title: Molecular characteristics of patients with glycosaminoglycan storage disorders in Russia.
abstract: BACKGROUND
  The mucopolysaccharidoses (MPSs) are rare genetic disorders caused by mutations in lysosomal enzymes involved in the degradation of glycosaminoglycans (GAGs). In this study, we analyzed a total of 48 patients including MPSI (n=6), MPSII (n=18), MPSIIIA (n=11), MPSIVA (n=3), and MPSVI (n=10).
  
  
  METHODS
  In MPS patients, urinary GAGs were colorimetrically assayed. Enzyme activity was quantified by colorimetric and fluorimetric assays. To find mutations, all IDUA, IDS, SGSH, GALNS, and ARSB exons and intronic flanks were sequenced. New mutations were functionally assessed by reconstructing mutant alleles with site-directed mutagenesis followed with expression of wild-type and mutant genetic variants in CHO cells, measuring enzymatic activity, and Western blot analysis of protein expression of normal and mutated enzymes in cell lysates.
  
  
  RESULTS
  A total of five novel mutations were found including p.Asn348Lys (IDUA) in MPSI, p.Tyr240Cys (GALNS) in MPSIVA, and three ARSB mutations (p.Gln110*, p.Asn262Lysfs*14, and pArg315*) in MPSVI patients. In case of mutations p.Asn348Lys, p.Asn262Lysfs*14, and p.Gln110*, no mutant protein was detected while activity of the mutant protein was <1% of that of the normal enzyme. For p.Tyr240Cys, a trace of mutant protein was observed with a remnant activity of 3.6% of the wild-type GALNS activity. For pArg315*, a truncated 30-kDa protein that had 7.9% of activity of the normal ARSB was detected.
  
  
  CONCLUSIONS
  These data further enrich our knowledge of the genetic background of MPSs.
authors.affiliation: Department of Medical Nanobiotechnology, Pirogov Russian State Medical University, 117997 Moscow, Russia; Department of Molecular Genetic Diagnostics, Division of Laboratory Medicine, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia. Electronic address: dimitry.chistiakov@gmail.com.
authors.forename: Dimitry A
authors.initials: DA
authors.lastname: Chistiakov
authors.affiliation: Department of Molecular Genetic Diagnostics, Division of Laboratory Medicine, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Kirill V
authors.initials: KV
authors.lastname: Savost'anov
authors.affiliation: Department of Psychoneurology and Psychosomatic Pathology, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Lyudmila M
authors.initials: LM
authors.lastname: Kuzenkova
authors.affiliation: Institute of Preventive Pediatrics and Rehabilitation, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Anait K
authors.initials: AK
authors.lastname: Gevorkyan
authors.affiliation: Department of Molecular Genetic Diagnostics, Division of Laboratory Medicine, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Pushkov
authors.affiliation: Department of Molecular Genetic Diagnostics, Division of Laboratory Medicine, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Alexey G
authors.initials: AG
authors.lastname: Nikitin
authors.affiliation: Department of Molecular Genetic Diagnostics, Division of Laboratory Medicine, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Pakhomov
authors.affiliation: Department of Psychoneurology and Psychosomatic Pathology, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Nato D
authors.initials: ND
authors.lastname: Vashakmadze
authors.affiliation: Department of Molecular Genetic Diagnostics, Division of Laboratory Medicine, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Zhurkova
authors.affiliation: Department of Psychoneurology and Psychosomatic Pathology, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Podkletnova
authors.affiliation: Department of Experimental Immunology and Virology, Division of Laboratory Medicine, Institute of Pediatrics, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Nikolai A
authors.initials: NA
authors.lastname: Mayansky
authors.affiliation: Institute of Preventive Pediatrics and Rehabilitation, Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Leila S
authors.initials: LS
authors.lastname: Namazova-Baranova
authors.affiliation: Research Center for Children's Health, 119991 Moscow, Russia.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Baranov
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002648:Child; D006224:Cricetinae; D003412:Cricetulus; D004252:DNA Mutational Analysis; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006025:Glycosaminoglycans / Q000378:metabolism* / Q000652:urine; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009083:Mucopolysaccharidoses / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism / Q000652:urine; D012426:Russia
chemical_list: D006025:Glycosaminoglycans
keywords: Enzyme activity; Glycosaminoglycans; Mucopolysaccharidoses; Mutation