title: Urine analysis of glucose tetrasaccharide by HPLC; a useful marker for the investigation of patients with Pompe and other glycogen storage diseases.
abstract: A high performance liquid chromatography method, adapted from an established urinary sugars method, has been developed for the analysis of a tetraglucose oligomer (Glc(4)) in urine. Pompe disease results from defects in the activity of lysosomal acid α-glucosidase (GAA) with patients typically excreting increased amounts of Glc(4). Rapid determination of GAA in dried blood spots is now possible. However, enzymatic analysis is unable to discriminate between patients with Pompe disease and those individuals harbouring pseudo deficiency mutations. This method was able to quantify Glc(4) levels in all patients analysed with an established diagnosis of Pompe disease, and all controls analysed had Glc(4) levels below the limit of detection for this method. Importantly the method was able to discriminate between an individual known to harbour a pseudo Pompe mutation and patients with Pompe disease, providing a useful supporting test to enzymatic analysis. Sequential measurement of urinary Glc(4) has been proposed to monitor the effects of enzyme replacement therapy (ERT). We observed a clear decrease in Glc(4) levels following commencement of treatment in three patients studied. Additionally, raised levels of Glc(4) were observed in patients with glycogen storage disease (GSD) type Ia and type III suggesting that this method may have applications in other GSDs.
authors.affiliation: Enzyme and Metabolic Unit, Chemical Pathology, Great Ormond Street Hospital for Children, Great Ormond Street, London, WC1N 3JH, UK.
authors.forename: Victoria
authors.initials: V
authors.lastname: Manwaring
authors.forename: Helen
authors.initials: H
authors.lastname: Prunty
authors.forename: Katie
authors.initials: K
authors.lastname: Bainbridge
authors.forename: Derek
authors.initials: D
authors.lastname: Burke
authors.forename: Niamh
authors.initials: N
authors.lastname: Finnegan
authors.forename: Rebecca
authors.initials: R
authors.lastname: Franses
authors.forename: Amanda
authors.initials: A
authors.lastname: Lam
authors.forename: Ashok
authors.initials: A
authors.lastname: Vellodi
authors.forename: Simon
authors.initials: S
authors.lastname: Heales
mesh_terms: D015415:Biomarkers / Q000097:blood / Q000652:urine; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D056947:Enzyme Replacement Therapy / Q000379:methods; D005260:Female; D006008:Glycogen Storage Disease / Q000097:blood / Q000175:diagnosis / Q000201:enzymology / Q000652:urine*; D006009:Glycogen Storage Disease Type II / Q000097:blood / Q000175:diagnosis / Q000201:enzymology / Q000652:urine*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009844:Oligosaccharides / Q000097:blood / Q000235:genetics / Q000652:urine*
chemical_list: D015415:Biomarkers; D009844:Oligosaccharides; C033620:glucose tetrasaccharide