Protein Abnormalities in Neuromuscular Diseases—Part 2

Abstract
Tissue Protein Deficiency Phosphorylase in Muscle Phosphorylase Deficiency Dr. Engel: The first example of tissue protein deficiency is illustrated by a 52-year-old woman who had progressive muscle weakness and wasting in the proximal-limb and trunk regions from age 48, but she was apparently quite normal up to that time (Fig 12). Clinical and laboratory studies indicated that she had a disease of muscle, that is, a myopathy. Known causes of myopathy beginning in her age group, such as collagen-vascular disease and distant neoplasia, could not be found by careful studies. At that point the diagnosis appeared to be the most common one in female patients of her age group—namely, late-onset myopathy, cause unknown. The muscle biopsy confirmed that there was a myopathy, evidenced by disruption of the internal architecture of the muscle fibers and increased connective tissue around individual muscle fibers. However, an additional finding turned up. Routine histochemistry revealed