Transferrin Isoforms, Old but New Biomarkers in Hereditary Fructose Intolerance

Hereditary Fructose Intolerance (HFI) is an autosomal recessive inborn error of metabolism characterised by the deficiency of the hepatic enzyme aldolase B. Its treatment consists in adopting a fructose-, sucrose-, and sorbitol (FSS)-restrictive diet for life. Untreated HFI patients present an abnormal transferrin (Tf) glycosylation pattern due to the inhibition of mannose-6-phosphate isomerase by fructose-1-phosphate. Hence, elevated serum carbohydrate-deficient Tf (CDT) may allow the prompt detection of HFI. The CDT values improve when an FSS-restrictive diet is followed; however, previous data on CDT and fructose intake correlation are inconsistent. Therefore, we examined the complete serum sialoTf profile and correlated it with FSS dietary intake and with hepatic parameters in a cohort of paediatric and adult fructosemic patients. To do so, the profiles of serum sialoTf from genetically diagnosed HFI patients on an FSS-restricted diet (n = 37) and their age-, sex- and body mass index-paired controls (n = 32) were analysed by capillary zone electrophoresis. We found that in HFI patients, asialoTf correlated with dietary intake of sucrose (R = 0.575, p < 0.001) and FSS (R = 0.475, p = 0.008), and that pentasialoTf+hexasialoTf negatively correlated with dietary intake of fructose (R = −0.386, p = 0.024) and FSS (R = −0.400, p = 0.019). In addition, the tetrasialoTf/disialoTf ratio truthfully differentiated treated HFI patients from healthy controls, with an area under the ROC curve (AUROC) of 0.97, 92% sensitivity, 94% specificity and 93% accuracy.

Molecular and clinical findings of Turkish patients with hereditary fructose intolerance

Objectives Hereditary fructose intolerance (HFI) is an autosomal recessive disorder caused by a deficiency in aldolase B that can result in hypoglycemia, nausea, vomiting, abdominal pain, liver and kidney dysfunction, coma, and even death. This study aims to represent the clinical features and molecular genetic analysis data of the patients diagnosed with HFI in our study population. Methods The medical records of the 26 patients with HFI were evaluated retrospectively. Age, gender, clinical findings, metabolic crises, and the results of molecular analyses were recorded. Results The patients with HFI had a good prognosis and the aversion to sugar-containing foods was the main complaint. Seven different variants were identified in the Aldolase B (ALDOB) gene in HFI patients. The most frequent mutations were p.Ala150Pro, p.Ala175Asp had a prevalence of 61 and 30%, respectively, in agreement with the literature and other known variants were found with minor frequencies c.360-363del4(3.8%), p.Asn335Lys(3.8%), and three novel mutations c.113-1_15del4 (3.8%), p.Ala338Val(7.6%), and p.Asp156His(3.8%) were identified at a heterozygous, homozygous, or compound heterozygous level. Conclusions This study results revealed three novel mutations in patients with HFI. On the basis of age of presentation, clinical symptoms, and metabolic crisis, there was no clear-cut genotype-phenotype correlation. This article also demonstrates the importance of screening suspected infants in cases of acute liver failure for prompt diagnosis and treatment of HFI.

Acquired Fanconi Syndrome from Ifosfamide

Fanconi syndrome is a renal proximal tubule defect that causes reabsorption defects of electrolytes. The clinical features of Fanconi syndrome are amino aciduria, proteinuria, hypophosphatemia, metabolic acidosis, and glycosuria. In children, it is usually resulting from a genetic defect, such as cystinosis, galactosemia, tyrosinemia, hereditary fructose intolerance, and Wilson disease [1]. However, in adults, it is usually resulting from medications, toxins, and kidney diseases such as light chain proximal tubulopathy and primary amyloidosis [1]. Ifosfamide is a chemotherapy agent that is well known in the literature to cause Fanconi syndrome. Herein, we present a case of a woman with cervical cancer who developed ifosfamide-induced Fanconi syndrome after her fifth cycle of chemotherapy.

Unarousable child with a short bowel

Unarousable child with short bowelA 4-year-old boy was admitted with progressive lethargy of a few hours’ duration and no other symptoms. His medical history was relevant for short bowel syndrome (SBS), following neonatal volvulus, with residual bowel length of 23 cm and intact ileocecal valve. He had similar self-limiting episodes in the past, after weaning parenteral nutrition, especially after eating large meals. The day before, he had consumed a large amount of apples.Arterial blood gas (ABG) analysis showed metabolic acidosis with normal lactacidaemia (pH 7.09, pCO2 19 mm Hg, pO2 101 mm Hg, HCO3 5.8 mmol/L, BE −24, anion gap 29.4, chloride 116 mmol/L, L-lactate level 4 mmol/L).On admission, the child could be awakened, but he was confused with slurred speech (Glasgow Coma Scale 14), with a body temperature of 37 C°, a heart rate of 125 beats/min and a respiratory rate of 38 breaths/min. The abdomen was distended, without guarding and with normal bowel sounds. Blood glucose levels were normal, as well as white blood cell count, liver and kidney function test and C reactive protein. An abdominal ultrasound ruled out an intussusception. An abdominal X-ray was performed too (see figure 1).Figure 1Abdominal distension with gas and bloating.QuestionsWhich is the most likely diagnosis?EncephalitisD-lactic acidosisDehydration with third space fluid collection and acidosisHereditary fructose intolerance.How is this diagnosis confirmed?D lactic dosageBreath test for bacterial overgrowthUrine organic acid dosageSearch for reductive substances in the stools.How should this patient be managed?Intravenous fluids to facilitate D-lactic excretionRestrict carbohydrates in the dietIntravenous bicarbonatesAntibiotic treatment to reduce bowel bacterial overgrowth.Answers can be found on page 2.