Skeletal muscle comprises more than 40% of our body weight and is essential for support, physical movement, protection of internal organs, breathing and metabolism. Muscular dystrophies are genetically inherited diseases characterized by progressive wasting of muscle.
We focus on two genetic muscle disorders:
Duchenne muscular dystrophy (DMD)
Is a devastating muscle wasting disease caused by out-of-frame mutations in the DMD gene, which occurs in 1:5,000 male births. DMD codes for dystrophin, a protein that supports muscle fiber strength, and loss of dystrophin expression causes membrane instability of the muscle fibers. As a result, muscle tissue is lost and patients become wheelchair dependent, lose the ability to use their hands and arms and ultimately die due to respiratory or cardiac failure in their early to mid-twenties.
Facioscapulohumeral muscular dystrophy (FSHD)
Is an autosomal dominant gain of function disease, often affecting young adults before they are 20 years of age. FSHD affects mainly the upper body, including the face, shoulder blades and arms. Although the molecular pathophysiology of FSHD is complex and not well understood, abnormal activation of the DUX4 gene is a causative factor triggering muscle fiber decay in these patients.