What is congenital muscular dystrophy?

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The symptoms of CMD can vary between individuals. Scientists have found at least 30 separate kinds of CMD. Each type may cause a unique set of symptoms.

However, some of the more common symptoms of CMD may include:

• low muscle tone in early infancy
• joint tightness
• breathing problems
• limited mobility
• eating difficulties

Infants born with CMD may appear floppy because of their low muscle tone. Toddlers may have difficulty holding their heads up or sitting on their own. Children with CMD may develop the ability to walk. However, they may not begin to walk until age 5 or later.

In CMD, genetic mutations can affect muscle development, and different mutations affect muscles in different ways.

The Muscular Dystrophy Association currently recognizes 33 different types of CMD. Each type involves a specific genetic mutation.

Some of the more common types of CMD include:

• Becker dystrophy
• Fukuyama dystrophy
• myotonic dystrophy
• Duchenne dystrophy

Scientists have found that Duchenne dystrophy is the most common type of CMD. Researchers estimate that it affects about 1 in 3,600 boys.

However, the most common type of CMD can depend on an individual’s location. In Japan, for example, Fukuyama muscular dystrophy is the most prevalent type of CMD.

Congenital muscular dystrophy is a genetic disease, meaning genetic changes or mutations cause CMD symptoms.

People with CMD inherit mutations from their parents. These mutations have a negative effect on a certain kind of protein known as a glycoprotein. Damage to these proteins leads to impaired muscle function.

In most cases, people with CMD inherit this disease in a recessive pattern. This means that they inherit one mutation from each of their parents.

A person can talk with a doctor to learn more about what causes CMD. Individuals with a family history of CMD may also be eligible for genetic screening.

The onset of CMD typically occurs at birth or in early infancy. Infants and children with CMD may develop a range of different symptoms. As infants, individuals with CMD may experience:

• breathing problems
• joint tightness
• spinal curvature
• swallowing difficulties

As they progress through childhood, these symptoms may grow to include:

• an increased risk of fractures
• developmental delays
• muscle weakness
• seizures
• vision problems
• heart conditions

The progression of CMD depends on many factors. These can range from age or secondary health conditions to CMD type. Symptoms may worsen over time and require more intensive care. Support needs for advanced CMD may include:

• mechanical ventilation to assist with breathing
• a feeding tube
• surgery
• intensive physical therapy

Each individual journey with CMD is unique. Some individuals may experience more advanced symptoms or require specialized care. To learn more about CMD progression, a person can consult a doctor. Only a medical professional can assess individual support needs.

Doctors conduct several different tests that can inform a CMD diagnosis. These typically begin with a physical exam. If a doctor suspects an infant has CMD, they can recommend additional tests. These may include:

• blood tests to check for atypical protein levels
• a brain MRI
• heart function tests such as an echocardiogram
• muscle biopsy
• genetic testing

Through genetic testing, a doctor can confirm a diagnosis of CMD and identify the specific CMD type. Determining what type of CMD an individual has can help doctors develop an effective treatment plan.

There is currently no treatment available that can cure CMD. However, a number of different treatments can help individuals with CMD manage their symptoms. These may include:

• physical therapy
• surgical intervention
• breathing support
• occupational therapy

Recent studies have also shed new light on gene therapy for CMD. This type of treatment works by changing an individual’s genetic material, which can address the genetic mutations that cause CMD.

Early studies have indicated that gene therapy can reduce CMD symptoms in certain cases. Future research may help expand the potential of this novel treatment.

CMD is a fairly rare condition, which some scientists believe affects about 1 in 5,000 people. In most cases, individuals with CMD receive a diagnosis in infancy or early childhood.

The rates of CMD may vary according to geographic location. Certain types of the disease are also more common than others in specific regions. A person can consult a local doctor to learn more about the prevalence of CMD in different areas.

Below are answers to common questions about CMD.

What is the life expectancy of a child with muscular dystrophy?

The life expectancy of a child with CMD can vary considerably. For instance, children with a type of CMD known as muscle-eye-brain disease generally live between 10 and 30 years. The average life expectancy for Duchenne muscular dystrophy is about 22 years.

What is the most common congenital muscular dystrophy?

Duchenne muscular dystrophy is the most common type of CMD, affecting about 1 in 3,600 boys. However, different types of CMD are more common in certain areas. In Japan, the most common type of CMD is Fukuyama muscular dystrophy.

Congenital muscular dystrophy (CMD) is an inherited disease that affects muscles throughout the body. Most people with CMD receive a diagnosis during their birth or infancy.

Individuals with CMD can experience a range of different symptoms, such as muscle weakness, joint problems, and breathing difficulties. The symptoms of CMD are progressive, which means they worsen over time.

Although there is no cure for CMD, researchers have developed different treatments for managing CMD symptoms. Novel treatments, such as gene therapy, can also help in certain cases.