Hereditary fructose intolerance mimicking a biochemical phenotype of mucolipidosis: A review of the literature of secondary causes of lysosomal enzyme activity elevation in serum

We describe a patient with failure to thrive, hepatomegaly, liver dysfunction, and elevation of multiple plasma lysosomal enzyme activities mimicking mucolipidosis II or III, in whom a diagnosis of hereditary fructose intolerance (HFI) was ultimately obtained. She presented before introduction of solid foods, given her consumption of a fructose-containing infant formula. We present the most extensive panel of lysosomal enzyme activities reported to date in a patient with HFI, and propose that multiple enzyme elevations in plasma, especially when in conjunction with a normal plasma α-mannosidase activity, should elicit a differential diagnosis of HFI. We also performed a review of the literature on the different etiologies of elevated lysosomal enzyme activities in serum or plasma. © 2016 Wiley Periodicals, Inc.

Clinical and genetic analysis for a Chinese family with hereditary fructose intolerance

Hereditary fructose intolerance (HFI) is an inheritable disorder of fructose metabolism, inherited as an autosomal recessive disorder and caused by catalytic deficiency of aldolase B, which is critical for gluconeogenesis and fructose metabolism. The affected individuals develop severe hypoglycemia after taking foods containing fructose and cognate sugars. The exons 2-9 of the aldolase B (gene symbol ALDOB) gene from one Chinese HFI patient were amplified by the polymerase chain reaction (PCR), and direct sequence determination was applied to the amplified fragments. The mutation of a 4-bp (AACA) deletion (479_482 del) in exon 4 of ALDOB gene was identified in the patient, which had been reported to cause a frameshift at codon 118 and a truncated protein of 132 amino acids in the previous study. Then, the second case with the same homozygote deletion and eight cases with heterozygotes had been found through screening for the mutation c.479_482 del AACA in the whole family. This is the first report of HFI with the mutation c.479_482 del AACA in the ALDOB gene in a Chinese family.

[Metabolic changes in patients with hereditary fructose intolerance. A contribution to the topic of fructose administration for parenteral feeding]

The literature contains a number of reports of death following the intravenous administration of fructose in patients with hereditary fructose intolerance (HFI). The aim of the present study was, therefore, to investigate the metabolic changes occurring during intravenous administration of fructose to patients with HFI, with the aim of identifying metabolic parameters that would permit the early diagnosis of HFI. Also, the deaths reported in the literature were analyzed. In three of our own patients with fruit intolerance known since childhood, and in volunteers with normal metabolism, a one-hour intravenous fructose tolerance test (1.7 g fructose/min) was performed. An analysis was done using the usual enzymatic and chemical methods: blood glucose, fructose, lactic acid, serum uric acid, ammonia, free fatty acids, inorganic phosphate, and serum amino acids (ion exchange chromatography). During fructose infusion, the following metabolic changes were detected: hypoglycemia (20 to 60 mg/dl), increase in blood fructose levels (up to 350 mg/dl), hypophosphatemia (2 to 3 mg/dl), hyperlacticacidemia (up to 60 mg/dl), elevation of plasma ammonia levels (up to 120 mg/dl), increased serum glutamate, and a decrease in serum glutamine, as also hyperuricemia (up to 10 mg/dl). On termination of the fructose infusion, these changes were completely reversible. Analysis of the deaths reported in the literature revealed a known intolerance to fruit or sweets, and that no regular metabolic studies were apparently performed. Although HFI is rare, use should be made of the known advantages of sugar substitutes in post-aggression metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Patients with hereditary fructose intolerance have normal erythrocyte aldolase activity

Erythrocyte fructose 1,6-bisphosphate aldolase (EC 4.1.2.13) activity was measured in eight children and adults with hereditary fructose intolerance and found to be normal when compared with eleven healthy controls. Therefore, hereditary fructose intolerance cannot be diagnosed by assaying red blood cell aldolase.

