Duchenne muscular dystrophy (DMD) is a severe type of muscular dystrophy, a genetic disorder characterised by progressive muscle degeneration and weakness. It primarily affects boys and is one of the most common and devastating forms of muscular dystrophy. DMD is caused by mutations in the DMD gene, which encodes the protein dystrophin. Dystrophin is essential for maintaining muscle cell structure and function. Unfortunately, there is no cure.

Symptoms and Progression

The symptoms of DMD usually appear in early childhood, often between the ages of 2 and 5. Early signs may include:

• Delayed walking or difficulty with motor skills
• Frequent falls and difficulty getting up from a sitting or lying position
• Enlarged calf muscles (pseudohypertrophy)
• Difficulty running, jumping, and climbing stairs

As the disease progresses, muscle weakness and wasting become more pronounced, affecting the muscles of the hips, pelvic area, thighs, and shoulders first. Eventually, the muscle weakness spreads to the arms, legs, and trunk. By adolescence, many individuals with DMD require the use of a wheelchair.

In the later stages of DMD, muscle weakness affects the respiratory and cardiac muscles, leading to serious complications. Historically individuals with DMD did not survive beyond their 20s or 30s, although advances in medical care have extended life expectancy for some.

Cognitive Impact

While DMD primarily affects muscles, it can also impact cognitive function. Approximately one-third of boys with DMD experience some form of cognitive impairment, which can manifest in various ways, including:

• Learning Disabilities: Difficulties with reading, writing, and arithmetic.
• Attention Deficits: Problems with concentration and staying focused.
• Memory Issues: Challenges with short-term and working memory.
• Executive Functioning: Difficulties with planning, organizing, and problem-solving.
• Speech and Language: Delays in speech development and difficulties with language comprehension and expression.

It’s important to note that cognitive impairments in DMD vary widely; some boys may have mild difficulties, while others may experience more significant challenges. These cognitive issues are believed to be linked to the lack of dystrophin in the brain, which plays a role in normal brain function.

Causes and Genetics

DMD is an X-linked recessive disorder, which means the mutated gene is located on the X chromosome. Because boys have only one X chromosome (inherited from their mother), they are more likely to be affected by X-linked disorders like DMD. Girls have two X chromosomes, so even if one X chromosome carries the mutation, the other typically provides a functional copy of the gene, which usually prevents the development of symptoms.

Approximately one-third of DMD cases result from new mutations in the gene and occur in families with no prior history of the condition.

Research and Hope for the Future

Research into DMD is ongoing, with efforts focused on finding more effective treatments and ultimately a cure. Promising areas of research include:

• Gene Therapy: Techniques aimed at delivering a functional copy of the dystrophin gene to muscle cells.
• Exon Skipping: A strategy to skip over faulty parts of the gene to produce a partially functional dystrophin protein.
• Stem Cell Therapy: Investigating the use of stem cells to repair and regenerate damaged muscle tissue.

At Keeping Independence Together (KIT), we are dedicated to supporting boys with DMD and their families in the Dorset area by providing the necessary technology and resources to promote independence. Your support helps us make a difference in their lives and brings us closer to a future where Duchenne muscular dystrophy is no longer a life-limiting condition.