Introduction
The hereditary disorder Duchenne muscular dystrophy (DMD), which predominantly affects the muscles and causes muscle weakness and eventually loss of muscle function, is severe and progressive. It is one of the most prevalent and disabling types of muscular dystrophy, generally detected in young boys. DMD is named for the 19th-century French neurologist Guillaume Duchenne, who initially identified the disorder.
Mutations in the DMD gene, which is found on the X chromosome and encodes the protein dystrophin, which is crucial for the integrity of muscle cells, are the root cause of this genetic condition. Muscle fibers are more easily injured during muscle contraction due to dystrophin deficiency or malfunction, which sets off a chain reaction of muscle fiber degeneration and regeneration.
Early childhood is typically when DMD symptoms first emerge, with affected children exhibiting delayed motor development and muscle weakness, especially in the legs and pelvis. People with DMD may develop trouble walking as the condition worsens, experience frequent falls, and finally require a wheelchair. In later stages of the disease, muscle weakening also affects the respiratory and cardiac muscles, resulting in breathing issues and heart issues.
The quality of life for persons with Duchenne muscular dystrophy and their family is significantly impacted by the condition. Even though there is presently no cure, ongoing research is concentrated on creating treatments to control symptoms, reduce the disease’s course, and possibly give people with DMD hope for a brighter future.
Causes
Genetic abnormalities that disrupt the synthesis of the essential muscle protein dystrophin are the main cause of Duchenne muscular dystrophy (DMD). The causes of DMD are explained in more depth below:
Genetic Mutation: Mutations in the DMD gene, which is found on the X chromosome, are the primary cause of DMD. Dystrophin, a protein necessary for preserving the structural integrity of muscle fibers, is encoded by this gene. Dystrophin is absent or inactive as a result of mutations in the DMD gene.
Inheritance Pattern: DMD is passed down through an X-linked recessive inheritance pattern. This indicates that carrier moms frequently convey the genetic mutation that causes DMD to their male sons. Males are more frequently affected by DMD since they have one X and one Y chromosome (XY). Females with two X chromosomes (XX) can carry the mutation without ever experiencing any symptoms.
Spontaneous Mutations: In a few instances, DMD mutations can happen naturally during the formation of the egg or sperm, resulting in affected people who have no known family members with the condition. These people are regarded as having “de novo” mutations.
Carrier Status: Female carriers have one copy of the DMD gene that is healthy and one copy that is mutant. Despite the fact that they usually do not show any symptoms, they can carry the mutation to their progeny. There is a 50% probability that sons of carriers may inherit the mutant gene and acquire DMD.
Genetic diversity: The kind and position of DMD mutations can vary within the DMD gene, resulting in variances in the disease’s severity and course among those who are affected.
SYMPTOMS
A variety of symptoms that are characteristic of Duchenne muscular dystrophy (DMD) often appear in early childhood, frequently between the ages of 2 and 6. Because of the deterioration of muscle fibers, these symptoms are progressive and get worse over time. Here are the key symptoms associated with DMD:
Muscle Weakness: One of the earliest and most noticeable symptoms is muscle weakness. Usually, it starts in the lower body, affecting the pelvis and legs, then progressively moves up to the upper body.
Walking Difficulties: Children with DMD frequently display delayed motor development and have trouble walking. They might walk with a waddling gait and trip up regularly.
Frequent Falls: As the illness worsens, muscular wasting and instability lead to more often occurring falls, making mobility more difficult.
Progressive Muscle Wasting: As a result of the replacement of muscle tissue over time by fat and connective tissue, progressive muscle wasting occurs. Loss of muscular mass is the outcome, especially in the calves.
Pseudohypertrophy of the calf muscles: Ironically, as muscles deteriorate, the calf muscles may appear bigger or “pseudohypertrophic” because of the buildup of fat and connective tissue.
Respiratory Difficulties: Muscle weakness affects the respiratory muscles, which results in breathing problems. Many DMD sufferers eventually need breathing assistance, like a ventilator.
Heart Problems: Cardiomyopathy and other cardiac problems can result from DMD’s impact on the heart muscles. It’s crucial to have regular heart monitoring.
Joint Contractures: Muscle wasting can cause joint contractures, which restrict joint flexibility and movement.
Loss of Ambulation: Most people with DMD stop being able to walk on their own by the time they are in their early teens, usually between the ages of 10 and 12.
Scoliosis: People with DMD frequently experience abnormal spinal curvature (scoliosis), which may call for bracing or surgical treatment.
Cognitive Function: Although they are not always present and range in severity, cognitive and behavioral difficulties can occur in some people with DMD.
Fatigue: Exercise and muscle weakness can cause greater fatigue, which can interfere with day-to-day tasks.
treatment
Due to its hereditary basis, Duchenne muscular dystrophy (DMD) has no known cure. To manage symptoms, halt the spread of the illness, and enhance the quality of life for people with DMD, many therapeutic modalities and therapies are employed. Following are some crucial elements of DMD treatment:
Corticosteroids: These drugs, including prednisone or deflazacort, are frequently used to help halt muscle aging, postpone losing one’s ability to walk, and increase muscle strength. Additionally, they can support respiratory function.
Physical Therapy: Programs for physical therapy are made to keep muscles flexible, mobile, and generally mobile. These activities can lower the risk of falls and postpone joint contractures.
Respiratory treatment: As DMD affects the respiratory muscles, people frequently need breathing support. This may involve using a tracheostomy or BiPAP during the night for continuous mechanical ventilation.
Cardiac Care: To treat heart-related problems that can arise in people with DMD, regular cardiac monitoring and medicines are crucial.
Orthopedic interventions: In order to treat joint contractures and scoliosis, bracing and surgery may be required
Assisted Technology: As ambulation becomes more challenging, assistive devices like wheelchairs and scooters can help people preserve their independence and quality of life.
Medication and Therapies: New medications and therapies are being created and studied, including gene therapy techniques and exon-skipping medications like Eteplirsen. Targeting the underlying genetic etiology of DMD may be possible with these.
Psychosocial Assistance: Support on the Psychosocial Spectrum: Having DMD can be emotionally taxing. People with the condition and their families can manage the emotional and psychological effects of the illness with the aid of psychosocial support, therapy, and support groups.
It is crucial to remember that a team of specialists, including neurologists, pulmonologists, cardiologists, physical therapists, and genetic counselors, should be included in the multidisciplinary management of DMD. Future improvements in DMD treatment and therapy are possible because of scientific advancements and ongoing clinical studies. For the most recent details about DMD therapies and management options, please speak with a healthcare expert.
CONCLUSION
A severe genetic condition known as Duchenne muscular dystrophy (DMD) causes gradual muscle weakening. It is brought on by changes to the dystrophin protein induced by mutations in the DMD gene. Walking difficulties, muscle atrophy, and respiratory and heart issues are among the symptoms. Although there is no cure, the disease can be treated with corticosteroids, physical therapy, and respiratory assistance. Hope can be found in novel therapeutics like gene-based therapy. For both individuals and families, psychosocial assistance is essential. The results of ongoing research could improve the situation for those with DMD. For the most recent information on management and treatments, speaking with healthcare specialists is crucial.
