title: Glycosaminoglycan levels in dried blood spots of patients with mucopolysaccharidoses and mucolipidoses.
abstract: Mucopolysaccharidoses (MPSs) and mucolipidoses (ML) are groups of lysosomal storage disorders in which lysosomal hydrolases are deficient leading to accumulation of undegraded glycosaminoglycans (GAGs), throughout the body, subsequently resulting in progressive damage to multiple tissues and organs. Assays using tandem mass spectrometry (MS/MS) have been established to measure GAGs in serum or plasma from MPS and ML patients, but few studies were performed to determine whether these assays are sufficiently robust to measure GAG levels in dried blood spots (DBS) of patients with MPS and ML.
  
  
  
  In this study, we evaluated GAG levels in DBS samples from 124 MPS and ML patients (MPS I=16; MPS II=21; MPS III=40; MPS IV=32; MPS VI=10; MPS VII=1; ML=4), and compared them with 115 age-matched controls. Disaccharides were produced from polymer GAGs by digestion with chondroitinase B, heparitinase, and keratanase II. Subsequently, dermatan sulfate (DS), heparan sulfate (HS-0S, HS-NS), and keratan sulfate (mono-sulfated KS, di-sulfated KS, and ratio of di-sulfated KS in total KS) were measured by MS/MS.
  
  
  
  Untreated patients with MPS I, II, VI, and ML had higher levels of DS compared to control samples. Untreated patients with MPS I, II, III, VI, and ML had higher levels of HS-0S; and untreated patients with MPS II, III and VI and ML had higher levels of HS-NS. Levels of KS were age dependent, so although levels of both mono-sulfated KS and di-sulfated KS were generally higher in patients, particularly for MPS II and MPS IV, age group numbers were not sufficient to determine significance of such changes. However, the ratio of di-sulfated KS in total KS was significantly higher in all MPS patients younger than 5years old, compared to age-matched controls. MPS I and VI patients treated with HSCT had normal levels of DS, and MPS I, VI, and VII treated with ERT or HSCT had normal levels of HS-0S and HS-NS, indicating that both treatments are effective in decreasing blood GAG levels.
  
  
  
  Measurement of GAG levels in DBS is useful for diagnosis and potentially for monitoring the therapeutic efficacy in MPS.
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States; Department of Biological Sciences, University of Delaware, Newark, DE, United States; INAGEMP, Porto Alegre, Brazil.
authors.forename: Francyne
authors.initials: F
authors.lastname: Kubaski
authors.affiliation: Medical Education Development Center, Gifu University, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Orii
authors.affiliation: INAGEMP, Porto Alegre, Brazil; Medical Genetics Service, HCPA, Porto Alegre, Brazil; Department of Genetics, UFRGS, Porto Alegre, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Giugliani
authors.affiliation: Willink Biochemical Genetics Unit, Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust St Mary's Hospital, Manchester, UK.
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Church
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States; Department of Biological Sciences, University of Delaware, Newark, DE, United States.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Mason
authors.affiliation: Vietnam National Children's Hospital, Department of Medical Genetics, Metabolism & Endocrinology, Hanoi, Vietnam.
authors.forename: Vũ Chí
authors.initials: VC
authors.lastname: Dũng
authors.affiliation: Vietnam National Children's Hospital, Department of Medical Genetics, Metabolism & Endocrinology, Hanoi, Vietnam.
authors.forename: Can Thi Bich
authors.initials: CT
authors.lastname: Ngoc
authors.affiliation: Department of Pediatrics, Shimane University, Shimane, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Department of Pediatrics, Shimane University, Shimane, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Kobayashi
authors.affiliation: Department of Medical Genetics, Kasturba Medical College Manipal, Manipal University, India.
authors.forename: Katta M
authors.initials: KM
authors.lastname: Girisha
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fukao
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Orii
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States; Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan. Electronic address: stomatsu@nemours.org.
authors.forename: Shunji
authors.initials: S
authors.lastname: Tomatsu
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002853:Chromatography, Liquid; D003871:Dermatan Sulfate / Q000097:blood; D059788:Dried Blood Spot Testing / Q000379:methods*; D005260:Female; D006025:Glycosaminoglycans / Q000097:blood*; D006497:Heparan Sulfate / Q000097:blood; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007632:Keratan Sulfate / Q000097:blood; D008297:Male; D009081:Mucolipidoses / Q000175:diagnosis* / Q000378:metabolism; D009083:Mucopolysaccharidoses / Q000175:diagnosis* / Q000378:metabolism; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry; D055815:Young Adult
chemical_list: D003871:Dermatan Sulfate; D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D007632:Keratan Sulfate
keywords: Glycosaminoglycans; Hematopoietic stem cell transplantation; Mucolipidoses; Mucopolysaccharidoses; Tandem mass spectrometry