Muscular Dystrophy

Muscular dystrophy (MD) is a group of diseases that are inherited from parents, and that affects the voluntary muscles (the ones that control movement), as well as other organs in the body. MD can appear at different ages, and goes from mild to severe. The severity is determined in part by the age when it occurs. MD is progressive and some people die young. Nine major forms of muscular dystrophy:
 • MMD, Myotonic, or Steinert's disease.
o Most common form in adults.
o Rarely appears in newborns (congenital MMD).
 o Symptom is a prolonged stiffening of muscles after use, being worse in cold temperatures.
o It causes muscle weakness and affects the central nervous system, heart, gastrointestinal tract, eyes, and hormone-producing glands.
o Short life expectancy.
 • Duchenne.
 o Most common form in children.
 o Affects only males.
o It appears between 2 and 6 years old.
o Muscles decrease in size and get weaker (over time they may appear larger).
o Progression can be different, but 1 in 3,500 will need a wheelchair by age 12.
o Very often, the arms, legs, and spine become progressively deformed.
o There may be some cognitive impairment.
o When very advanced, people develop severe breathing and heart problems.
o People die young.
 • Becker.
 o This form is similar to Duchenne MD, but much milder.
o Symptoms appear later and progress more slowly.
 o It affects only males in a ratio of 1 in 30,000.
 o Causes heart problems.
o Severity varies.
o Can reach their 30s and live further into adulthood.
 • Limb-girdle.
o Appears in the teens to early adulthood.
 o Affects males and females.
 o Causes progressive weakness in the hips and extends to legs, arms, and shoulders.
o Around 20 years in the disease it affects walking to the point of paralysis.
o Affected people may live to middle age, and late adulthood.
• Facioscapulohumeral.
o Refers to the muscles that move the face, shoulder blade, and upper arm bone.
 o Appears from the teen years to early adulthood.
o Affects males and females.
 o Progresses slowly, with short periods of rapid muscle deterioration and weakness.
o Severity ranges from mild to disabling.
o Walking, chewing, swallowing, and speaking problems may occur.
o About 50% of those with this disease can walk and go with their lives.
o Most live a normal life span.
• Congenital MD.
o Means present at birth.
 o Progress slowly and affect males and females.
 o Two forms identified -- Fukuyama and Congenital MD with Myosin deficiency –
 o Cause muscle weakness at birth or in the first few months of life.
 o Causes severe and early shrinking of muscles that will cause joint problems.
o Fukuyama Congenital MD causes abnormalities in the brain and often seizures.
• Oculopharyngeal.
 o Means eye and throat (Muscles affected).
 o This form appears in men and women in their 40s, 50s, and 60s.
o Progresses slowly, causing weakness in the eye and face muscles, which may lead to difficulty swallowing.
 o Weakness in pelvic and shoulder muscles may occur later.
 o Choking and recurrent pneumonia may occur.
 • Distal.
 o Affects adults.
 o Causes weakness and wasting of the distal muscles of the forearms, hands, lower legs, and feet.
o It is less severe, progresses more slowly, and affects fewer muscles than other forms of muscular dystrophy.
• Emery-Dreifuss.
o This is a rare form of MD.
o Appears from childhood to the early teens.
o Affects only males.
o Causes muscle weakness and wasting in the shoulders, upper arms, and lower legs, and can spread to chest and pelvic muscles.
o Heart problems are common; they are life threatening.
 o Muscle shortening (contractures) occurs early in the disease.
o It progresses slowly and causes less severe weakness than other forms of MD.