Gluconeogenesis defect presenting with resistant hyperglycemia and acidosis mimicking diabetic ketoacidosis.

Fructose-1,6-diphosphatase (FDPase) enzyme deficiency is a rare inherited metabolic disease. Affected patients usually present with metabolic crisis including hypoglycemia, acidosis, ketonuria, and hyperuricemia. A previously healthy 8-month-old male infant presented with fever, vomiting, and hypoactivity. He had tachycardia, tachypnea, and a tendency to sleep. The patient had signs of severe dehydration and shock. Laboratory findings revealed significant lactic acidosis, hyperuricemia, hyperglycemia, elevated liver enzyme level, and hyperlipidemia. The urine analysis had evidence of glycosuria and ketonuria. Hyperuricemia, lactic acidemia, and hyperglycemia persisted despite insulin infusion, adequate hydration, and perfusion. Consequently, peritoneal dialysis was started. About 12 hours after dialysis, his metabolic derangements were normalized, and clinical status was improved dramatically. His metabolic disease workup was compatible with FDPase deficiency. Here, we described a metabolic attack of FDPase deficiency presented with hyperglycemia mimicking diabetic ketoacidosis.