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Two cases of phosphoenolpyruvate carboxykinase deficiency
Insights
A rare genetic disorder caused hypoglycemia and liver issues in two children due to a deficiency in phosphoenolpyruvate carboxykinase, a key gluconeogenesis enzyme. This deficiency led to fat accumulation in vital organs.
Area of Science:
- Biochemistry
- Pediatric Medicine
- Genetics
Background:
- Hypoglycemia and liver impairment can arise from various metabolic disorders.
- Gluconeogenesis is a critical pathway for maintaining blood glucose levels, particularly between meals.
Observation:
- Two pediatric cases presented with severe hypoglycemia and significant liver dysfunction.
- Post-mortem analysis revealed massive steatosis (fat deposition) in the liver and kidneys.
Findings:
- Enzyme assays on liver tissue identified a deficiency in phosphoenolpyruvate carboxykinase (PEPCK).
- PEPCK is a crucial enzyme in the gluconeogenesis pathway, responsible for converting oxaloacetate to phosphoenolpyruvate.
Implications:
- The PEPCK deficiency directly explains the impaired gluconeogenesis and subsequent hypoglycemia.
- Altered mitochondrial-cytosolic metabolic flux due to PEPCK absence likely underlies the observed hepatic and renal steatosis.
- This highlights PEPCK deficiency as a cause of inherited metabolic disease presenting with hypoglycemia and fatty liver.
Abstract:
Two children are described who suffered from hypoglycemia and liver impairment. Assays of gluconeogenic enzymes in liver samples taken immediately after death demonstrated a deficiency of phosphoenolpyruvate carboxykinase, a key enzyme of gluconeogenesis. Post mortem examination demonstrated massive fat deposition in liver and kidney and to a lesser extent in other tissues. The fatty changes in liver and kidney could be explained by the absence of phosphoenolpyruvate carboxykinase, which would cause an alteration in the mitochondrial-cytosolic processes related to gluconeogenesis.