Muscular Dystrophies

Question 1

what is the pathogenesis?

Answer 1

progressive muscle weakness and wasting changes in muscle itself - but not the nerve or NMJ

Question 2

what are dystrophinopathies

Answer 2

mutations on the dystrophin gene - Duchenne, Becker

Question 3

what are other muscular dystrophies which don’t have dystrophin mutation?

Answer 3

other proteins whih complex with dystrophin protein - similar symptoms to dystrophinopathies

Question 4

what happens if there is no dystrophin?

Answer 4

sarcolemma becomes unstable cellular proteins start escaping the damaged cell and Ca2+ enters the cell this leads to cell death short term - muscle regeneration - muscle fibres of different sizes long term - muscle atrophy - fat and fibrotic tissue innervation - weak muscles - noticeable in legs

Question 5

who gets it?

Answer 5

usually X-linked recessive hereditary (only boys) - 1 copy of the dystrophin genes for boys, although women can be manifesting/non-manifesting carriers sporadic mutation also possible