Muscular dystrophy is the collective term given to a group of muscle wasting diseases that are hereditary (caused by inheriting a defective gene). Occasionally the parents do not pass on the gene and it occurs spontaneously (a new mutation). There are several different forms of muscular dystrophy. They are:
Congenital Muscular Dystrophy
This type occurs at or very near to birth. The baby will have muscle weakness and stiff or loose joints. They may have respiratory difficulty due to weakness in the muscles that control breathing. They might also suffer seizures, suffer vision problems or be mentally retarded.
Myotonic Muscular Dystrophy
This usually occurs in teenagers and adults, although it can occur in babies as a form of congenital muscular dystrophy. It begins with muscle weakness in the face, forearms, lower legs, neck and hands. Sometimes it can cause respiratory and heart problems, eye problems, gastrointestinal symptoms and occasionally, learning disabilities. It is very slow in its progression and can take as many as 60 years for the full range of symptoms to show.
Duchenne Muscular Dystrophy
This is the most common form of muscular dystrophy and affects mainly boys. Girls can carry the gene for Duchenne's, but they don’t usually display any symptoms. The onset of the disease is at around two to five years of age, starting with muscle wasting of the hips, pelvis, thighs and shoulders. It progresses to affect all of the body’s voluntary muscles, including the respiratory muscles and the heart. Most sufferers will die young and it is rare for a sufferer to reach the age of 30. Globally, the disease affects one in every 3,500 boys born.
Becker Muscular Dystrophy
This is a form of Duchenne’s but it is milder and sufferers usually have a normal life expectancy, although they may be in a wheelchair by the time they reach their 30’s. Occasionally death can occur earlier than normal due to heart complications.
Facioscapulohumeral Muscular Dystrophy
This type of muscular dystrophy affects the facial muscles, shoulders and upper arms. The face may become so weak that the person doesn’t have the strength to smile. The eye muscles can also be affected, sometimes rendering the person unable to close their eyes. This can lead to vision problems through eye damage and difficulty sleeping. The muscles that hold the shoulder blades in place will weaken and the shoulder blades may move out of place. Lifting things may be difficult or impossible.
Limb-girdle Muscular Dystrophy
This type begins in the muscles of the hip and shoulder girdle, hence its name. It more commonly starts in early adulthood. Heart complications can occur in the later stages of the condition.
Emery-Dreifuss Muscular Dystrophy
This type causes wasting of the shoulder, upper arm and calf muscles. Other symptoms include stiff joints and fainting due to heart abnormalities. Sufferers often have to have pacemakers fitted.
Distal Muscular Dystrophy
This type causes wasting of the muscles of the hands, forearms, lower legs and feet. This group of muscles are called the distal muscles. It can occur at any time, is a slow moving condition and sufferers can enjoy a normal lifespan.`
Oculopharyngeal Muscular Dystrophy
This type most often occurs between the 40’s and 60’s. Symptoms include weakness of the facial muscles, eyelids and throat. The sufferer can have difficulty swallowing and keeping their eyes open. Limb weakness can occur in later stages.
Sources: Muscular Dystrophy Association, USA.
NHS Choices, UK.
Joanna is a freelance health writer for The Mother magazine and Suite 101 with a column on infertility, http://infertility.suite101.com/. She is author of the book, 'Breast Milk: A Natural Immunisation,' and co-author of an educational resource on disabled parenting, in addition to running a charity for people damaged by vaccines or medical mistakes.