[Determination of blood level of muscle enzymes in glycogenoses with liver involvement: a diagnostic criterion].

Serum muscle enzyme activity assays were routinely performed in 36 patients with glycogen storage diseases (15 types 1a and 1b, 12 type III, and 9 types VI and IX). Creatine phosphokinase serum activity was increased only in type III. Glutamate-pyruvate transaminase, aldolase and lactate dehydrogenase serum activities were increased in all the forms of glycogen storage disease studied. Muscle involvement may at least partly explain the increased serum enzyme activities in type III.