What is muscular dystrophy?
Muscular dystrophy (MD) is a collective term for a range of neuromuscular conditions.
It is characterised by the progressive weakening and wasting of muscles.
The most common form of the condition is known as Duchenne MD, which only affects
males. Sufferers of this form eventually lose the ability to walk, usually between
the ages of eight and 11. Other forms of MD can be less severe, progress more
slowly and affect men and women equally.
What causes MD?
MD is caused by a defect
in the gene which makes up the muscles. If a person has this defect, they can
pass it on to their children. Depending on the way it is inherited, the children
may then develop MD or may simply be a carrier of the gene.
MD has been known to develop where there is no known family history of it.
It is thought that in such cases, there is a spontaneous mutation of the gene.
Duchenne MD is known to result from a defect in a single important protein in
muscles called dystrophin.
What are the symptoms of MD?
The degree of muscle weakness depends on the type of MD. When the condition
develops in childhood, symptoms include floppiness as a baby or difficulty standing
up and walking as a toddler. The weakness usually gets worse over time.
Boys with Duchenne MD show a difficulty in walking between the ages of one
and three. They eventually lose the ability to walk, usually between the ages
of eight and 11.
How is MD diagnosed?
Genetic testing can be used to determine if someone carries the defective gene.
There is a Centre for Medical Genetics located at Our Lady's Hospital for Sick
Children Crumlin in Dublin.
A person suspected of having MD may be referred to a muscle diagnosis clinic,
where a muscle biopsy and genetic testing will enable diagnosis of the type
of MD. Only specialised hospital departments have the facilities for doing muscle
biopsies of a high enough quality to give fully reliable results.
MD can sometimes be diagnosed before birth, but not always. The test is performed
on a tiny piece of the developing placenta, usually at about the 10th
week of pregnancy.
How is it treated?
There is currently no cure for MD, therefore the main aim of treatment is to
make the quality of life as good as possible for a person with the condition.
Gentle exercise is recommended and physiotherapy can help to prevent the development
of contractures (thickening and scarring of muscle and connective tissue resulting
in deformity of a joint).
Scoliosis (curvature of the spine) can develop and in such cases, surgery may
be beneficial. The use of electric wheelchairs means that people with MD can
still be mobile and maintain independence.
In the latter stages of some types of MD, including Duchenne MD, respiratory
problems may develop. For this reason, it is recommended that any chest infections
are treated immediately and people with MD and those around them should not
In severe cases, assisted ventilation may be required. A nasal tube or face
mask may be used but eventually a tracheostomy may be considered for some people.
(A tracheostomy is a surgical operation in which a hole is made into the trachea
through the neck to relieve obstruction to breathing.)
Where can I find more information on MD?
Muscular Dystrophy Ireland is a voluntary organisation which offers a range
of services to people with MD and their families, including family support,
respite care and youth activities.