A diagnostic protocol for adult-onset glycogen storage disease type II

To analyze the diagnostic value of various laboratory tests for the confirm ation of adult-onset glycogen storage disease type II (GSD II), we performe d a clinical, biochemical, and genetic study of 18 patients with this disea se. Measurement of acid alpha-glucosidase (GAA) activity in muscle and hist opathologic analysis of muscle tissue appeared to have no additional value when GAA activity in leukocytes was clearly deficient. Our study showed tha t creatine kinase elevation is a sensitive marker of GSD II. A diagnostic p rotocol is formulated.