Dominic Stone
Muscular dystrophy (MD) is a genetic condition caused by an altered gene, resulting in progressive weakness and degeneration of skeletal muscles. It is not contagious and cannot be caused by injury or activity. MD affects people worldwide and of all races, although its incidence varies. The condition can manifest in several ways, including Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), congenital muscular dystrophy (CMD), and myotonic dystrophy. The severity and progression of symptoms depend on the specific type of muscular dystrophy, and while there is currently no cure, treatment can help manage the condition.
| Characteristics | Values |
|---|---|
| Cause | Genetic condition caused by an altered gene |
| Gene Mutation | Affects proteins in muscles |
| Gene Changes | Passed from parent to child (inherited) or occurs spontaneously |
| Sex-linked (X-linked) inheritance | Genetic mutation on the X chromosome |
| Gene Protection | Certain genes make proteins that protect muscle fibres |
| Gene Irregularities | Cells that maintain muscles can no longer do so, leading to progressive muscle weakness |
| Gene Types | More than 30 types of MD with different inheritance patterns |
| Gene Testing | Physical, neurological and muscle exams are performed for diagnosis |
| Gene Severity | Severity and speed of symptom progression depend on the type of MD |
| Gene Treatment | No cure, but treatment can help manage symptoms |
| Gene Information | Muscular Dystrophy UK provides support and information |
Explore related products
What You'll Learn
Gene mutations
Muscular dystrophy (MD) is caused by gene mutations that affect proteins in muscles. These mutations are usually inherited but can also occur spontaneously. MD refers to a group of genetic diseases that cause progressive weakness and degeneration of skeletal muscles. These disorders, of which there are more than 30, vary in age of onset, severity, and the pattern of affected muscles. All forms of MD grow worse over time as muscles progressively degenerate and weaken.
The mutations mean that the cells that would normally maintain muscles can no longer do so, leading to progressive muscle weakness. There are several genes and possible genetic mutations that play a role in muscle function, which is why there are so many different forms of muscular dystrophy. In the majority of cases, the genetic mutation is inherited from one or both biological parents. Girls can carry the gene change that causes the disease, and some experience symptoms, but muscular dystrophy is much more common in boys. The most common type, Duchenne muscular dystrophy, usually affects young boys.
Duchenne and Becker muscular dystrophies have this type of inheritance. In rare cases, a person may develop muscular dystrophy spontaneously, meaning the mutation happened randomly and wasn't inherited. This is called a de novo mutation. Duchenne muscular dystrophy (DMD) is the most common form among children, usually affecting children assigned male at birth. DMD is caused by a problem in skeletal muscle producing dystrophin, a protein necessary for typical muscle function. Dystrophin is completely absent in DMD, whereas people with BMD have some, but not enough for normal functioning.
Myotonic dystrophy is the most common type of muscular dystrophy diagnosed in adulthood. It affects men and women equally. People with myotonic dystrophy have difficulty relaxing their muscles after using them. The condition can also affect the heart and lungs and may cause endocrine issues, such as thyroid disease and diabetes. Facioscapulohumeral muscular dystrophy (FSHD) affects the muscles in the face, shoulders, and upper arms. About 4 out of 100,000 people in the US have this form.
How Bruising Impacts Muscle Contraction and Movement
You may want to see also
Explore related products
Inherited or spontaneous
Muscular dystrophy is a genetic condition caused by an altered gene, resulting in progressive weakness and degeneration of skeletal muscles. The altered gene can be inherited from parents or occur spontaneously through gene mutations. While it is not contagious and cannot be induced by injury or activity, it affects people of all races and ages worldwide.
Most cases of muscular dystrophy are caused by gene mutations that affect muscle proteins. These mutations are typically inherited but can also arise spontaneously. In rare instances, a person may develop muscular dystrophy spontaneously due to a de novo mutation, where the mutation occurs randomly and is not inherited. These spontaneous mutations can then be inherited by the affected individual's offspring.
The majority of muscular dystrophy cases are inherited, where individuals inherit the genetic mutation from one or both biological parents. There are three primary inheritance patterns for most forms of muscular dystrophy: autosomal dominant inheritance, autosomal recessive inheritance, and X-linked recessive inheritance. In autosomal dominant inheritance, the child receives a normal gene from one parent and a defective gene from the other. Conversely, in autosomal recessive inheritance, both parents carry and pass on the faulty gene. X-linked recessive inheritance, also known as sex-linked inheritance, occurs when a genetic mutation on the X chromosome causes the condition. Males are more susceptible to developing the condition as they have only one X chromosome, whereas females with two X chromosomes usually exhibit less severe symptoms.
Girls can carry the gene change responsible for muscular dystrophy and may exhibit some symptoms, but the disease is much more prevalent in boys. Duchenne muscular dystrophy, the most common type, predominantly affects young boys, with symptoms typically manifesting in early childhood. Becker muscular dystrophy, a milder variant, tends to affect teens or young adults and progresses more slowly.
Respiratory Muscles: Powering Our Lungs and Breathing
You may want to see also
Explore related products
Duchenne and Becker muscular dystrophies
Duchenne muscular dystrophy is the most common type of muscular dystrophy, usually affecting young boys. Symptoms often start in early childhood and include challenges with movement, such as delayed walking, frequent falls, and trouble with running, jumping, or climbing stairs. These movement difficulties can lead to the use of a wheelchair over time. Duchenne muscular dystrophy can also cause muscle pain and stiffness, as well as learning or behaviour-related challenges.
