Duchenne muscular dystrophy is a genetic disease characterized by severe muscle degeneration that affects mainly males. The onset of this disease begins at the age of four and deterioration progresses very quickly. When there is muscle loss the affected individual may have trouble performing actions like walking or standing and most develop difficulty walking by the age of twelve.
It is an X linked recessive disease. Male children born having this mutated gene are affected because they possess only one X chromosome whereas for a female to be affected; because it’s recessive should carry the mutation in both the x chromosome. In most cases females are only carriers which means only one of their x chromosomes is affected and they have normal function.
Dystrophin is a protein that attaches the cytoskeleton of the muscles to the basal lamina, through a complex of protein, which in turn gives the cell its integrity. With the absence of dystrophin this attachment is not maintained and calcium can start to permeate the cell membrane. Because there is a change in the ion, certain pathways are stimulated which leads to the water entering into the mitochondria leading to the bursting of the organelle, this usually is followed by a cascade of dystrophic changes which are mediated with the generation of reactive oxygen species.
Signs and symptoms
This disease begins with the involvement of voluntary muscles first, especially the hips, legs and pelvis area and go on to involve the upper limb, symptoms may appear before the age of 5. The motor muscles are the ones that are usually affected, the child finds it difficult to walk or run, this is associated with the Achilles tendon shortening.
A child may experience frequent falls and the ability to walk slowly gets worse with the child not having the ability to walk by age 13. One of the main signs of this disease is called the Gowers sign this is when the child finds it difficult to stand up from a sitting or lying position. Skeletal abnormalities like scoliosis can also be seen.
Can be detected with genetic studies when performed during pregnancy and creatinine kinase levels are usually high in this case and EMG shows muscle weakness. When DNA testing does not reveal mutation muscle biopsy can be performed
There is no specific treatment and management is aimed at symptomatic control. Physical therapy is very helpful. This is aimed to help patients improve their motor functions; for example, incorporating useful exercises recommended by a physiotherapist Geelong medical centre.
Medical therapy includes administering steroids mainly prednisolone. Other equipment’s like wheelchairs are used to aid with mobility
This disease involves muscles that initially affect voluntary muscles but may later involve the cardiac and respiratory muscles leading to cardiac and respiratory failure. The average life expectancy of someone with Duchenne muscular dystrophy is around 25-26 but with proper management, this can be extended to 30 years and starting the management early has shown to provide longevity in people with this disease.