Duchenne muscular dystrophy (DMD) is an x-linked pathology of the muscular system that occurs predominantly in boys. This progressive degenerative condition that results in severe motor disability occurs in roughly 1 in 5,000 births. Caused by mutations in the dystrophin gene, DMD results in the eventual loss of motor function, and, in the absence of a cure, available treatments can only slow muscle degradation and increase life expectancy.
DMD was first diagnosed and described in 1857. It is named after Duchenne de Bologne “based on his report of a young boy suffering from ‘congenital hypertrophic paraplegia’” (Kah, 2018, p. 3). The etiology of DMD is linked to mutations in the dystrophin gene, which causes the excess of calcium ions in muscles and the gradual degradation of muscle fiber with a build-up of fat and scar tissue. It results in the eventual loss of motor function and, ultimately, cardiac or respiratory failure.
DMD usually manifests when a patient is about two or three years old. It manifests as weakness and muscle wasting, first in the proximal limb muscles and then in more distal muscles (Tsuda, 2018). By early adolescence, the build-up of scar tissue and fat usually results in an intractable motor disability for most patients (Tsuda, 2018). The average life expectancy for those affected by MD is around 25 years.
While no cure is found up to date, therapeutic approaches for DMD are in development. Stem cell therapy is used to improve muscle quality, and gene therapy seeks ways to deliver functional dystrophin genes to the affected organism (Dongsheng et al., 2021). Steroids, as well as other compounds to improve muscle mass, are also used or currently under development to address the symptoms of DMD (Dongsheng et al., 2021). With sufficient care, the patient’s life expectancy may be extended to 40 years.
To summarize, DMD is a severe degenerative pathology of the muscular system caused by mutations in the dystrophin gene. It leads to a gradual replacement of muscle fiber with scar tissue and fat, resulting in the loss of motor functions and, eventually, cardiac arrest or respiratory failure. A cure is not yet known, but several therapeutic approaches exist to address its symptoms and alleviate muscle degradation.
References
Dongsheng, D., Goemans, N., Takeda, S., Mercury, E., & Aartsma-Rus, A. (2021). Duchenne muscular dystrophy. Nature Reviews Disease Primers, 7, article number 13. Web.
Mah, J, K. (2018). An overview of recent therapeutics advances for Duchenne muscular dystrophy. In C. Bernardini (Ed.), Duchenne Muscular Dystrophy: Methods and Protocols (pp. 3-18). New York, NY: Humana Press.
Tsuda, T. (2018). Clinical manifestations and overall management strategies for Duchenne muscular dystrophy. In C. Bernardini (Ed.), Duchenne Muscular Dystrophy: Methods and Protocols (pp. 19-30). New York, NY: Humana Press.