title: Evaluation of urinary keratan sulfate disaccharides in MPS IVA patients using UPLC-MS/MS.
abstract: BACKGROUND
  Glycosaminoglycan analysis for the diagnosis of Morquio patients has been daunting due to lack of sensitivity/specificity of the dimethylmethylene blue-based spectrophotometry methodology, routinely used by several clinical laboratories. MS methods have been devised for quantification of keratan sulfate for Morquio patients, but some used tributylamine in mobile phases, or did not use isotope-labeled internal standards. Results & methodology: An UPLC-MS/MS methodology aiming to solve these issues was devised, based on the digestion of keratan sulfate to obtain two major disaccharides. Abnormal urinary results were obtained for all Morquio A patients, while the dimethylmethylene blue-based spectrophotometry methodology showed normal results for four out of nine cases.
  
  
  CONCLUSIONS
  The devised method is sensitive, specific and suitable for high-risk screening and longitudinal evaluation of treated patients.
authors.affiliation: Division of Medical Genetics, Department of Pediatrics, Faculty of Medicine & Health Sciences, Centre de recherche - CHUS, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada.
authors.forename: Christiane
authors.initials: C
authors.lastname: Auray-Blais
authors.affiliation: Division of Medical Genetics, Department of Pediatrics, Faculty of Medicine & Health Sciences, Centre de recherche - CHUS, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada.
authors.forename: Pamela
authors.initials: P
authors.lastname: Lavoie
authors.affiliation: Division of Medical Genetics, Department of Pediatrics, Faculty of Medicine & Health Sciences, Centre de recherche - CHUS, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada.
authors.forename: Bruno
authors.initials: B
authors.lastname: Maranda
authors.affiliation: Division of Medical Genetics, Department of Pediatrics, Faculty of Medicine & Health Sciences, Centre de recherche - CHUS, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Boutin
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007632:Keratan Sulfate / Q000652:urine*; D008297:Male; D009085:Mucopolysaccharidosis IV / Q000188:drug therapy / Q000652:urine*; D012016:Reference Values; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards; D016482:Urinalysis / Q000379:methods* / Q000592:standards; D055815:Young Adult
chemical_list: D007632:Keratan Sulfate
keywords: MPS IVA; MS; Morquio A syndrome; UPLC–MS/MS; diagnosis; keratan sulfate; mucopolysaccharidosis