Clinical and pathological features of 20 patients of glycogen storage disease type II

Abstract

Objective To summarize the clinical and pathological features of glycogen storage disease (GSD) type Ⅱ. Methods The clinical and pathological data of the 20 GSD type Ⅱ patients were reviewed. Results One patient with infantile-onset mainly presented hypotonia, muscle weakness, feeding difficulties, pulmonary infection and cardiomyopathy insufficiency and increase of serum creatine kinase (778 IU/L) and echographic evidence of hypertrophic cardiomyopathy were detected. Electromyography studies indicated a definite myopathy. Nineteen cases were late-onset, presenting a slowly progressive proximal myopathy with truncal involvement or with symptoms dominated by respiratory insufficiency. Not all muscles were equally affected. Increase of serum creatine kinase (208-2600 IU/L) was detected in 14 patients and normal level in 1 patient. Electromyography studies indicated a definite myopathy in 9 patients,with abnormal irritability in 1 patient and susceptible in 4 patients and myotonic discharge in 1 patient and no abnormalities in 2 patients. Echographic evidence of thickening of the interventricular septum and pulmonary hypertension were detected in 2 patients respectively. The common light microscopic feature of all case was a vacuolar myopathy with high glycogen content and acid phosphatase activity in the vacuoles. Conclusions GSD type Ⅱ often presents slowly progressive myopathy which often affect the toro and respiratory muscles.In most patients the serum creatine kinase level is elevated slightly. Muscle biopsy is of use to make the definite diagnosis of this disease. Key words: Glycogen storage disease type Ⅱ ; Vacuoles ; Muscle ; Biopsy ;