Duchenne muscular dystrophy
Pseudohypertrophic muscular dystrophy; Muscular dystrophy - Duchenne typeDuchenne muscular dystrophy is an inherited disorder. It involves muscle weakness, which quickly gets worse.
Muscle weakness
Weakness is reduced strength in one or more muscles.
Read Article Now Book Mark ArticleCauses
Duchenne muscular dystrophy is a form of muscular dystrophy. It worsens quickly. Other muscular dystrophies (including Becker muscular dystrophy) get worse much more slowly.
Muscular dystrophy
Muscular dystrophy (MD) is a group of inherited disorders that cause muscle weakness and loss of muscle tissue, which get worse over time.
Read Article Now Book Mark ArticleBecker muscular dystrophy
Becker muscular dystrophy is an inherited disorder that involves slowly worsening muscle weakness of the legs and pelvis.
Read Article Now Book Mark ArticleDuchenne 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.
Protein
Proteins are the building blocks of life. Every cell in the human body contains protein. The basic structure of protein is a chain of amino acids. ...
Read Article Now Book Mark ArticleThe 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 3,600 male infants. Because this is an inherited disorder, risks include a family history of Duchenne muscular dystrophy.
Symptoms
Symptoms most often appear before age 6. They may start as early as infancy. Most boys show no symptoms in the first few years of life.
Symptoms may include:
- Fatigue
Fatigue
Fatigue is a feeling of weariness, tiredness, or lack of energy.
Read Article Now Book Mark Article - Learning difficulties (the IQ can be below 75).
- Intellectual disability (possible, but does not get worse over time).
Muscle weakness:
- Begins in the legs and pelvis, but also occurs less severely in the arms, neck, and other areas of the body.
- Problems with motor skills (running, hopping, jumping).
- Frequent falls.
- Trouble getting up from a lying position or climbing stairs.
- Shortness of breath, fatigue, and swelling of the feet due to a weakening of the heart muscle.
- Problem breathing due to a weakening of the respiratory muscles.
- Gradual worsening of muscle weakness.
Progressive difficulty walking:
Difficulty walking
Walking abnormalities can be caused by many different types of problems. Problems with the joints, (such as arthritis), bones (such as deformities),...
Read Article Now Book Mark Article- Ability to walk may be lost by age 12, and the child will have to use a wheelchair.
- Breathing difficulties and heart disease usually start by age 20.
Exams and Tests
A complete nervous system (neurological), heart, lung, and muscle exam may show:
- Abnormal, weak heart muscle (cardiomyopathy) that becomes evident by age 10
Cardiomyopathy
Cardiomyopathy is disease in which the heart muscle becomes weakened, stretched, or has another structural problem. It often contributes to the hear...
Read Article Now Book Mark Article - Congestive heart failure or irregular heart rhythm (arrhythmias) that is present in all people with Duchenne muscular dystrophy by the age of 18
Congestive heart failure
Heart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...
Read Article Now Book Mark ArticleArrhythmias
An arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregul...
Read Article Now Book Mark Article - Deformities of the chest and back (scoliosis)
Scoliosis
Scoliosis is an abnormal curving of the spine. Your spine is your backbone. It runs straight down your back. Everyone's spine naturally curves a b...
Read Article Now Book Mark Article - Enlarged muscles of the calves, buttocks, and shoulders (around age 4 or 5). These muscles are eventually replaced by fat and connective tissue (pseudohypertrophy).
- Loss of muscle mass (wasting)
Wasting
Muscle atrophy is the wasting (thinning) or loss of muscle tissue.
Read Article Now Book Mark Article - Muscle contractures in the heels, legs
Muscle contractures
Muscle cramps are when a muscle gets tight (contracts) without you trying to tighten it, and it does not relax. Cramps may involve all or part of on...
Read Article Now Book Mark Article - Muscle deformities
- Respiratory disorders, including pneumonia and swallowing with food or fluid passing into the lungs (in late stages of the disease)
Pneumonia
Pneumonia is a breathing (respiratory) condition in which there is an infection of the lung. This article covers community-acquired pneumonia (CAP). ...
