Final answer:
Dystrophin is essential for stabilizing and protecting muscle fibers and in X-linked recessive disorders like Duchenne Muscular Dystrophy (DMD), the lack of dystrophin due to a genetic mutation leads to progressive muscle degradation, resulting in severe muscle weakness, loss of mobility, and reduced lifespan.
Step-by-step explanation:
Dystrophin is a protein that plays a crucial role in muscle function. In X-linked recessive disorders such as Duchenne Muscular Dystrophy (DMD), there is a mutation in the gene that codes for dystrophin, resulting in a lack or insufficiency of this protein. Dystrophin helps to stabilize and protect muscle fibers during contraction by connecting the cytoskeleton of each muscle fiber to the extracellular matrix. Without sufficient levels of dystrophin, the sarcolemma (the muscle cell membrane) is prone to damage during muscle contraction. This leads to an influx of calcium (Ca++), which causes cellular damage and muscle fiber degradation. Over time, this contributes to progressive muscle weakness, and a decline in muscle mass and function typical of DMD, with symptoms including difficulty with balance and motion, and eventually leading to loss of the ability to walk.
DMD is an inherited disorder that primarily affects males due to its X-linked pattern of inheritance. Affected individuals often show initial signs in early childhood and can experience severe muscle degeneration that progresses to vital muscles, such as those responsible for breathing and circulation, eventually leading to premature death. While some treatments attempt to compensate for the lack of dystrophin by introducing healthy myoblasts or boosting the production of utrophin, a dystrophin-like protein, these have been largely unsuccessful. The progression of DMD commonly leads to the need for assistive devices for mobility and, over time, respiratory support.