MD Flashcards
What are muscular dystrophies?
Inherited, genetic, disorder causing progressive muscle weakness & atrophy
If a disorder is X-linked what does that mean?
Mutation in one of the mother’s X chromosomes; may not be passed to offspring, may be passed to daughter who is an asymptomatic carrier, may be passed to a son who will develop the disease
If a disorder is autosomal dominant what does that mean?
You only need to get the abnormal gene from one parent who has it
If a baby boy presents with weakness that starts in the trunk and spreads to the legs first and on labs you see elevated CK, what does he have?
Duchenne Muscular Dystrophy
What is the pathogenesis of Duchenne Muscular Dystrophy?
X-linked defective gene causing dystrophin deficiency thus leading to muscle breakdown
Is there any treatment for Duchenne MD?
corticosteroids, but prognosis is wheelchair by 12 and survival into late teens/20’s
What if the boy is older presenting with central weakness that then spreads to the legs, with only low dystrophin levels?
Then it is known as Becker Muscular Dystrophy
For Becker disease or Duchenne what are some of the complications and reasons why lifespan is shorter?
cardiomyopathy, respiratory infections, fractures, cognitive impairment
Becker = live to 40’s Duchenne = Live to teens/20’s
For Becker or Duchenne how do you make the diagnosis?
Exam, CK, AST, ALT, genetic testing, EMG, and muscle biopsy
Besides corticosteroids for Becker or Duchenne, what other treatment can you offer?
Ca/Vit D (for fractures); ACE & Beta Blockers (for Cardiomyopathy); Defibrillator (cardiomyopathy); Pulm support
If a young patient presents with contractures at the elbows, ankle plantar flexion, and spine, what diagnosis?
Emery-Dreifuss MD
How do you diagnosis Emery-Dreifuss MD and what are some of the complications?
EMG & genetic testing.
Complications = arrhythmias and cardiomyopathies
Most still ambulate 20 years after diagnosis
If a patient finds that he goes to shake a person’s hand and cannot relax or let it go, what is this?
Myotonic Dystrophy
What type of MD is the most common?
Myotonic Dystrophy
If a patient develops MD as an adult or child with baldness, fatigue, and cataracts along with muscle stiffness?
Type 1 Myotonic Dystrophy