Becker muscular dystrophy, on the other hand, tends to have milder symptoms that progress more slowly. Symptoms typically start in the teens or early adulthood and may not occur until the mid-20s or later. While Becker muscular dystrophy also causes muscle weakness and degeneration, the onset is generally later in life compared to Duchenne muscular dystrophy.
Both Duchenne and Becker muscular dystrophies are inherited disorders, passed from parent to child through gene mutations. Girls can carry the gene change that causes the disease and may exhibit some symptoms, but the disease is much more common in boys due to the sex-linked (X-linked) inheritance pattern. In rare cases, a person may develop these muscular dystrophies spontaneously due to a de novo mutation that occurs randomly and is not inherited.
Recent advances in molecular therapeutics have led to promising therapies for Duchenne and Becker muscular dystrophies, with some treatments already in clinical trials. These therapies focus on increasing sarcolemmal dystrophin expression and understanding the molecular diagnosis and treatment of these neuromuscular disorders.
Stress-Induced Muscle Cramps: What's the Link?
You may want to see also
Explore related products
Progressive muscle weakness
Muscular dystrophy (MD) is a genetic condition caused by an altered gene or gene mutation, resulting in progressive muscle weakness and degeneration of skeletal muscles. This progressive muscle weakness is due to the lack of a protein called dystrophin, which is necessary for typical muscle function. The altered gene can be passed on from parents to children, known as inheritance, or can be present from birth even if the parents do not have the altered gene. MD is not contagious and cannot be caused by injury or activity.
There are various types of muscular dystrophy, each caused by a specific gene change unique to that type. For example, Duchenne muscular dystrophy (DMD) is the most common type among children, predominantly affecting those assigned male at birth. It is caused by a problem in skeletal muscle producing dystrophin, which is completely absent in DMD. Becker muscular dystrophy (BMD), on the other hand, is characterised by reduced levels of dystrophin, resulting in similar but milder symptoms compared to DMD.
Myotonic dystrophy, the most common type diagnosed in adulthood, affects both men and women equally. It causes difficulty in relaxing muscles after use, impacting the heart, lungs, and endocrine system. Facioscapulohumeral muscular dystrophy (FSHD) affects the muscles in the face, shoulders, and upper arms and tends to progress slowly, with symptoms typically appearing before the age of 20. Limb-girdle muscular dystrophy (LGMD) affects the muscles in the upper arms, upper legs, shoulders, and hips and can occur at any age.
The symptoms of muscular dystrophy vary in severity and progression. Some individuals experience mild symptoms, while others develop life-threatening complications involving the heart, lungs, or other organs. Progressive muscle weakness can lead to difficulties in walking, swallowing, and breathing. Over time, individuals with MD may require mobility equipment, such as wheelchairs, and breathing assistance devices. MD can affect quality of life and lifespan, depending on the specific symptoms and their impact.
Thyroid Disorders: Muscle Weakness and Fatigue
You may want to see also
Explore related products
$7.87 $18.99
Muscles affected: face, shoulders, arms, legs, heart, lungs
Muscular dystrophy (MD) is caused by gene mutations that affect proteins in muscles. These mutations are usually inherited but can also occur spontaneously. MD refers to a group of more than 30 genetic conditions that affect muscle function. While there are many types of MD, this response will focus on the muscles affected, including the face, shoulders, arms, legs, heart, and lungs.
Face
Facioscapulohumeral muscular dystrophy (FSHD) is a type of MD that initially affects the muscles of the face, shoulders, and upper arms. Symptoms of FSHD usually appear before the age of 20 and tend to affect one side of the body more than the other. When muscles around the eyes are affected, it can cause trouble fully closing the eyelids and lead to eye dryness. Facial muscles are also often the first to be affected in myotonic dystrophy, which is the most common type of muscular dystrophy diagnosed in adulthood.
Shoulders, Arms, and Legs
Emery-Dreifuss muscular dystrophy (EDMD) causes muscle weakness in the shoulders, upper arms, and shins. Limb-girdle muscular dystrophy (LGMD) affects the muscles in the upper arms, upper legs, shoulders, and hips. Both EDMD and LGMD usually progress slowly. MD can also cause muscle pain and stiffness in the upper arms, shoulders, upper legs, and pelvis.
Heart
Some types of MD can affect the heart, including EDMD, FSHD, and Duchenne muscular dystrophy (DMD). Heart rhythm issues can be the first complication for some people with MD, and the condition can lead to heart failure (cardiomyopathy). Early treatment with certain medications may slow the progression of cardiomyopathy and prevent the onset of heart failure.
Lungs
MD can affect the muscles involved in breathing, including the muscles used to cough. This can make it hard for the body to remove mucus from the lungs and windpipe. Respiratory care, such as cough-assist devices and respirators, can help with breathing. DMD and Becker muscular dystrophy (BMD) can also affect the lungs. Corticosteroids may be beneficial for improving lung function.
Potassium Deficiency: Muscle Weakness and Fatigue
You may want to see also
Frequently asked questions
Muscular dystrophy (MD) is a group of genetic diseases that cause progressive weakness and degeneration of skeletal muscles. There are more than 30 types of MD, and they vary in age of onset, severity, and the pattern of the affected muscles.
MD is caused by gene mutations that affect proteins in muscles. These mutations are usually inherited but can also occur spontaneously.
The symptoms of MD vary depending on the type but can include muscle weakness, difficulty walking, trouble with movement, breathing issues, heart problems, curved spine (scoliosis), intellectual disabilities, and learning disorders.
