Duchenne muscular dystrophy (DMD)): Cause, Symptoms & Treatment
Duchenne muscular dystrophy (DMD)
Duchenne muscular dystrophy (DMD) is a genetic disorder that primarily affects boys and is caused by a mutation in the gene that codes for dystrophin, a protein involved in maintaining the structure and function of muscle fibers. As a result of the mutation, boys with DMD have little or no dystrophin in their muscles, which leads to progressive muscle weakness and wasting.
Cause of Duchenne muscular dystrophy (DMD)
Duchenne muscular dystrophy (DMD) is caused by a mutation in the gene that codes for the protein dystrophin, which is essential for maintaining the structure and function of muscle fibers. This gene is located on the X chromosome, so DMD is an X-linked genetic disorder.
Since males only have one X chromosome, if they inherit a mutated copy of the dystrophin gene from their mother, they will develop DMD. Females have two X chromosomes, so they can inherit a mutated copy of the gene from one parent and a normal copy from the other. In this case, they are usually carriers of the disease and may have milder symptoms or no symptoms at all.
The dystrophin gene contains instructions for making a very large protein, and a wide range of different mutations can occur within the gene. The severity of DMD can vary depending on the specific mutation involved and how much dystrophin is produced. In general, mutations that result in little or no production of dystrophin lead to more severe symptoms.
Symptoms of Duchenne muscular dystrophy (DMD)
The symptoms of Duchenne muscular dystrophy (DMD) usually appear in early childhood and become more severe over time. The following are some of the most common symptoms of Duchenne muscular dystrophy (DMD) :
- Progressive muscle weakness: DMD causes progressive muscle weakness, particularly in the legs and pelvis, which can make it difficult for affected children to walk, run, or jump.
- Delayed motor milestones: Children with DMD may have delayed motor milestones, such as crawling and walking.
- Gait abnormalities: As the disease progresses, affected children may develop an abnormal gait, such as walking on their toes or with a waddling gait.
- Muscle wasting: DMD causes progressive muscle wasting, particularly in the lower extremities, which can lead to muscle deformities.
Fatigue: Children with DMD may experience fatigue or weakness after exertion.
- Breathing difficulties: DMD can affect the muscles used for breathing, which can lead to respiratory problems, such as shortness of breath, frequent lung infections, and sleep apnea.
- Cardiac problems: DMD can also affect the muscles of the heart, leading to cardiac problems such as cardiomyopathy.
- Learning difficulties: Some children with DMD may experience learning difficulties or cognitive impairment.
Treatment For Duchenne muscular dystrophy (DMD)
Currently, Duchenne muscular dystrophy (DMD) has no cure. However, there are several treatments that can help manage symptoms and improve the quality of life for affected individuals. These include:
- Steroid medications: Steroids such as prednisone or deflazacort can help slow the progression of muscle weakness and delay the loss of muscle function in some individuals with DMD.
- Physical therapy: Physical therapy can help improve muscle strength, flexibility, and range of motion, as well as prevent joint contractures.
- Respiratory support: As DMD progresses, individuals may develop breathing difficulties and require respiratory support, such as using a machine to help them breathe at night.
- Cardiac care: Regular monitoring of heart function and treatment of cardiac problems, such as heart failure or arrhythmias, is important for individuals with DMD.
- Assistive devices: Devices such as wheelchairs, braces, and standing frames can help individuals with DMD maintain mobility and independence.
- Gene therapy and other experimental treatments: Researchers are currently studying gene therapy and other experimental treatments for DMD, which may hold promise for slowing or even reversing the progression of the disease.
It’s important for individuals with DMD to receive comprehensive care from a team of healthcare providers, including a neurologist, cardiologist, respiratory therapist, physical therapist, and occupational therapist.