Studies on the structure and metabolism of glycogen in some abnormal human infants.

1. The liver and muscle tissues of 14 human anencephalic babies were examined for glycogen content and structure, and for the activities of several glycogen-metabolizing enzymes. 2. In both tissues glycogen content increased with gestation age; the muscle glycogens had a slightly but significantly lower degree of branching than the corresponding liver glycogens. 3. All the expected glycogen-metabolizing enzymes were present; acid maltase activities were higher and phosphoglucomutase activities were lower than the results reported for human adult tissues. Glucose 6-phosphatase activity increased significantly with gestation age.