Enzyme deficiency | Lactic acid | Uric acid | Ketosis | Serum lipids | Response to glucagon | Clinical features |
Glycogen synthase (GSD 0) | ↑* | ↑ | + | ↑ | ↓ | Normal liver size |
Neonatal onset |
Severe fasting hypoglycemia, but postprandial hyperglycemia and lactic acidosis |
Glucose-6-phosphatase (GSD I) | ↑ | ↑ | + | ↑ | ↓ | Hepatomegaly |
Neonatal onset |
Severe fasting hypoglycemia |
Some patients have neutropenia, platelet dysfunction, kidney disease, or hypertension |
Glycogen debrancher (GSD III) | Normal or ↑ | Normal | + | Normal or ↑ | Normal 2 hours after glucose meal, but absent after fast | Hepatomegaly |
Onset in infancy |
Mild fasting hypoglycemia |
May have cardiac or skeletal muscle manifestations (eg, elevated CK) |
May have elevated RBC glycogen |
Hepatic phosphorylase (GSD VI) | Normal | Normal | + | Normal or ↑ | Usually normal, but variable | Hepatomegaly |
Onset in early childhood |
Mild fasting hypoglycemia |
Hepatic phosphorylase b kinase | Normal | Normal or ↑ | + | Normal or ↑ | Normal | Hepatomegaly |
Onset in early childhood |
Mild fasting hypoglycemia |
X-linked inheritance |