Fructose-induced hyperlactemia in hyperosmolar syndromes

Severe hyperlactemia of 8.7, 8.6 and 7.9 mmol/l, respectively, developed in three patients with hyperosmolar syndromes (two hypernatremic, 417 and 415 mosmol/kg H2O; one hyperglycemic 437 mosmol/kg H2O) during rehydration treatment with 5% fructose in water (fructose dosage 0.5 g/kg body wt. per hour). After resolution of the electrolyte disturbances, the infusion of fructose at the same dosage increased the plasma lactate concentration in two of the patients to 4.9 and 4.0 mmol/l, indicating near normalization of hepatic lactate utilization. Thus, in addition to peripheral insulin resistance and decreased muscular glucose utilization, the hyperosmolar state is associated with a reduced tolerance to fructose. This is most likely due to an osmolality-dependent impairment of hepatic gluconeogenesis. In rehydration therapy for hyperosmolar syndromes, fructose-containing infusion solutions should no longer be used.

Chronic fructose intoxication after infancy in children with hereditary fructose intolerance. A cause of growth retardation

In two unrelated boys, 5.3 and 3.8 years of age with hereditary fructose intolerance, apparently isolated growth retardation (-2.71 S.D. and -2.40 S.D.) occurred after infancy, even though acute symptomatic fructose intoxication was prevented by restriction of dietary fructose. When more stringent restriction of dietary fructose was instituted (approximately 40 mg per kilogram of body weight per day), growth velocity increased from the 25th to the 97th percentile in one child and from well below the 3d to above the 75th percentile in the other. When restriction of dietary fructose was experimentally relaxed (from 10 to 250 mg per kilogram per day), neither boy had symptoms, hypoglycemia, or evidence of hepatic or renal dysfunction, but both had sustained hyperuricemia and hyperuricosuria and increases in the plasma concentration and urinary excretion of magnesium. We conclude that in patients with hereditary fructose intolerance, clinically important chronic fructose intoxication can occur after infancy without causing symptoms of acute fructose intoxication and can be expressed as an apparently isolated, reversible retardation of somatic growth with a continuing disorder of adenine nucleotide metabolism, characterized in part by recurrently increased rates of degradation of adenine nucleotides.

[Hereditary fructose intolerance (author's transl)]

Hereditary fructose intolerance (HFI) is the most important disturbance in human fructose metabolism. This paper deals with the present knowledge of biochemistry and pathophysiology of this inborn error of metabolism, which is often wrongly diagnosed and gives a detailed description of diagnostic and therapeutic procedures.

Fructose-induced hyperuricemia: observations in normal children and in patients with hereditary fructose intolerance and galactosemia

After the infusion of fructose, 0.25 g/kg body wt, the mean peak plasma uric acid level was 5.4 +/- 0.7 (SEM) mg/100 ml in six normal children and was not significantly increased compared with that of the mean basal value of 4.1 +/- 0.5 mg/100 ml. The mean blood inorganic phosphate (Pi) levels were significantly less than the mean fasting value after fructose. Blood glucose, lactic acid, and fructose levels were significantly increased after fructose, but serum magnesium levels did not change. In two patients with hereditary fructose intolerance (HFI) the peak blood uric acid levels were 12.1 and 7.6 mg/100 ml, respectively, after fructose. In both patients the blood glucose concentrations decreased 69 and 26 mg/100 ml below the fasting levels after fructose. The serum Pi level decreased 2.3 and 1.2 mg/100 ml below fasting values, decrements greater than the mean decrement in serum Pi of 0.8 +/- 0.2 mg/100 ml which occurred in six normal children. The mean uric acid excretion, expressed as milligrams per mg urinary creatinine, was 0.6 +/- 0.1 (SEM) before fructose in the normal children and increased significantly to 1.0 +/- mg/mg creatinine after fructose. In two patients with HFI the uric acid excretion increased four- to fivefold after fructose administration; the increased uric acid excretion in HFI exceeded that of normal children. In three patients with galactosemia, increases in blood uric acid levels after galactose ingestion were similar to those in normal children after fructose, but less than those in patients with HFI after fructose. The serum Pi levels decreased less in galactosemic patients after galactose administration than in patients with HFI after fructose infusion. These studies support the hypothesis that fructose-induced hyperuricemia results from degradation of adenosine monophosphate. This effect appears to be specific for fructose. The lack of hyperruricemia in galactosemia patients after galactose ingestion may be explained by the observation that galactose is phosphorylated more slowly than fructose.