Duchenne muscular dystrophy (DMD) is a condition that causes skeletal and heart muscle weakness that quickly gets worse with time. Symptoms usually begin by the age of 6 years, and the condition mainly affects children assigned male at birth. There’s currently no cure, so treatment involves managing symptoms and improving quality of life.
Most cases of DMD are inherited as an X-linked recessive trait (passed on through the mother, who is a carrier), but approximately 30% of cases are due to new genetic changes (mutations) that happen randomly and aren’t inherited.
Duchenne muscular dystrophy mainly affects children assigned male at birth (AMAB), but children assigned female at birth (AFAB) who are carriers for DMD can sometimes have milder symptoms.
Symptoms of muscle weakness usually appear by the age of 2 years to 4 years, but sometimes, are noted as late as 6 years.
Duchenne muscular dystrophy affects about 1 in 3,600 male live-born infants. It’s the most common type of severe hereditary myopathies (disorders of skeletal muscles).
Yes, Duchenne muscular dystrophy is ultimately fatal. Most people with the condition die from lung or heart issues caused by it.
Symptoms of Duchenne muscular dystrophy (DMD) most often appear between the ages of 2 and 4 years, though they can begin as early as infancy or be noticed later in childhood.
DMD causes muscle weakness that worsens over time, so common symptoms include:
Other common symptoms of DMD include:
About 2.5% to 20% of children AFAB who are carriers of DMD may have symptoms that are usually milder.
Duchenne muscular dystrophy (DMD) is caused by a change (mutation) in the gene that gives instructions for a protein called dystrophin. Dystrophin is a critical part of the dystrophin-glycoprotein complex (DGC), which plays an important role as a structural unit of muscle.
In DMD, both dystrophin and DGC proteins are missing, which ultimately leads to the death (necrosis) of muscle cells. People with DMD have less than 5% of the normal quantity of dystrophin needed for healthy muscles.
As people with DMD age, their muscles can’t replace the dead cells with new ones, and connective and adipose (fat) tissue gradually replaces muscle fibers.
Duchenne muscular dystrophy has X-linked recessive inheritance, but about 30% of cases happen spontaneously without a family history of the condition.
X-linked means the gene responsible for DMD is located on the X chromosome, one of two sex chromosomes. People AMAB have an X and Y chromosome, and people AFAB have two X chromosomes.
Genes, like chromosomes, usually come in pairs. Recessive means that when there are two copies of the responsible gene, both copies must have a disease-causing change (pathogenic variant or mutation) for a person to have the condition. Since people AMAB only have one X chromosome, if that chromosome has the genetic variant that causes DMD, they’ll have DMD.
If your child is experiencing symptoms of Duchenne muscular dystrophy (DMD), your child’s healthcare provider will likely perform a physical exam, neurological exam and muscle exam. They’ll ask detailed questions about your child’s symptoms and medical history.
If your child’s provider suspects that your child may have DMD, they’ll likely order the following tests:
There’s currently no cure for Duchene muscular dystrophy (DMD), so the main goal of treatment is to manage symptoms and improve quality of life.
Supportive therapies for DMD include:
Other supportive therapies for DMD include:
With improvement in supportive care over the years, the life expectancy of DMD has significantly improved over the past few decades.
There are many new drugs currently undergoing clinical testing that show promise in treating DMD. Some newer treatments that employ “exon skipping” (patching over a missing or mutated part of the dystrophin gene) have recently received FDA (Food and Drug Administration) approval. These treatments are applicable only to a minority of cases that have very specific mutations. Although these treatments increase dystrophin protein amount in muscle, meaningful gain in strength and physical function has not yet been shown.
As Duchenne muscular dystrophy (DMD) is an inherited condition, there’s nothing you can do to prevent it. About a third of cases happen randomly without a family history of the condition.
If you’re concerned about the risk of passing on DMD or other genetic conditions before trying to have a biological child, talk to your healthcare provider about genetic counseling. In some situations, prenatal testing may be able to diagnose DMD in early pregnancy.
The prognosis is often poor for people with Duchenne muscular dystrophy (DMD). It leads to progressively worsening disability, and most children with DMD need to use a wheelchair by the age of 12. DMD ultimately results in death at an early age.
People with Duchene muscular dystrophy often die from the condition by the age of 25 years. However, advances in supportive care have resulted in many people living longer.
Death often occurs as a result of respiratory (breathing) or heart complications. Other causes of death include pneumonia, aspiration (breathing in a foreign object, such as food) or airway obstruction.
If you’re taking care of someone with Duchenne muscular dystrophy (DMD), it’s important to advocate for them to ensure they get the best medical care and access to therapy that can help them have the best quality of life.
You and your family may also want to consider joining a support group to meet others who can relate to your experiences.
If your child has been diagnosed with Duchenne muscular dystrophy, they’ll need to see their team of healthcare providers regularly to receive treatment and monitor symptoms.
A note from Cleveland Clinic
Understanding your child’s Duchenne muscular dystrophy (DMD) diagnosis can be overwhelming. Your healthcare team will offer a robust management plan that’s unique to your child’s symptoms. It’s important to make sure your child is getting the support they need and to stay attentive to their health. Know that their healthcare team will be there to support them and your family.
Last reviewed by a Cleveland Clinic medical professional on 07/25/2022.
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