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Tests may include:
- Blood creatine kinase levels
- Electrocardiogram (ECG)
- Cardiac testing
- X-rays of the spine to determine if there is a scoliosis
- Pulmonary function tests
- Electromyography (EMG)
EMG
Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles.
Read Article Now Book Mark Article - Genetic tests
- Muscle biopsy
Muscle biopsy
A muscle biopsy is the removal of a small piece of muscle tissue for examination.
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Treatment
There is no known cure for Duchenne muscular dystrophy. Treatment aims to control symptoms to improve quality of life.
Steroid drugs can slow the loss of muscle strength. They may be started when the child is diagnosed or when muscle strength begins to decline.
Other treatments may include:
- Albuterol (to help with muscle strength)
- Amino acids
- Carnitine
- Coenzyme Q10
- Creatine
- Fish oil
- Green tea extracts
- Vitamin E
However, the effects of these treatments have not been proven. Stem cells and gene therapy may be used in the future.
Genetic therapies may be helpful to certain patients, depending on the genetic cause. Each therapy only works on a small number of patients, depending on their specific genetic change (mutation). While these treatments have been shown to increase dystrophin production, they have not yet been shown to have significant clinical benefits. Treatments include:
- Eteplirsen
- Golodirsen
- Vitolarsen
- Casimersen
- Ataluren
- Delandistrogene moxeparvovec
The use of steroids and the lack of physical activity can lead to excessive weight gain. Activity is encouraged. Inactivity (such as bedrest) can make the muscle disease worse. Physical therapy may help to maintain muscle strength and function. Speech therapy is often needed.
Other treatments may include:
- Assisted ventilation (used during the day or night)
- Drugs to help heart function, such as angiotensin-converting-enzyme inhibitors, beta-blockers, and diuretics
- Orthopedic appliances (such as braces and wheelchairs) to improve mobility
- Spine surgery to treat progressive scoliosis for some people
- Proton pump inhibitors (for people with gastroesophageal reflux)
Several new treatments are being studied in trials.
Support Groups
You can ease the stress of illness by joining a support group where members share common experiences and problems. The Muscular Dystrophy Association is an excellent source of information on this disease.
Stress
Stress is a feeling of emotional or physical tension. It can come from any event or thought that makes you feel frustrated, angry, or nervous. Stres...
Read Article Now Book Mark ArticleSupport group
Local and national support groups can be found on the web, through local libraries, your health care provider, and the yellow pages under "social ser...
Read Article Now Book Mark ArticleMuscular Dystrophy Association
The following organizations are good resources for information on muscular dystrophy:Centers for Disease Control and Prevention -- www. cdc. gov/musc...
Read Article Now Book Mark ArticleOutlook (Prognosis)
Duchenne muscular dystrophy leads to progressively worsening disability. Death often occurs from lung disorders, although advances in supportive care have resulted in many men living to age 35 years.
Possible Complications
Complications may include:
- Cardiomyopathy
- Congestive heart failure (rare)
- Deformities
- Heart arrhythmias (rare)
- Mental impairment (varies, usually minimal)
- Permanent, progressive disability, including decreased mobility and decreased ability to care for self
- Pneumonia or other respiratory infections
- Respiratory failure
When to Contact a Medical Professional
Contact your health care provider if:
- Your child has symptoms of Duchenne muscular dystrophy
- Symptoms get worse, or new symptoms develop, particularly fever with cough or breathing problems
Prevention
People with a family history of the disease may want to seek genetic counseling. Genetic studies done during pregnancy are very accurate in detecting Duchenne muscular dystrophy.
References
Bharucha-Goebel DX. Muscular dystrophies. In: Kliegman RM, St Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 627.
Genetic and Rare Diseases Information Center (GARD). Duchenne muscular dystrophy. rarediseases.info.nih.gov/diseases/6291/duchenne-muscular-dystrophy. Updated June 2024. Accessed June 11, 2024.
Lee BH. The Dystrophinopathies. Continuum (Minneap Minn). 2022;28(6):1678-1697. PMID: 36537975 pubmed.ncbi.nlm.nih.gov/36537975/.
Muscular Dystrophy Association website. Duchenne muscular dystrophy. www.mda.org/disease/duchenne-muscular-dystrophy. Accessed March 5, 2024.
Selcen D. Muscle diseases. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 389.
