The muscular dystrophies, amyotrophic lateral sclerosis, myasthenia gravis, and other inherited and acquired diseases cause muscle degeneration. The symptoms of degenerative muscle diseases relate to progressive weakness in the affected muscle groups.verview. Degenerative muscle diseases cause progressive damage and loss of muscle cells with associated weakness. There are many types of degenerative muscle diseases, and they act in different ways to cause loss of functional muscle mass.