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Flashcards in Child Health - Muscular Dystrophy Deck (7)
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Duchenne Muscular Dystrophy is caused by which mode of inheritance?

Autosomal X-linked recessive


What are the main considerations when treating a child?

  • Children are not small adults.
  • They have unique physiology and different age ranges have different parameters. 
    • Therefore, drug concentrations must be calculated per kg until the child is old enough.
  • With respect to congenital problems - congenital disorders may take years to present. 
  • You can get A LOT of information from observing the child:
    • What do they do?
    • What don't they do that you might expect them to?


Which genetic defect causes Duchenne Muscular Dystrophy?

  • DMD is caused by a defect in Xp21 Dystrophin gene. 
  • P = short arm of the chromosome. 


What is the disease process in a child with Duchenne Muscular Dystrophy?

  • Destruction of skeletal muscle leading to progressive weakness.
  • Pseudo-hypertrophy of the lower limb muscles - they look big but are actually being replaced with adipose tissue. 
  • Muscle wastage is progressive. Patients usually in wheelchair by early teens and death usually in 30s. 
  • The Dystrophin gene produces a protein that protects the mitochondria in the muscle. These mitochondria are destroyed in DMD so the muscles are subject to atrophy.


Describe the presentation of a child with Duchenne Muscular Dystrophy.

  • Positive Gower's sign - typically presents with gross motor delay. 
  • Probably a delay in milestones - walking and hopping etc.
    • Not walking by 18 months is a huge red flag in any child.
  • Pseudo-hypertrophy of the lower limb muscles - look big but are actually being replaced by adipose tissue. 
  • Speech - in clinic they can be nervous so ask parents how the speech is at home. 


What are the diagnostic tools used to identify Duchenne Muscular Dystrophy?

  • Muscle cell biopsy will show changes in the muscle which can be useful for diagnosis. 
  • Ck (creatine kinase) is massively elevated in a child with DMD; this can be tested for in the blood. 
  • Definitive diagnosis comes from genetic testing. 


What are the treatments for a patient with Duchenne muscular dystrophy?

  • The main treatment is exercise - physiotherapy to keep the muscles active. 
  • Steroids have been shown to help maintain muscle strength and prolong the period children can walk and stay healthy.
  • BUT, the suppression of the normal steriod system in the body (controls immune system, puberty) causes problems. 
    • Steroids need to be increased and sometimes testosterone must also be given.
  • Gene / stem cell therapy will play a larger part in future.