An Iranian Patient with Fructose 1,6 Bisphosphatase Deficiency: A Case Report

Deficiency of hepatic fructose 1,6 bisphosphatase (FBPase), a key enzyme in gluconeogenesis, impairs the formation of glucose from all gluconeogenic precursors including dietary fructose. Patients present with life threatening metabolic acidosis, fasting hypoglycemia, hepatomegaly, hyperketosis, elevated lactate and uric acid level. Glycerol and glycerol-3 phosphate have been found in the urine. The diagnosis of FBPase deficiency is confirmed via DNA molecular analysis from peripheral leukocytes. The acute life threatening episodes are treated with IV glucose at high rate and bicarbonate to control hypoglycemia and acidosis.

Here we report a girl referred with anorexia, lethargy, recurrent vomiting, progressive respiratory distress, and hepatomegaly following respiratory viral infection. She also had a history of twice similar attacks but milder than previous episodes. The test results showed hypoglycemia and severe metabolic acidosis. Despite proper treatment, the patient died of pulmonary edema following a respiratory viral infection.

Once FBPase deficiency has been diagnosed and adequate management introduced, its course is usually benign. Growth both psychomotor and intellectual development are unimpaired and tolerance to fasting improves with age.