Fructose-1,6-diphosphatase deficiency: glycerol excretion during fasting test

Abstract

A Turkish boy had suffered since the age of 10 months from recurrent attacks of severe metabolic acidosis and hypoglycaemia precipitated by moderate respiratory tract infections. A liver biopsy showed lack of fructose 1,6-diphosphatase and absence of phosphorylase. The patient died in shock following fructose ingestion. Upon fasting, acidosis with increased lactate and glycerol excretion was found. Findings indicate that, in this inherited disorder of gluconeogenesis, lactic acidosis combined with increased glycerol excretion upon fasting are of diagnostic importance.

Clinical and biochemical observations on three cases of fructose‐1,6‐diphosphatase deficiency

“…Our data, together with other reports (Dremsek et al, 1985;Krywawych et al, 1986), indicate that urinary organic acid analysis should be performed in patients with hypoglycaemia and lactic acidosis, not only to exclude amino acid defects, but also to identify disorders of gluconeogenesis because glycerol excretion on fasting or during acidosis is of diagnostic importance in FDPase deficiency. Finally, the use of fructose-free food and avoidance of prolonged fasting with administration of uncooked corn starch (2 g/kg) mixed with water at midnight were of benefit to our patients, preventing nocturnal hypoglycaemia and improving their clinical response to illness.…”

Fructose-1,6-bisphosphatase deficiency as a cause of recurrent hypoglycemia and metabolic acidosis: Clinical and molecular findings in Malaysian patients

“…1,2 FBPase deficiency may be suspected by detecting elevated urinary excretion of glycerol or glycerol-3-phosphate. 3,4 Direct enzymatic assay of hepatic FBPase activity remains the most specific diagnostic test for FBPase deficiency, but this is only performed by a handful of reference laboratories. Molecular study is increasingly performed to confirm the diagnosis.…”

Pitfall in the Diagnosis of Fructose-1,6-Bisphosphatase Deficiency: Difficulty in Detecting Glycerol-3-Phosphate with Solvent Extraction in Urinary GC/MS Analysis

“…Fasting and febrile episodes are known to trigger these symptoms during infancy and childhood. Gas chromatography-mass spectrometry (GC/MS) analysis of urinary organic acids during a spell can be especially helpful when diagnosing FBPase deficiency, because the appearance of glycerol or glycerol-3-phosphate in the urine is characteristic of this disease (Dremsek et al 1985;Burlina et al 1990;Nakai et al 1993). For this method, organic solvent extraction is usually employed for the pretreatment of samples, because target substances such as organic acids are easily collected and contamination of GC column can be prevented (Kimura et al 1999).…”