak enough that they can't work correctly, it gets harder to breathe and you may need to use assistive devices to get enough oxygen to your body. 

Scoliosis. As the muscles that support the spine grow weak, the spine can start to curve, causing scoliosis. This often gets worse as your child gets less able to get around well. Your child may need a brace or other orthopedic device to help with posture.

Fractures. DMD can cause weak bones (osteoporosis), especially if your child is taking steroid treatments. The most common types of fractures in people with DMD are in the leg, including the femur, tibia, and fibula.

It can feel overwhelming to learn that your child has DMD. Remember that the disease doesn't mean they can't go to school, play sports, and have fun with friends. If you stick with their treatment plan and know what works for your child, you can help them live an active life.

  • Help them stand and walk as much as possible. Being upright will keep your child's bones strong and their spine straight. Braces or standing walkers can make it easier for them to stand and get around.
  • Encourage them to eat right. There's no special diet for children with DMD, but healthy foods can prevent weight problems or help with constipation. Work with a dietitian to make sure your child eats the right balance of nutrients and calories each day. You may need to see a specialist if your child has trouble swallowing.
  • Promote physical activity. Exercise and stretches can keep your child's muscles and joints limber and help them feel better. A physical therapist can teach them how to exercise safely without overworking.
  • Find support. Other families living with DMD can be great resources for advice and understanding about life with the disease. Find a local support group or explore online discussion boards. It may also help you to talk about your feelings with a psychologist or counselor.

As your child gets older, their muscles will become weaker and they most likely won't be able to walk. Many boys with DMD will need a wheelchair by the time they are 12 years old to help them get around. 

Although some kids live only into their teens, the outlook for this condition is much better than it used to be. Today, young adults with DMD can go to college, have careers, marry, and start families.

Scientists are also testing new ways to treat the genes that cause DMD. These treatments might soon improve the outlook for even more for people with DMD.

Learning as much as you can about DMD, connecting to researchers, and keeping in touch with the wider DMD community can make a huge difference in navigating care, finances, and caring for your emotional well-being. 

There are several organizations, advocacy groups, and financial assistance programs built specifically for DMD families and those living with rare diseases.

The Muscular Dystrophy Association (MDA) offers monthly community support groups, care center resources, and one-on-one guidance from trained specialists. 

CureDuchenne has a one-to-one program that offers meetings with scientists, physical therapists, parents, fundraising teams, and family support resource coordinators focused solely on DMD.

The Duchenne Registry is a centralized patient database that links families, doctors, and researchers to help with research participation and care coordination. 

The EveryLife Foundation for Rare Diseases provides advocacy training, awareness campaigns, and community connections. 

NORD's RareCare Program offers financial help with medication costs, travel, and insurance premiums for rare disease patients through the National Organization for Rare Disorders. 

The Patient Advocate Foundation gives small grants and offers case management for families facing urgent financial needs. 

The PAN Foundation supports disease-specific grants covering copays, premiums, and travel expenses. 

Parent Project Muscular Dystrophy (PPMD) connects families through local "Connect" groups and virtual mentoring to match newly diagnosed people and their families with experienced caregivers. Finding others who know what life with DMD is like can help you feel less alone.

Ask your child's care team about hospital social workers or nonprofit case managers who can connect you to state and local services, travel aid, medical equipment programs, and respite care.

It's completely normal to feel fear, sadness, isolation, and uncertainty when you're caring for a child with DMD. Parents of children with rare diseases report significantly higher levels of psychological stress, anxiety, and depression, compared to other parents.

Sometimes, tending your own needs can fall down the priority list, but caregivers need care, too. Make a point to do things for your own mental health, such as:

Journal. This can help you see if you're feeling down or out of energy – signs that you need more support.

Get outside in nature. A short walk around your neighborhood with fresh air at least once a day is good for resetting your mood.

Ask for help. Practice reaching out to others who can offer meals, run errands, or simply be a listening ear. 

Eat nutritious foods that make you feel good. If you're already focused on your child's diet, make sure you're nourishing you, too.

Try professional support. A licensed counselor, therapist, or psychiatrist can address anxiety, depression, and help you name and process your feelings. 

Duchenne muscular dystrophy (DMD) is a rare genetic disease that causes muscles to weaken over time, affecting movement, breathing, and heart function. It mostly affects boys and usually appears in early childhood. While there's no cure, new treatments are helping children live longer and stay active for more years than ever before. If your child has DMD, organizations like the Muscular Dystrophy Association (MDA), Parent Project Muscular Dystrophy (PPMD), and CureDuchenne offer expert guidance, support groups, and family connections. Financial help is also available through NORD's RareCare, the Patient Advocate Foundation, and the PAN Foundation. Caring for a child with DMD can be emotionally demanding, so make time for your own well-being. Talk with a counselor, join a parent support group, and take small breaks when you can.

What is my child's life expectancy with DMD? 

With new advancements in treatments, DMD life expectancy is higher than ever, at a little over 31 years old. 

How is DMD treated? 

DMD doesn't have a cure, but treatments can slow the progression of muscle weakness and improve quality of life. These include steroids, gene therapy, heart care, physical therapy, respiratory therapy, nutritional support, and orthopedic therapies.

What causes DMD? 

DMD is caused by a mutation in the gene that makes dystrophin, a protein that keeps muscles strong and healthy. The mutation makes you have less dystrophin, and muscles get weak over time.

Can people with DMD live independently?

Movement restrictions and complications can make it harder to stay independent over time, but with adaptive devices and supportive care, it's possible to find many ways to live an independent, full life.