Muscular dystrophy (MD) is a genetic (inherited) condition that gradually causes the muscles to weaken. This leads to an increasing level of disability.
MD is a progressive condition, which means that it gets worse rather than better. It often affects a particular group of muscles, before moving on to other muscles. If MD begins to affect the heart or the muscles used for breathing, it becomes life-threatening.
What causes muscular dystrophy?
MD is caused by mutations (changes) in the genes that are responsible for the structure and functioning of a person’s muscles. These mutations cause changes in the muscle fibres, which interfere with the muscles' ability to function. Over time, this causes increasing disability. Read more information about the causes of MD.
The mutations are often inherited from a person’s parents. If there is a known family history of MD, your GP may be able to refer you for genetic testing and counselling, to give you more information about preventing MD.
Types of muscular dystrophy
There are more than 30 types of MD, each with slightly different symptoms. Not all types of MD cause severe disability.
Some of the more common types of MD are listed below. Read more detailed information about the symptoms of MD.
Duchenne muscular dystrophy
Duchenne MD is the most common and one of the most severe forms of MD. It usually affects boys and is diagnosed at around three years of age. It starts in the leg muscles before quickly progressing to other muscle groups.
Children with Duchenne MD may be in a wheelchair by 8-12 years old and have a limited life expectancy. While people with Duchenne MD used to be expected to live only into their teens, today most people with Duchenne MD survive well into their 20s and sometimes longer.
Becker muscular dystrophy
Becker MD is closely related to Duchenne MD, but it is milder and less common. Like Duchenne MD, Becker MD tends to affect boys, although it is not usually diagnosed until a child reaches about school age. It also progresses more slowly. Those with Becker MD can walk at least until their late teenage years, and often much longer, sometimes until 40-50 years old or more.
Myotonic muscular dystrophy
Myotonic MD is the most common form of MD in men and women. It can present at any age, even before birth. It can affect many parts of the body, including the muscles, heart and eyes. It is important for this to be diagnosed because of possible problems under anaesthetic and complications for an affected woman in childbirth.
Limb-girdle muscular dystrophy
Limb-girdle MD has around 15 different varieties. It can affect both sexes and usually appears in early adulthood. Limb-girdle MD initially starts in the muscles around the hip and shoulder, but it can also progress quite quickly to other areas.
Facioscapulohumeral muscular dystrophy
Facioscapulohumeral MD affects the muscles in the face (facio), shoulders (scapula) and upper arm (humeral). It can affect both sexes. Symptoms start in childhood or adult life and usually progress slowly.
Oculopharyngeal muscular dystrophy
Oculopharyngeal MD affects the muscles of the eye (ocular) and throat (pharyngeal). The condition affects both sexes, usually starting in middle age.
How common is muscular dystrophy?
More than 70,000 children and adults in the UK have a type of muscle disease or related condition. Duchenne MD is the most common type of MD and affects around one boy in every 3,500 in the UK. The second most common type is myotonic MD, which affects around one person in every 8,000.
What treatment is available?
Although there is no cure for any of the different types of MD, a range of treatments for MD can help with the physical disabilities and heart problems. These may include:
- mobility assistance - including exercise, physiotherapy and physical aids
- support groups - to help deal with the practical and emotional impact of MD
- surgery - to correct postural deformities such as scoliosis
- medication - such as steroid medication to improve muscle strength, or ACE inhibitors and beta-blockers to treat heart problems
New research is looking into ways of repairing the genetic mutations and damaged muscles and has reached the stage of promising clinical trials for Duchenne MD. Search clinical trials for muscular dystrophy.
