Muscular dystrophy (MD) is a genetic disorder characterized by progressive weakening of muscles that result in an increasing level of disability. Muscular dystrophy is actually a group of inherited diseases which cause different symptoms and progress at different speed.
Muscular dystrophy occurs due to genetic abnormalities. Each form of MD is associated with a specific genetic mutation that causes changes in muscle fibers thus affecting the structure and functioning of muscles. These genetic mutations usually run in families but may sometimes occur spontaneously.
Forms of Muscular Dystrophy
Muscular dystrophy includes more than 30 disorders. Each form of muscular dystrophy differs by symptoms, the age at which symptoms begin, pattern of progression and rate of progression. Given below are the most common forms of muscular dystrophy:
Duchenne Muscular Dystrophy (DMD)
This is the most common form of the disease that affects boys. The symptoms usually start around the age of 3. Duchenne MD is the most severe form of muscular dystrophy that quickly progresses and the affected individual usually needs a wheelchair by the age of 12. The sufferers are often mentally challenged and rarely survive beyond late teens.
Becker Muscular Dystrophy (BMD)
This type is closely related to Duchenne MD but is less severe and not as common. It also affects only boys and usually starts around the age of 10. The disease progresses more slowly and the sufferers may live longer without the use of a wheal chair.
Myotonic Muscular Dystrophy (MMD)
It is the most common type of MD in adults but the symptoms may appear at any age from early childhood to adulthood. Both genders can be affected by this disorder. Myotonic muscular dystrophy causes weakness of small muscles such as those in the face, jaw, neck and hands.
Limb-girdle Muscular Dystrophy (LGMD)
This form of MD affects muscles in the shoulder, upper arms, thighs and hips. It equally affects boys and girls. It may begin in childhood or early adulthood. There are around 15 types of Limb-girdle muscular dystrophy.
Facioscapulohumeral Muscular Dystrophy (FSHD)
This form of the disease involves weakness of the muscles in the face, shoulders and upper arms. It usually appears in the teens or early adulthood and can affect both males and females.
Oculopharyngeal Muscular Dystrophy
This is slowly progressing form of muscular dystrophy that causes weakness in the eye and throat muscles. Both men and women can be affected and the symptoms usually start between the ages of 40 and 60.
Prevention of Muscular Dystrophy
Muscular dystrophy caused by spontaneous gene mutation cannot be prevented. However, couples with family history of MD should undergo genetic testing that can identify carriers of the disorder. The carriers are individuals who carry the defected gene but do not exhibit symptoms and may pass the condition on their child.
Genetic testing can be also used for prenatal diagnosis. This is done using amniocentesis in which a small sample of amniotic fluid is taken for analysis. An unborn baby may be diagnosed with MD if the cells from amniotic fluid have genetic mutation responsible for the disorder. However, prenatal diagnosis is not 100% accurate and if genetic mutation is present it does not necessarily means that the baby will have symptoms of MD once it is born.