Differential Diagnosis for Fasting Hypoglycemia in an Infant with Hypertriglyceridemia and Lactic Acidosis
- The combination of fasting hypoglycemia, hypertriglyceridemia, and lactic acidosis in an infant suggests a defect in fatty acid oxidation or glucose metabolism.
Single Most Likely Diagnosis
- Glucose-6-phosphatase deficiency (Von Gierke's disease): This condition is characterized by fasting hypoglycemia, lactic acidosis, and hypertriglyceridemia due to the inability to convert glucose-6-phosphate to glucose, leading to an accumulation of glucose-6-phosphate and subsequent increase in glycolysis, resulting in lactic acidosis and hypertriglyceridemia.
Other Likely Diagnoses
- Carnacitine Palmitoyltransferase (CPT) deficiency: A defect in fatty acid oxidation, leading to an accumulation of long-chain fatty acids and their metabolites, resulting in hypertriglyceridemia and lactic acidosis.
- Pyruvate Dehydrogenase Complex (PDH) deficiency: A defect in the conversion of pyruvate to acetyl-CoA, leading to an accumulation of pyruvate and subsequent increase in lactic acidosis.
- Fatty Acid Oxidation defects (e.g., Medium-Chain Acyl-CoA Dehydrogenase (MCAD) deficiency): Defects in the breakdown of fatty acids, leading to an accumulation of toxic metabolites and resulting in hypertriglyceridemia and lactic acidosis.
Do Not Miss Diagnoses
- Glycogen storage disease type III (Cori's disease): A defect in the debranching enzyme, leading to an accumulation of abnormal glycogen and resulting in fasting hypoglycemia, lactic acidosis, and hypertriglyceridemia.
- Mitochondrial disorders (e.g., Kearns-Sayre syndrome): A group of disorders affecting the mitochondria, leading to impaired energy production and resulting in lactic acidosis, hypertriglyceridemia, and fasting hypoglycemia.
Rare Diagnoses
- Phosphorioaminotransferase deficiency: A rare defect in the purine nucleotide cycle, leading to an accumulation of toxic metabolites and resulting in hypertriglyceridemia and lactic acidosis.
- Fructose-1,6-bisphosphatase deficiency: A rare defect in gluconeogenesis, leading to an accumulation of fructose-1,6-bisphosphate and resulting in fasting hypoglycemia, lactic acidosis, and hypertriglyceridemia.