Muscular dystrophy (MD) represents a group of inherited muscle disorders that primarily cause muscle weakness and muscle wasting, though some types of the disease also present with other characteristics. MD can begin in infancy or childhood, or later in life. Diagnosis typically begins with an evaluation of symptoms but is only confirmed after significant testing. While there’s no known cure for muscular dystrophy, treatments may help slow progression and improve symptoms.
Muscular dystrophy is caused by a lack of certain proteins that are needed for muscle structure and function. Specifically, many of the types of MD are caused by a lack of a protein called dystrophin, which helps optimize muscle function.
Most types of muscular dystrophy are hereditary diseases. Researchers have discovered more than 30 genes responsible for causing different types of MD and genetic testing can assess your risk of passing on these genes to your children.
Some types of muscular dystrophy can be fatal. Certain types, including Duchenne muscular dystrophy, can lead to problems with the heart and muscles used for breathing. Some people with MD may develop other life-threatening complications as well, including aspiration pneumonia (a lung infection) due to difficulties with eating and swallowing.
Becker muscular dystrophy tends to appear later than the most common form of the disease, Duchenne MD (DMD). Symptoms may appear as late as age 25. Becker MD also progresses slower than DMD and is typically milder.
Congenital means present at or before birth, so a congenital condition or disease is one that you’re born with. Congenital muscular dystrophy, however, isn’t a single disease; it’s a group of muscular dystrophies that are all congenital. Unlike some forms that primarily affect boys, these types affect all genders.
Duchenne muscular dystrophy (DMD) is the most common childhood form of muscular dystrophy, with symptoms typically beginning between ages 2 and 6. It mostly affects boys, though girls may be mildly affected. It can cause potentially life-threatening complications due to the weakening of the heart and muscles involved in breathing.
Electromyography is a test that uses electrodes to examine the electrical signals sent by the nerves in your muscles. They help doctors identify diseases that affect the nerves and muscles as well as the extent of any damage. This test is used to diagnose myotonic muscular dystrophy, which causes muscles to stay contracted for an abnormally long time.
Facioscapulohumeral muscular dystrophy (FSH MD) begins in adolescence or early adulthood and affects both genders. FSH MD primarily affects the muscles of the face, shoulder blades, and upper arms. It often makes the shoulders slope forward and causes difficulty raising the arms.
A gene mutation is a permanent alteration in one or more genes. Mutations cause changes in a particular gene’s instructions for making a protein. That leads to proteins that are missing or malfunctioning, which leads to disease. Most forms of muscular dystrophy are caused by genetic mutations.
Genetic diseases result from mutations to a parent’s gene that are then passed on to their child or children, causing illness. Most forms of muscular dystrophy are genetic diseases. If MD runs in your family, you can get genetic testing to see if you carry the gene and could therefore pass it on to a child.
Genetic testing involves examining your genes, chromosomes, or proteins for evidence of mutations. This may be done to:
Women can be tested to see whether they carry a gene mutation for some types of muscular dystrophy and could pass it on to a child.
Limb-girdle muscular dystrophy is a form of MD that develops in teenagers or young adults. Symptoms first become apparent in the hips, then the shoulders, and then the limbs (hence the name). This slowly progressing form of the muscle-wasting disease impacts all genders, unlike some types that are primarily found in boys.
Also known as Steinert's disease or MMD, this is the most common form of adult muscular dystrophy. It starts with muscle weakness in the face and then moves on to the feet and hands. A woman with myotonic MD can give birth to an infant with a congenital form of the disease.