Table 6.
Main clinical and biochemical features of major metabolic causes of childhood HY.
| Disorder | Timing | Lactate | Ketones | Additional biochemical abnormalities | Clinical features |
|---|---|---|---|---|---|
| Ketotic hypoglycemia | Fasting >6 h | +/− | + | Low alanine | Fever |
| M.A. | Vomiting | ||||
| Diarrhea | |||||
| Glycogen storage disease type I | Fasting (2–4 h) | + | (−) | Elevated lipids | Hepatomegaly |
| M.A. | Elevated uric acid | Doll–like face | |||
| Elevated transaminases | |||||
| Neutropenia (GSDIb) | |||||
| Glycogen storage disease type III/VI/IX | Fasting (2–6 h) | − | + | Elevated lipids | Hepatomegaly |
| Elevated transaminases | Cardiomyopathy | ||||
| Elevated CK (GSDIIIa) | (GSDIIIa) | ||||
| Hereditary Fructose Intolerance | 1–2 h after the ingestion of fructose, sucrose, sorbitol | + | +/− | Elevated transaminases | Vomiting |
| M.A. | Diarrhea | ||||
| Hepatomegaly | |||||
| Liver failure | |||||
| Fatty liver | |||||
| Galactosemia | 1–2 h after the ingestion of galactose, lactose | − | +/− | Elevated bilirubin | Vomiting |
| M.A. | Elevated transaminases | Hepatomegaly | |||
| Abnormal clotting tests | Liver failure | ||||
| Cataract | |||||
| Sepsis | |||||
| Fructose 1,6 bisphosphatase deficiency | Fasting >6 h | + | + | Elevated alanine | Intercurrent disease |
| M.A. | Elevated pyruvate and glycerol 3–phosphate | Hepatomegaly | |||
| Pyruvate carboxylase deficiency | Variable | + | + | Hyperammonemia | Severe encephalopathy |
| M.A. | Elevated citrulline | Seizures | |||
| Movement disorders | |||||
| Organic acidemias | Prolonged fasting or after an initial symptom–free period (neonatal) | + | + | Hyperammonemia | Encephalopathy |
| M.A. | Elevated branched chain amino acids and glycine | Movement disorders | |||
| Elevated acylcarnitines | Renal disease | ||||
| UOA abnormalities | Cardiomyopathy | ||||
| Fatty acid oxidation disorders | Fasting >8 h | + | (−) | Elevated acylcarnitines | Exercise intolerance |
| M.A. | FFA/KB > 2.5 | Dicarboxylic aciduria | Cardiomyopathy | ||
| Hyperammonemia | Arrhythmias | ||||
| Ketogenesis defects | Prolonged fasting or after an initial symptom–free period (neonatal) | + | − | Hyperammonemia | Hepatomegaly |
| M.A. | FFA/KB > 2.5 | Dicarboxylic aciduria | Seizures | ||
| UOA abnormalities | Cardiomyopathy | ||||
| Ketolysis defects | Prolonged fasting | − | + | UOA abnormalities | Intercurrent disease |
| FFA/KB < 0.3 | Hepatomegaly | ||||
| Disorders of Oxidative Phosphorylation | Variable | + | +/− | UOA abnormalities | Multisystem |
| M.A. | involvement | ||||
| Congenital Disorders of Glycosylation | Variable | +/− | +/− | High insulin (mostly) | Psychomotor retardation |
| Dysmorphic features | |||||
| Multisystem involvement |
M.A., metabolic acidosis.