Dystrophinopathies

Question 1

inheritance

Answer 1

X linked recessiev

Question 2

genetic cause

Answer 2

mutation in the gene encoding dystrophin

(Xp21)

Question 3

Role of dystrophin

Answer 3

part of a large membrane associated protein

• helps connects the muscle membrane to actin (muscle cytoskeleton)

Question 4

Examples of muscular dystrophy

Answer 4

Duchenne
Becker

Question 5

Clinical features of duchenne muscular dystrophy

Answer 5

• progressive proximal muscle weakness from 5y
• calf pseudohypertrophy
• Gower’s sign: child uses arms to stand up from a squatted position
• 30% = intellectual impairment

Question 6

Clinical features of Becker muscular dystrophy

Answer 6

• develops after the age of 10
• intellectual impairment less common