The common perception is that Muscular dystrophy is one disease; however, it is a group of disorders characterized by progressive muscle weakness and loss of muscle tissue. Some types may lead to muscle deterioration in some disorders that confine the sufferer to a wheelchair. In some forms of this inherited disease, the heart and other involuntary muscles and organs also suffer.There are nine groups of muscular dystrophy. Muscle weakening deterioration and weakening occurs primarily in the arms, legs, and spine, due to a lack of key protein that the muscles need in order to function.
Duchenne’s – Duchenne’s is passed on by a gene on the X chromosome to male children only; it affects about one in 10,000 boys. A woman who has Duchenne dystrophy in her family history should consider genetic testing. Her male fetus has a 50 percent chance of being affected. Prenatal tests can determine the status of the fetus.
Becker's – This form is similar to Duchenne’s muscular dystrophy. It is an X-linked inherited disorder characterized by slowly progressive muscle weakness of the legs and pelvis. Other symptoms and findings include increased difficulty walking, intellectual retardation, fatigue, and heart problems. It usually appears between the ages of two and 16 but can appear as late as age 25. Becker’s affects only males and causes heart problems; disease severity varies. Sufferers can usually walk into their 30s and live further into adulthood.
Facioscapulohumeral – The name of the disorder refers to the muscles in the face, shoulder blade and upper-arm bone. This form appears in teens and young adults—it affects males and females. The disorder progresses slow, with short periods of rapid muscle deterioration and weakness. Severity ranges from mild to completely disabling. Other problems include walking, chewing, swallowing, and speaking. About 50 percent of sufferers can walk and patients usually live a normal life span.
Limb-girdle – This form appears in the teens to early adulthood and affects both males and females. In its most common form, it causes progressive weakness that begins in the hips and moves to the shoulders, arms and legs. Within 20 years, walking becomes difficult or impossible. Patients usually live until mid- to late-adulthood.
Myotonic (also called Steinert’s disease) – This muscular dystrophy is the most common form in adults. Myotonic muscular dystrophy affects both men and women, and it usually appears any time from early childhood to adulthood. In rare congenital cases, it appears in newborns. Myotonia refers to the prolonged spasm or stiffening of muscles. This symptom usually worsens in cold temperatures. The disease causes muscle weakness and also affects the central nervous system, heart, gastrointestinal tract, eyes and hormone-producing glands. In most cases, daily living is not restricted for many years. Patients have a decreased life expectancy.
Myotonia congenital – "Congenital” means present at birth. Congential muscular dystrophies progress slowly and affect males and females. The two forms that have been identified — Fukuyama and congenital muscular dystrophy with merosin deficiency — cause muscle weakness at birth or in the first few months of life, along with severe and early contractures (shortening or shrinking of muscles that causes joint problems). Fukuyama congenital muscular dystrophy causes abnormalities in the brain and, often, seizures.
Emery-Dreifuss – This group of rare diseases affects adult men and women. It causes weakness and wasting of the distal muscles (those farthest from the center) of the forearms, hands, lower legs and feet. It is generally less severe, progresses more slowly, and affects fewer muscles than other forms of muscular dystrophy.
Distal – Disorders are distinguished by the type of inheritance (sex-linked, dominant genes, or recessive gene, and so on), the age when symptoms appear, and the types of symptoms that develop. People are especially at risk who have had a family history of muscular dystrophy.
Oculopharyngeal – Oculopharyngeal refers to the eyes and throat. This form of muscular dystrophy appears in men and women in their 40s, 50s and 60s. It progresses slowly, causing weakness in the eye and face muscles, which may lead to difficulty swallowing. Weakness in pelvic and shoulder muscles may occur later. Recurrent pneumonia and chocking may occur.
