Muscular Dystrophy (3)

Question 1

What is this?

What is the most common type?

What is the 2nd most common type?

What’s the pathophysiology behind both of these?

Answer 1

➊ Genetic conditions that cause gradual weakening and wasting of muscles

➋ Duchenne’s

➌ Becker’s (milder version of duchenne’s)

➍ Both X-linked recessive disorders causing mutations in expression of Dystrophin, which is a protein involved in muscle contraction

Question 2

Duchenne’s Muscular Dystrophy:
What occurs here?

How does it present?

What sign is seen here?
→ What does it look like?

Answer 2

➊ No expression of Dystrophin

➋ • Usually wheelchair-bound before puberty and die from respiratory failure in early 20s
• Bulky-muscles (particularly calves), as degenerated muscle is replaced by fat
• Proximal muscle weakness

➌ Gower’s Sign - Indicates proximal muscle weakness
→ Child walk their arms up their legs to get up from the floor

Question 3

Becker’s Muscular Dystrophy:
What occurs here?

How does it present?

Answer 3

➊ Little expression of Dystrophin

➋ Same as DMD, but presents later in childhood, with a longer survival time

Question 4

Which investigations are done?

Answer 4

• Genetic testing
• CK – Good screening test and way of monitoring disease progression