Muscular dystrophy Flashcards
What is muscular dystrophy?
An umbrella term for genetic conditions that cause gradual weakening and wasting of muscles
What are the main types of muscular dystrophy?
- Duchennes muscular dystrophy
- Beckers muscular dystrophy
- Myotonic dystrophy
What type of inheritance does Duchennes muscular dystrophy have?
X-linked recessive
What is Duchenne’s caused by?
A defective gene for dystrophin on the X-chromosome
What is dystrophin?
A protein that helps hold muscles together at the cellular level.
What are the main features of Duchenne’s muscular dystophy?
- progressive proximal muscle weakness from 5 years
- calf pseudohypertrophy
- myotonia- sustained muscle contraction
- Gower’s sign
What is gowers sign?
Child uses arms to stand up from a squatted position
What do 30% of people with muscular dystrophy have?
Intellectual impairment
When do boys with duchenne’s tend to first present?
3-5 years
What do boys with Duchenne’s first present with?
Weakness in the muscles around their pelvis
What is the main investigation for Duchenne’s?
Creatinine Kinase
What level will the creatinine kinase be in Duchenne’s?
The creatinine kinase will be excessively raised
What is the definitive diagnosis of Duchenne’s?
Genetic testing
Is there a cure for Duchenne’s?
No
Supportive management
What can be used to slow the progression of muscle weakness?
Oral steroids
What can be given to slightly improve muscle strength?
Creatinine supplementation
By what age are boys with Duchenne’s usually unable to walk?
12 years old
What is the life expectancy for someone with Duchenne’s?
25 – 35 years
What cardiac condition is Duchenne’s associated with?
Dilated cardiomyopathy
What is Becker’s muscular dystrophy?
Very similar to Duchennes, however the dystrophin gene is less severely affected and maintains some of its function.
What is the problem with Becker’s muscular dystrophy?
The clinical course is less predictable
When do symptoms of Becker’s muscular dystrophy appear?
Around 8 – 12 years.
What is the management of Becker’s muscular dystrophy?
Same as Duchenne’s Muscular Dystrophy