Warner WC, Sawyer JR. Neuromuscular disorders. In: Azar FM, Beaty JH, eds. Campbell's Operative Orthopaedics. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 35.
X-linked recessive genetic defects - how boys are affected - illustration
There are several X-linked (or sex-linked) recessive genetic disorders, (hemophilia, muscular dystrophy) which are inherited through a genetic defect on an X chromosome. A female has 2 X chromosomes, one she inherited from her mother and one she got from her father. A male has an X chromosome from his mother and a Y chromosome from his father. Since male offspring receive their X chromosome from their mothers, the inheritance of a defect attached to that one copy of the X will cause the disorder.
X-linked recessive genetic defects - how boys are affected
illustration
X-linked recessive genetic defects - how girls are affected - illustration
There are several X-linked (or sex-linked) recessive genetic disorders, (hemophilia, muscular dystrophy) which are inherited through a genetic defect on an X chromosome. A female has 2 X chromosomes, one she inherited from her mother and one she got from her father. A male has an X chromosome from his mother and a Y chromosome from his father. Females may get the defective gene either from her mother's defective X, or, if her father has the disorder, from her father. In either case, the girl will be a carrier and will probably pass the defect to her offspring. She will not manifest the disorder the way a boy would, because she has 2 X chromosomes, and the dominant X will compensate for the defect on the recessive X. Only if a female has 2 parents with the defect on their X chromosomes will she get a milder form of the disorder.
X-linked recessive genetic defects - how girls are affected
illustration
X-linked recessive genetic defects - illustration
There are several X-linked (or sex-linked) recessive genetic disorders, (hemophilia, muscular dystrophy) which are inherited through a genetic defect on an X chromosome. A female has 2 X chromosomes, one she inherited from her mother and one she got from her father. A male has an X chromosome from his mother and a Y chromosome from his father. If a woman has the defect on one of her X chromosomes, and the father's X chromosome is normal, there is a 25% chance for each pregnancy to produce an unaffected girl; a girl who carries the defect; an unaffected boy; or a boy with the disorder.
X-linked recessive genetic defects
illustration
X-linked recessive genetic defects - how boys are affected - illustration
There are several X-linked (or sex-linked) recessive genetic disorders, (hemophilia, muscular dystrophy) which are inherited through a genetic defect on an X chromosome. A female has 2 X chromosomes, one she inherited from her mother and one she got from her father. A male has an X chromosome from his mother and a Y chromosome from his father. Since male offspring receive their X chromosome from their mothers, the inheritance of a defect attached to that one copy of the X will cause the disorder.
X-linked recessive genetic defects - how boys are affected
illustration
X-linked recessive genetic defects - how girls are affected - illustration
There are several X-linked (or sex-linked) recessive genetic disorders, (hemophilia, muscular dystrophy) which are inherited through a genetic defect on an X chromosome. A female has 2 X chromosomes, one she inherited from her mother and one she got from her father. A male has an X chromosome from his mother and a Y chromosome from his father. Females may get the defective gene either from her mother's defective X, or, if her father has the disorder, from her father. In either case, the girl will be a carrier and will probably pass the defect to her offspring. She will not manifest the disorder the way a boy would, because she has 2 X chromosomes, and the dominant X will compensate for the defect on the recessive X. Only if a female has 2 parents with the defect on their X chromosomes will she get a milder form of the disorder.
X-linked recessive genetic defects - how girls are affected
illustration
X-linked recessive genetic defects - illustration
There are several X-linked (or sex-linked) recessive genetic disorders, (hemophilia, muscular dystrophy) which are inherited through a genetic defect on an X chromosome. A female has 2 X chromosomes, one she inherited from her mother and one she got from her father. A male has an X chromosome from his mother and a Y chromosome from his father. If a woman has the defect on one of her X chromosomes, and the father's X chromosome is normal, there is a 25% chance for each pregnancy to produce an unaffected girl; a girl who carries the defect; an unaffected boy; or a boy with the disorder.
X-linked recessive genetic defects
illustration
Review Date: 12/31/2023
Reviewed By: Joseph V. Campellone, MD, Department of Neurology, Cooper Medical School at Rowan University, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 06/11/2024.