[Clinical and pathological features of glycogen storage disease type III]

To summarize the clinical and pathological features of glycogen storage disease (GSD) type III.

The clinical data of 12 GSD type III, 8 males and 4 females, aged 2 - 27, were collected. The biopsy specimens of quadriceps muscle of thigh underwent HE and histochemical staining and light and electron microscopy.

The main clinical feature were hepatomegaly and hypoglycemic symptoms, slow growth, and microsome since childhood, while myopathy was mild. Laboratory findings included low plasma glucose (n = 12), high liver transaminases (n = 12), increased CK (n = 11), mild metabolic acidosis (n = 11), hyperlipemia (n = 9), elevation of blood lactate (n = 5), high uric acid (n = 1), and decrease of serum carnitine level (n = 1). One patient had echographic evidence of cardiomyopathy. 11 patients were postprandial adrenalin stimulation test positive. Raw corn starch therapy was used on all patients and showed effective on liver manifestations. Muscle biopsy showed vacuolar myopathy, PAS positive glycogen granules in muscle fibers, small foci of intense ACP reactivity, and deposit of lipid droplets.

GSD type III exhibits a clinical heterogeneity. Besides hepatic symptoms, myopathy and cardiomyopathy should be addressed adequately. The degree of pathological change of muscles is not significantly related to the degree of functional impairment, duration of disease, and level of CK.