Defective genes, genetic mutations
Inherited defective genes
These genetic “errors” affect muscle fiber
Symptoms and signs
Duchenne muscular dystrophy:
Usually affects boys
Occurrence: between 2 and 6 years of age
Trouble keeping balance – frequent falls
Tendency to walk on toes
Difficulty in getting up
Difficulty in running, jumping
Progressive deformation of the spine
Becker muscular dystrophy:
Similar symptoms to Duchenne
Specific: slower progression of the disease, milder symptoms
Usual occurrence: teen years, mid 20’s
Myotonic muscular dystrophy (MMD or Steinert’s disease):
Inability to voluntarily relax muscles
Prolonged muscle spasms
Usually affects neck and face muscles
Muscle weakness in face and shoulders
Usual symptom occurrence: teen years to 40 years
Affects both sexes
Difficulties in swallowing, chewing, speaking
Affects both sexes
Present from birth or first months of life
Contractures of the muscles
Possible abnormalities of the brain
Weakness in hips that progresses to the shoulders, arms and legs
Usual occurrence: teen years to early adulthood
Personal medical history and family medical history is checked by the doctor
After a physical examination further tests may be recommended
Blood tests: enzyme test (a high level of certain enzymes could indicate muscle disease), genetic testing (to check for gene mutation)
Electromyography (an electrode needle measures the electrical activity of the muscle)
Heart and lung monitoring tests (used to check heart and lung function especially in cases diagnosed with myotonic muscular dystrophy)
Muscular dystrophy has no cure, but treatment is focused on managing symptoms and maintaining the person’s mobility for as long as it is possible
Medication: corticosteroids (to improve muscle strength and delay the disease’s progression), angiotensin-converting enzyme (ACE) inhibitors or beta blockers (in case of heart damage)
Recommended therapies: exercise (low-impact: swimming, walking, light aerobics, stretching)
Assistive devices: braces, canes, wheelchairs, sleep apnea machine (in the case of respiratory complications)
Surgery may be recommended to correct exaggerated curvatures of the spine that cause heart or lung problems
Milkshakes and protein supplements can prevent muscle dystrophy.
Prenatal testing cannot determine the presence of Duchenne/Becker muscular dystrophy.
Physical activity should be completely avoided.
The cause of muscle dystrophy cannot be genetic if there is not at least one family member that suffers from it.
Over 50,000 Americans are affected by some type of muscular dystrophy
In the US, 1 in 5,600 to 7,700 males are affected by Duchenne or Becker muscular dystrophy (ages 5-24)
In the age group of 10-14 years: 82% of the males with Duchenne or Becker muscle dystrophy use a wheelchair
Myotonic dystrophy is the most common muscular dystrophy to affect adults.
People with Duchenne muscular dystrophy usually do not live past 25 years.
There are around 27 drugs that are in different testing stages for Duchenne MD.