Glycerol‐3‐phosphate excretion in fructose‐1,6‐diphosphatase deficiency

Abstract

A patient aged 23 months with fructose-1,6-diphosphatase deficiency is reported. This infant demonstrated an increased urine excretion of glycerol-3-phosphate during episodes of hypoglycaemia. The excretion of this compound has not previously been described in this disease or in those disorders associated with a deficiency in one of the other three gluconeogenic enzymes associated with hypoglycaemia. Its presence in the urine from patients may be useful in diagnosis.

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.…”

A Japanese boy with fructose-1,6-bisphosphatase deficiency who had a novel <i>FBP1</i> mutation (p.Phe90Val)

“…In general, urinary organic acid analysis using gas chromatography-mass spectroscopy (GC/MS) is very useful for screening FBPase deficiency ( 5 ). The fructose tolerance test from our patient showed a high level of glycerol excretion in the urine, whereas the excretion of glycerol-3-phosphate was at a normal level.…”

“…Since the first identified mutations in 1995, at least 36 additional mutations resulting in FBPase deficiency, including those from the Japanese population ( 4 ), have been described in the genomic region spanned by FBP1 . Excretion of glycerol and glycerol-3-phosphate in the urine may help to distinguish this disease from other metabolic acidosis diseases ( 5 ). Here, we report a patient with FBPase deficiency caused by novel compound heterozygous mutations in FBP1 , who had normal urine glycerol-3-phosphate during an oral fructose tolerance test.…”

Fructose‐1,6‐bisphosphatase deficiency: Severe phenotype with normal leukocyte enzyme activity

“…It may present in the neonatal period with severe life-threatening episodes, with patients exhibiting hyperventilation, hypotonia, convulsions and hepatomegaly with fatty infiltration. Hypoglycaemia, lactic acidosis, ketosis and hyperalaninaemia are commonly found and increased concentrations of glycerol (Dremsek et al 1985), glycerol-3-phosphate (Krywawych et al 1986) and other sugar phosphates (Nakai et al 1993) are characteristic features.…”