Novel techniques and newer markers for the evaluation of "proximal tubular dysfunction".

Renal Fanconi syndromes are both clinically challenging and physiologically fascinating. The diagnosis requires a certain index of suspicion to correctly identify the clinical symptomatology and pursue the appropriate laboratory evaluations. The renal Fanconi syndrome (FS) is a defect of proximal tubular function attributable to different rare inherited diseases or acquired disorders caused by a multitude of exogenous agents. It can manifest as complete or incomplete FS, characterized by low molecular weight proteinuria, glucosuria, aminoaciduria, and loss of electrolytes, bicarbonate and lactate. Implementation of new methods and recent findings from urinary proteome pattern in patients with renal FS has led to the identification of new markers for proximal tubular dysfunction. Future combined proteomic and metabonomic studies will provide additional potential biomarkers and may help to gain novel insights in the diagnosis and differentiation of the various forms of FS. Moreover, the observation of poor renal uptake of 99 mTc-DMSA in patients with tubular proteinuria, which is not fully understood yet, may also help to elucidate the individual basis of FS in early stages. This review focuses on the new advances in the evaluation of proximal tubular dysfunction in various forms of Fanconi syndrome.

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.

Determinación de substancias reductoras en la orina como método inicial para el diagnóstico temprano de galactosemia e intolerancia hereditaria a la fructuosa en niños con hepatitis / Determination of the reducing substances in the urine as a diagnostic method for galactosemia and fructose intolerance in children with neonatal hepatitis

La determinación de substancias reductoras en orina, se realizó en 40 niños con hepatitis neonatal utilizando, para ello, la prueba de Clinitest y Benedict. Sólo en dos niños se obtuvo como resultado una reacción falsa positiva. Se concluye que el clinitest es un método sencillo, práctico, económico y de gran utilidad para la detección temprana e inicial de galactosemia e intolerancia a la fructuosa. Las que deberán corroborarse en caso necesario posteriormente con un estudio metabólico completo

[Hypercalciuria and hereditary fructose intolerance (author's transl)]. / Hypercalciurie et intolérance héréditaire au fructose.

Hereditary fructose intolerance includes a dysfunction of the proximal renal tubule, which disappears when fructose is excluded from the diet. A 46 month-old girl, fed with such a fructose-free diet since the age of 4 months, presented with a renal hypercalciuria. The significance of this disorder is discussed.