[Myopathy caused by acid maltase deficiency in an adult].

We report a 46 years old male presenting with tetraparesis and severe respiratory involvement. He had moderately elevated serum creatine phosphokinase values and the electromyography showed myopathic alterations and irritative signs. In the muscle biopsy, a vacuolar myopathy with increased collagen deposits was found. Circulating lymphocytes presented abnormal PAS positive granules in their cytoplasm.