Fig. 1.

(a, b) There was mild vacuolar myopathy of smooth muscle (*) and moderate vacuolar myopathy of skeletal muscle (**) in the mid esophagus of patient 1 (hematoxylin and eosin; magnification bars = 500 μm in a and 100 μm in (b). (c, d) The sinoatrial node (*) of patient 1 had severe vacuolation of the specialized myocytes comprising this structure, along with severe vacuolar myopathy of the right atrial cardiac myocytes (hematoxylin and eosin, magnification bars = 500 μm in c and 50 μm in d). (e, f) Smooth muscle cells and some neurons within ganglia of the myenteric plexus (*; Auerbach’s plexus) of the small intestine of patient 2 were laden with glycogen (e: periodic acid-Schiff stain and f: periodic acid-Schiff stain after diastase digestion of glycogen; magnification bar = 50 μm). (g, h) Anterior horn neurons (*) of the spinal cord of patient 2 exhibited prominent glycogen accumulation (a: periodic acid-Schiff stain and b: periodic acid-Schiff stain after diastase digestion of glycogen; magnification bar = 50 μm for both g and h). (i, j) The bundle of His (*) in patient 3 had moderate vacuolation of its specialized myocytes (hematoxylin and eosin; magnification bars = 100 μm in I and 50 μm in j)