Muscular Dystrophy

Question 1

Wht factors determine muscle repair ability

Answer 1

IGF-1, testosterone and other growth hormones, they will ddecline as we get older,

Question 2

What are the symptoms of muscular dystrophy

Answer 2

Generalised wasting and weakness, enlarged calves and it is a progressive disorder that affects respiratory muscles the last

Question 3

Genetic statistics of MD

Answer 3

1 in 6000 and 1 in 3 cases are spontaneous,

Question 4

Progression of MD

Answer 4

Onset at 2-6 years, by 3-6 the gait will be affected, by 7-13 will become wheelchair dependent. At the age of 20 must go on a ventilator as they go into respiratory failure as diaphragm is affected

Question 5

What gene is mutated

Answer 5

The Dystrophin gene

Question 6

What is the function of the Dystrophin gene

Answer 6

Will connect the sarcoplasmic reticulum membrane to the basal laminar to have a basement for attachment and hence allows contraction

Question 7

What is a consequence of dystrophin absence

Answer 7

In the absence of dystrophin, the muscles will waste. Due to the force applied during contraction, membranes become weak and fragile. Ca2+ will promote necrosis of the muscle cells. Muscle will then repair themselves. However this cannot be sustained and over time muscles will waste and be replaced by fat

Question 8

What is Becker’s MD

Answer 8

Is a less severe form of DMD, the mutation in Dystrophin is not as severe, as part of the protein is expressed and can underatke some function

Question 9

What are some therapies to treat MD

Answer 9

Corticosteriod therpay which has increased lifespan by around 10 years, also anabolic steriods, IGF-1, GH and myostatin inhibitors and calcium channel blockers

Question 10

What is BPG-15

Answer 10

It is a peptide drug that will increase the levels of HSP72 in the muscle cells. Will reduce Fibrosis and CT within the the muscle. Will delay the onset of ventillator