Duchenne Muscular Dystrophy
Late Pandurang Patil Nursing College, Akola.
*Corresponding Author E-mail: apbhoyar5@gmail.com
Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact. DMD is one of four conditions known as dystrophinopathies. DMD symptom onset is in early childhood, usually between ages 2 and 3. The daughters each have a 50% chance of being carriers. Very rarely, a female can be affected by the disease. Duchenne muscular dystrophy occurs in about 1 out of every 3600 male infants. The disease primarily affects boys, but in rare cases it can affect girls. Duchenne muscular dystrophy is a form of muscular dystrophy. The main sign of muscular dystrophy is progressive muscle weakness. Specific signs and symptoms begin at different ages and in different muscle groups. No cure for DMD is known, and an ongoing medical need has been recognized by regulatory authorities. Gene therapy has shown some success. Complications includes osteoporosis, nutritional problems, cardiac complication such as cardiomyopathy, chest and breathing complication. This condition can be improved when detected as early as possible.
KEYWORDS: Dystrophin, Children, Parents, Muscular dystrophy.
Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact. DMD is one of four conditions known as dystrophinopathies. The other three diseases that belong to this group are Becker Muscular dystrophy (BMD, a mild form of DMD); an intermediate clinical presentation between DMD and BMD; and DMD- associated dilated cardiomyopathy (heart-disease) with little or no clinical skeletal, or voluntary, muscle disease.1 DMD symptom onset is in early childhood, usually between ages 2 and 3. The disease primarily affects boys, but in rare cases it can affect girls1 In Europe and North America, the prevalence of DMD is approximately 6 per 100,000 individuals.1
Duchenne muscular dystrophy:
The best-known form of muscular dystrophy, due to mutation in a gene on the X chromosome that prevents the production of dystrophin, a normal protein in muscle.2
Duchenne muscular dystrophy is a form of muscular dystrophy. It worsens quickly. Other muscular dystrophies (including Becker muscular dystrophy) get worse much more slowly. Duchenne muscular dystrophy is caused by a defective gene for dystrophin (a protein in the muscles). However, it often occurs in people without a known family history of the condition. The condition most often affects boys due to the way the disease is inherited. The sons of women who are carriers of the disease (women with a defective gene, but no symptoms themselves) each have a 50% chance of having the disease. The daughters each have a 50% chance of being carriers. Very rarely, a female can be affected by the disease. Duchenne muscular dystrophy occurs in about 1 out of every 3600 male infants. Because this is an inherited disorder, risks include a family history of Duchenne muscular dystrophy. 3
The main sign of muscular dystrophy is progressive muscle weakness. Specific signs and symptoms begin at different ages and in different muscle groups, depending on the type of muscular dystrophy.
Duchenne type muscular dystrophy:
This is the most common form. Although girls can be carriers and mildly affected, it's much more common in boys. Signs and symptoms, which typically appear in early childhood, might include Frequent falls, Difficulty rising from a lying or sitting position, Trouble running and jumping, Waddling gait, Walking on the toes, Large calf muscles, Muscle pain and stiffness, Learning disabilities, Delayed growth. 4
Your doctor is likely to start with a medical history and physical examination. After that, your doctor might recommend:
· Enzyme tests. Damaged muscles release enzymes, such as creatine kinase (CK), into your blood. In a person who hasn't had a traumatic injury, high blood levels of CK suggest a muscle disease.
· Genetic testing. Blood samples can be examined for mutations in some of the genes that cause types of muscular dystrophy.
· Muscle biopsy. A small piece of muscle can be removed through an incision or with a hollow needle. Analysis of the tissue sample can distinguish muscular dystrophies from other muscle diseases.
· Heart-monitoring tests (electrocardiography and echocardiogram). These tests are used to check heart function, especially in people diagnosed with myotonic muscular dystrophy.
· Lung-monitoring tests. These tests are used to check lung function.
· Electromyography. An electrode needle is inserted into the muscle to be tested. Electrical activity is measured as you relax and as you gently tighten the muscle. Changes in the pattern of electrical activity can confirm a muscle disease. 5
No cure for DMD is known, and an ongoing medical need has been recognized by regulatory authorities. Gene therapy has shown some success. 6 Treatment is generally aimed at controlling the onset of symptoms to maximize the quality of life which can be measured using specific questionnaires, 7 and include:
· Corticosteroids such as prednisolone and deflazacort lead to short-term improvements in muscle strength and function up to 2 years. Corticosteroids have also been reported to help prolong walking, though the evidence for this is not robust. 8
· Randomised control trials have shown that β2 agonists increase muscle strength, but do not modify disease progression. Follow-up time for most RCTs on β2 agonists is only around 12 months, hence results cannot be extrapolated beyond that time frame.
· Mild, nonjarring physical activity such as swimming is encouraged. Inactivity (such as bed rest) can worsen the muscle disease.
· Physical therapy is helpful to maintain muscle strength, flexibility, and function.
· Orthopedic appliances (such as braces and wheelchairs) may improve mobility and the ability for self-care. Form-fitting removable leg braces that hold the ankle in place during sleep can defer the onset of contractures.
· Appropriate respiratory support as the disease progresses is important.
· Cardiac problems may require a pacemaker.
Physical therapists are concerned with enabling patients to reach their maximum physical potential. Their aim is to:
· Minimize the development of contractures and deformity by developing a programme of stretches and exercises where appropriate
· Anticipate and minimize other secondary complications of a physical nature by recommending bracing and durable medical equipment
· Monitor respiratory function and advise on techniques to assist with breathing exercises and methods of clearing secretions.9
Anaesthetics- People with DMD need extra care if they have a general anaesthetic. Certain anaesthetic medicines can cause a harmful reaction for people who have DMD. Also, extra care for the chest and breathing is needed. It is important to have a pre-operative assessment and a senior anaesthetist providing anaesthetic care.
