While there is still much that the scientific community does not fully understand about the causes and drivers of Duchenne muscular dystrophy (DMD), the typical disease progression is well-characterized. Muscle loss worsens over time, leading to mobility, breathing and heart problems.
Muscle weakness and mobility difficulties
DMD is a genetic disease that causes progressive muscle weakness. Muscle weakness can manifest in a number of ways, including having an abnormal gait and experiencing frequent falls.
Because DMD typically affects young boys who are at the stage of learning to walk, parents may notice differences in walking stability and confidence between children with DMD and their healthy peers.
Even if patients are on the best DMD therapies currently available, they still typically experience growing muscle weakness as time progresses. Eventually, muscle weakness may make it impossible for patients to move about independently. DMD is known to progress very quickly, and studies show that patients usually need a wheelchair by 10 years of age.
In addition, patients with DMD are at a higher risk of experiencing reduced bone mineral density, which increases the risk of fractures and adds to mobility challenges.
Unfortunately, a diagnosis of DMD means that boys are less likely to be able to participate in physical activities that are typical for their age, which can lead to a sense of social isolation.
Respiratory problems
Muscle weakness in DMD can cause a number of respiratory problems that require close monitoring. Doctors typically monitor respiratory function using a breathing test known as a spirometry, which allows them to track respiratory deterioration over time.
DMD is associated with a number of respiratory challenges, such as:
- Ineffective coughing
- Shallow breathing
- Lung collapse
- Increased risk of lung infection
Different patients are susceptible to different types of respiratory difficulties, and treatment will depend on an individual patient’s unique needs. Eventually, as respiratory muscles become progressively weaker most patients with DMD will need ventilatory support to help them breathe more effectively.
Read more about the prognosis of DMD
Cardiac concerns
The heart is one of the most important muscles of the body, and weakness of this vital muscle can cause a number of problems. The term that doctors use to describe cardiac problems due to muscle weakness is “cardiomyopathy,” with “cardio” referring to the heart and “myopathy” referring to muscle abnormalities.
DMD-associated cardiomyopathy can result in a number of vulnerabilities in the heart. Examples of heart problems may include:
- Cardiac fibrosis, which means scarring of the heart tissue
- Cardiac arrhythmias, or irregular heart rhythms
- Heart failure, meaning the heart is unable to pump blood at a level necessary for healthy function
Care teams typically use a mixture of cardiac imaging techniques to track the progression of heart problems in patients with DMD. When warranted, doctors will recommend treatment relevant to the cardiac abnormality present, such as prescribing medications that can reduce the symptoms of heart failure or an irregular heart rhythm.
Creating better care
Because DMD is typically diagnosed in boys at a young age, muscle weakness and other symptoms can create health issues that cause them to lag behind their peers. This is why DMD is typically managed in a multidisciplinary setting, which means that doctors from different departments collaborate on care, exchanging input and insights on how to give your child the best care possible.
While a diagnosis of DMD can be devastating, current therapies can alleviate many of the symptoms associated with the disease, or at least slow disease progression. Many patients with DMD now live into their 30s. Currently, clinical trials are being conducted in the hopes of developing better therapies for patients with DMD.
Sign up here to get the latest news, perspectives, and information about DMD sent directly to your inbox. Registration is free and only takes a minute.
