Question

Dystrophin is a rod-shaped cytoplasmic protein located beneath the sarcolemma (plasma membrane). It links actin filaments of the outmost layer of the myofilaments to the inner surface of the plasma membrane (sarcolemma). It interacts with many other muscle proteins and forms a dystrophin-associated protein complex that links cytoplasmic proteins with extracellular structural proteins. Which condition is characterized by progressive degeneration of muscles, particularly those of the pelvic and shoulder girdles?

1) Duchenne muscular dystrophy
2) Myotonic dystrophy
3) Becker muscular dystrophy
4) Limb-girdle muscular dystrophy

Answer 1

Duchenne muscular dystrophy (DMD) is the condition characterized by the progressive weakening of muscles, especially in the pelvic and shoulder girdles, due to a lack of the critical protein dystrophin.

Step-by-step explanation:

The condition characterized by progressive degeneration of muscles, particularly those of the pelvic and shoulder girdles, is known as Duchenne muscular dystrophy (DMD). DMD is a genetic disorder resulting from a deficiency of the protein dystrophin, which is critical for muscle function. Without adequate dystrophin, muscles suffer cellular damage and progressive weakening due to ineffective connection between actin filaments and the sarcolemma during muscle contraction. This leads to an increase in calcium influx, causing additional damage and ultimately muscle tissue death. Despite efforts, including the potential use of healthy myoblasts or boosting utrophin production, effective treatments for reversing the damage caused by DMD remain elusive.