Osteoporosis - People with DMD may develop osteoporosis. This is due to lack of mobility and also to steroid treatment. It is important to prevent osteoporosis as far as possible. A good intake of vitamin D and calcium can help. Sometimes a blood test to check vitamin D levels is advised, and vitamin D supplements may be offered
Joint and spinal complication- Muscle weakness can result in joint contractures. In DMD, it is often the ankle joint and Achilles' tendon which become tight. This can be treated either using orthotic devices or by surgical release of the tendon. Scoliosis can occur due to muscle weakness. Usually, this happens at the beginning of the second decade of life, after the patient has lost ambulation. Scoliosis can cause discomfort and is not helpful for posture and breathing. Treatments which can help are a spinal brace or surgery to the spine. Surgery has been shown to improve function and quality of life. Surgery should be done while the patient still has sufficient lung function and before cardiomyopathy becomes a major risk factor when putting the patient under anaesthesia.
Nutrition and digestion- Some children with DMD are prone to being overweight, especially if taking steroid treatment. Teenagers and adults with DMD may be underweight, due to loss of muscle bulk. Dietary advice can be helpful in these situations. Constipation can be a symptom for anyone who is not mobile. This can be treated with laxatives and a high fibre diet. In the later stages of DMD (as a young adult and older), people with DMD may have difficulty with chewing and swallowing food. They may need careful assessment and nutritional advice or supplements. If the problem is severe, then a gastrostomy may be needed.
Chest and Breathing Complication - During the teenage years, the breathing muscles weaken, causing shallow breathing and a less effective cough mechanism which can lead to chest infections. All individuals with DMD will present with restrictive lung disease. Clearance techniques and non-invasive ventilation may help. As the breathing muscles get weaker, oxygen levels in the blood may be reduced, more so while sleeping. Because this develops gradually, the symptoms may not be obvious. Possible symptoms are tiredness, irritability, morning headaches, night time waking and vivid dreams.
Cardiac complication - Teenagers and adults with DMD may develop cardiomyopathy. Cardiomyopathy generally develops around the age of 10 and by the age of 18 all individuals with DMD will present with cardiomyopathy . In dilated cardiomyopathy, it becomes difficult for the heart to pump blood to the body because the chambers have become enlarged and the heart wall has thinned . With DMD, the cardiomyopathy does not usually cause much in the way of symptoms. Possible symptoms are tiredness, leg swelling, shortness of breath or an irregular heartbeat. Cardiomyopathy can be helped by medication which seems to work best if started at an early stage before symptoms are noticed. So people with DMD are usually offered regular heart check-ups, starting from early childhood. The check-ups usually
involve an ECG.10
Duchenne muscular dystrophy is a rare progressive disease which eventually affects all voluntary muscles and involves the heart and breathing muscles in later stages. Life expectancy is estimated to be around 25- 26,but this varies. With excellent medical care males often live into their 30s. David Hatch of Paris, Maine may be the oldest person in the world with the disease; he is 58. The most common direct cause of death in people with DMD is respiratory failure. Complications from treatment, such as mechanical ventilation and tracheotomy procedures, are also a concern.11
CONCLUSION:
Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact. DMD symptom onset is in early childhood, usually between ages 2 and 3. The disease primarily affects boys, but in rare cases it can affect girls. Symptomatic treatment is available if we detect this disease at early stages. We can prevent this disease condition by doing regular checkups and early detection of this disease and maintaining proper protein diet.
1. https://www.mda.org/disease/duchenne-muscular-dystrophy
2. https://www.medicinenet.com/duchenne_muscular_dystrophy/defi nition.htm
3. https://medlineplus.gov/ency/article/000705.htm
4. https://www.mayoclinic.org/diseases-conditions/muscular- dystrophy/symptoms-causes/syc-20375388
5. https://www.mayoclinic.org/diseases-conditions/muscular- dystrophy/diagnosis-treatment/drc-20375394
6. https://www.pfizer.com/news/press-release/press-release- detail/pfizers-new-phase-1b-results-gene-therapy-ambulatory-boys
7. Dany A, Barbe C, Rapin A, Réveillère C, Hardouin JB, Morrone I, et al. (November 2015). "Construction of a Quality of Life Questionnaire for slowly progressive neuromuscular disease". Quality of Life Research. 24 (11): 2615–23. doi:10.1007/s11136- 015-1013-8. PMID 26141500. S2CID 25834947
8. Matthews E, Brassington R, Kuntzer T, Jichi F, Manzur AY (May 2016). "Corticosteroids for the treatment of Duchenne muscular dystrophy". The Cochrane Database of Systematic Reviews. 5(5): CD003725. doi:10.1002/14651858.CD003725.pub4. PMID 27149418
9. https://en.wikipedia.org/wiki/Duchenne_muscular_dystrophy
10. https://www.physio-pedia.com/Duchenne_Muscular_Dystrophy
11. "Duchenne muscular dystrophy (DMD) | Muscular Dystrophy Campaign". Muscular-dystrophy.org. Archived from the originalon 2013-01-21. Retrieved 2013-02-16.
Received on 10.07.2021 Modified on 02.08.2021
Accepted on 19.08.2021 © AandV Publications all right reserved
Int. J. Nur. Edu. and Research. 2021; 9(4):512-514.
DOI: 10.52711/2454-2660.2021.00121