The muscular dystrophies (MD) are a group of inherited genetic conditions that gradually cause the muscles to weaken, leading to an increasing level of disability.
MD is a progressive condition, which means it gets worse over time. It often begins by affecting a particular group of muscles, before affecting the muscles more widely.
Some types of MD eventually affect the heart or the muscles used for breathing, at which point the condition becomes life-threatening.
There's no cure for MD, but treatment can help to manage many of the symptoms.
What causes muscular dystrophy?
MD is caused by changes (mutations) in the genes responsible for the structure and functioning of a person's muscles.
The mutations cause changes in the muscle fibres that interfere with the muscles' ability to function. Over time, this causes increasing disability.
The mutations are often inherited from a person's parents. If you have a family history of MD, your GP may refer you for genetic testing and counselling to evaluate your risk of developing the condition or having a child with MD and to discuss the options available to you.
Read more about the causes of MD and genetic testing for MD.
Types of muscular dystrophy
There are many different types of MD, each with somewhat different symptoms. Not all types cause severe disability and many don't affect life expectancy.
Some of the more common types of MD include:
Duchenne MD – one of the most common and severe forms, it usually affects boys in early childhood; people with the condition will usually only live into their 20s or 30s
myotonic dystrophy – a type of MD that can develop at any age; life expectancy isn't always affected, but people with a severe form of myotonic dystrophy may have shortened lives
facioscapulohumeral MD – a type of MD that can develop in childhood or adulthood; it progresses slowly and isn't usually life-threatening
Becker MD – closely related to Duchenne MD, but it develops later in childhood and is less severe; life expectancy isn't usually affected as much
limb-girdle MD – a group of conditions that usually develop in late childhood or early adulthood; some variants can progress quickly and be life-threatening, whereas others develop slowly
oculopharyngeal MD – a type of MD that doesn't usually develop until a person is between 50 and 60 years old, and doesn't tend to affect life expectancy
Emery-Dreifuss MD – a type of MD that develops in childhood or early adulthood; most people with this condition will live until at least middle age
Who's affected by muscular dystrophy?
In the UK, around 70,000 people have MD or a related condition.
Duchenne MD is the most common type of MD. In the UK, about 100 boys are born with Duchenne MD each year, and there are about 2,500 people living with the condition in the UK at any one time.
Myotonic MD is the second most common type of MD, affecting around 1 person in every 8,000.
Facioscapulohumeral MD is thought to affect around 1 in every 20,000 people in the UK, making it the third most common MD.
Diagnosing muscular dystrophy
Many different methods can be used to diagnose the various types of MD. The age at which the condition is diagnosed will vary depending on when symptoms first start to appear.
Diagnosis will involve some or all of the following stages:
investigating any symptoms
discussing any family history of MD
electrical tests on the nerves and muscles
a muscle biopsy (where a small tissue sample is removed for testing)
See a GP if you or your child has any symptoms of MD. If necessary, they may refer you to a hospital for further tests.
Treating muscular dystrophy
There's no cure for MD, but a range of treatments can help with the physical disabilities and problems that may develop. These can include:
mobility assistance – including exercise, physiotherapy and physical aids
support groups – to deal with the practical and emotional impact of MD
surgery – to correct postural deformities, such as scoliosis
New research is looking into ways of repairing the genetic mutations and damaged muscles associated with MD.
Read more about treating MD.