The symptomatology, morphology and biochemistry of glycogenosis type II (Pompe) in the adult.

The mild, generalized myopathy (glycogenosis type II) of a 23-year-old male, previously thought to have progressive muscular dystrophy, was studied clinically, electro-myographically, biochemically and with light- and electron microscopes. However, the history and clinical aspects, as well as the registration of high frequency discharges in the electromyogram first made the diagnosis uncertain. This kind of spontaneous activity has been found in nearly all cases reported in the literature. Light microscopic and histochemical examinations show vacular degeneration and glycogen storage in muscle fibres. With the electron microscope we found free dispersed glycogen in the cytoplasm and membrane-bound glycogen, glycogen-filled lysosomes. Biochemical measurements of the muscle enzymes, involved in the glycogen breakdown, were normal except for acid alpha-1,4-glucosidase, which was deficient. The evidence of these findings in this abortive form of glycogenosis type II is discussed and compared with the few cases found in the literature.