Duchenne Muscular Dystrophy is a rare genetic disorder that gradually makes muscles weak. It is a progressive disorder that leads to muscle wasting. It results due to a genetic mutation in a muscle protein called dystrophin. Dystrophin helps the muscles function correctly; its absence will make muscles weak and damaged. Duchenne Muscular Dystrophy primarily affects males, but sometimes it occurs in females too.
Duchenne Muscular Dystrophy is the most common form of severe muscular disorder. It occurs in 1 in 3600 male births. Duchenne Muscular Dystrophy is a fatal hereditary disease. Death mainly occurs due to complications of the lungs and heart. The disease diagnosis is most commonly made between 2 to 4 years of age. Read this article to understand the causes, symptoms, and treatment of Duchenne Muscular Dystrophy (G_enetic and Rare Diseases Information Center_, n.d).
What Causes Duchenne Muscular Dystrophy?
A mutation in the gene that codes for dystrophin and dystrophin-glycoprotein complex is present in Duchenne Muscular Dystrophy. People with DMD have less than 5 percent of normal dystrophin in their bodies. Without these two proteins, muscle cells cannot survive and start to die. With the increasing age of DMD patients, muscular cells' capacity to survive diminishes, and necrosis begins. The standard muscle fibers are converted into connective tissue and fat.
Duchenne Muscular Dystrophy has X linked recessive pattern for inheritance, but one-third of the people get DMD without any family history. Both X chromosomes must get the mutation to cause disease. Males have only one X chromosome, while females have two X chromosomes, thats why the disease is more common in males (MedlinePlus Medical Encyclopedia, n.d).
What are the Symptoms of Duchenne Muscular Dystrophy?
The symptoms of DMD can be visible as early as infancy or be noticed in late childhood. The typical age for appearing symptoms is between 2 to 4 years. The most common symptom of Duchenne Muscular Dystrophy is a progressive muscular weakness that starts in the legs and gradually spreads in the whole body. It is less likely to occur in the arms and neck (Nehgri et al., 2019). Other symptoms of DMD are as follows:
· Increase in the size of calf muscles (hypertrophy)
· Difficulty in walking, which gets worse with time
· Inability to climb up stairs
· Walking of toe
· Tiredness in the whole body
· Shortness of breath
· Abnormalities in cognition and learning
· Scoliosis
· Have an unsteady or waddling gait
· Behavioral disorders are present
How is the Diagnosis of Duchenne Muscular Dystrophy Made?
First thing first, take the history and then perform a physical examination to make the diagnosis of Duchenne Muscular Dystrophy. Neurological and muscular examinations are essential for diagnosing DMD (Johns Hopkins Medicine, 2021). Some tests can help in the diagnosis; these are the following:
· Creatinine kinase blood test: The damaged muscles are tended to release creatinine kinase, so elevated levels indicate the presence of Duchenne Muscular Dystrophy. The levels are 10 to 20 times more than the normal levels. The peak levels can be recorded between the age of 2 to 4 years.
· Genetic blood test: It is done to find the presence of dystrophin in genetic material. The complete absence or less presence indicated Duchenne Muscular Dystrophy.
· Muscular Biopsy: In this method, a small portion of muscular tissue is extracted and examined under the microscope to see the signs of DMD.
· Electrocardiogram: Duchenne Muscular Dystrophy always has adverse effects on the heart. Hence, an electrocardiogram helps determine the specific effects of DMD on the heart, which can aid in the diagnosis.
What is the Treatment of Duchenne Muscular Dystrophy?
There is no cure for Duchenne Muscular Dystrophy, but there are treatment options that can relieve the symptoms of the disease and prevent its complications. Etiplirsen is a medication that has been approved for the treatment of muscular dystrophy related to DMD. This medication tends to increase dystrophin production, enhancing muscle functionality ( De Los Angeles Beytía et al., 2012). Moreover, corticosteroids also seem helpful in retaining muscle strength and enabling patients to walk. Steroids also slow down muscle damage, so patients taking steroids can walk a few years more than others (Pichavant et al., 2011).
Treatment and management of complications are also necessary. As DMD causes heart and lung problems, one should visit a pulmonologist and cardiologist for proper advice and treatment. Cashmere is a medicine used in patients with a mutation of exon 45 skippings. It helps in increasing the production of dystrophin. Some patients with DMD also require surgery to fix spine abnormalities and heart problems (Centers for Disease Control and Prevention, 2016)
Conclusion
Understanding Duchenne Muscular Dystrophy (DMD) is essential for medical professionals and the broader community. This degenerative genetic disorder, primarily affecting young boys, brings a range of challenges that extend beyond the physical realm. By delving into the complex genetic and molecular mechanisms that underlie DMD, researchers and clinicians have made significant strides in developing potential treatments and interventions to improve the quality of life for those affected.
References
Duchenne muscular dystrophy - About the Disease - G_enetic and Rare Diseases Information Center_. (n.d.). https://rarediseases.info.nih.gov/diseases/6291/duchenne-muscular-dystrophy
Duchenne muscular dystrophy: MedlinePlus Medical Encyclopedia. (n.d.). https://medlineplus.gov/ency/article/000705.htm
Nhgri. (2019). About Duchenne Muscular Dystrophy. Genome.gov. https://www.genome.gov/Genetic-Disorders/Duchenne-Muscular-Dystrophy
Duchenne Muscular Dystrophy. (2021, August 8). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/duchenne-muscular-dystrophy
De Los Angeles Beytía, M. (2012, May 1). Drug treatment of Duchenne muscular dystrophy: available evidence and perspectives. PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440798/
Pichavant, C., Aartsma-Rus, A., Clemens, P. R., Davies, K. J., Dickson, G., Takeda, S., Wilton, S. D., Wolff, J. A., Wooddell, C. I., Xiao, X., & Tremblay, J. P. (2011). Current status of pharmaceutical and genetic therapeutic approaches to treat DMD. Molecular Therapy, 19(5), 830–840. https://doi.org/10.1038/mt.2011.59
Duchenne/Becker Treatment and Care | Muscular Dystrophy | NCBDDD | CDC. (2016, July 19). Centers for Disease Control and Prevention. https://www.cdc.gov/ncbddd/musculardystrophy/treatments.html