Three cases of xanthinuria identified by gas chromatography/mass spectrometry-based urine metabolomics.

Introduction: Early diagnosis of patients with urolithiasis or hypouricemia owing to inborn errors of hypoxanthine metabolism is important in preventing renal failure or drug-induced toxicity.

Case Presentation: We identified three patients with xanthinuria using gas chromatography/mass spectrometry-based urine metabolomics: a 72-year-old male with bladder stone, a severe hypouricemic 59-year-old female with type 2 diabetes mellitus, and an 8-year and 9-month-old female who was first discovered to harbor a mutation in the xanthine dehydrogenase gene using whole-exome sequencing, but had a normal molybdenum cofactor sulfurase gene. Hydantoin-5-propionate was detected in the first and third patients but not in the second, suggesting that the first and second patients had type I and II xanthinuria, respectively.

Identification of new biomarkers of pyridoxine-dependent epilepsy by GC/MS-based urine metabolomics.

α-Aminoadipic semialdehyde and its cyclic form (Δ-piperideine-6-carboxylate) accumulate in patients with α-aminoadipic semialdehyde dehydrogenase (AASADH; antiquitin; ALDH7A1) deficiency. Δ-Piperideine-6-carboxylate is known to react with pyridoxal 5'-phosphate (PLP) to form a Knoevenagel condensation product, resulting in pyridoxine-dependent epilepsy. Despite dramatic clinical improvement following pyridoxine supplementation, many patients still suffer some degree of intellectual disability due to delayed diagnosis.

Faecal Micro-RNAs in Inflammatory Bowel Diseases.

Background And Aims: Faecal biomarkers are used as indicators of disease activity in inflammatory bowel diseases [IBD], which include Crohn's disease [CD] and ulcerative colitis [UC]. Micro-RNAs [miRNAs] are small non-coding RNAs detectable in extracellular fluids and can be used as clinical biomarkers. The aim of this study was to determine if faecal miRNA composition is altered in IBD.

A case of dihydropyrimidinase deficiency incidentally detected by urine metabolome analysis.

Dihydropyrimidinase deficiency is a rare autosomal recessive disease affecting the second step of pyrimidine degradation. It is caused by mutations in the DPYS gene. Only approximately 30 cases have been reported to date, with a phenotypical variability ranging from asymptomatic to severe neurological illness.

A Japanese case of β-ureidopropionase deficiency with dysmorphic features.

β-Ureidopropionase deficiency is a rare autosomal recessive disease affecting the last step of pyrimidine degradation, and it is caused by a mutation in the UPB1 gene. Approximately 30 cases have been reported to date, with a phenotypical variability ranging from asymptomatic to severe neurological illness. Non-neurological symptoms have been rarely reported.