title: [GLB1 gene mutation and clinical characteristics of a patient with mucopolysaccharidosis type IVB].
abstract: OBJECTIVE
  To report the results of clinical characteristics, enzyme activity determination and mutation analysis of GLB1 gene in a Chinese patient with mucopolysaccharidosis (MPS) type IVB (Morquio B disease).
  
  
  METHODS
  A 14-year-old Chinese boy with MPS type IVB was firstly diagnosed by blood leucocytes galactosamine-6-sulfate sulfatase (GALNS) and β-galactosidase (GLB1) determination, who was characterized by short stature, multiplex skeletal abnormalities, difficulty in walking. PCR-sequencing analysis was applied to detect the mutations in GLB1 of the patient.
  
  
  RESULTS
  The patient was characterized by dwarfism, pectus carinatum, kyphosis, normal intelligence, and no neurologic damage of spasms, linguistic capacity and so on. The patient had normal GALNS enzyme activity and very low GLB1 enzyme activity [5.03 nmol/(h·mg) vs. normal value 118 - 413 nmol/(h·mg) ] in leukocytes. A compound heterozygous missense mutations c.442C > T(p.R148C)/c.1454A > G(p.Y485C) in GLB1 gene were detected in this patient. The mutation p.Y485C is a novel variant. With the method of gene analysis of new variant, the mutation p.Y485C was considered to be a pathogenic mutation.
  
  
  CONCLUSIONS
  The MPS IVB patient showed severe multiple skeletal deformities, normal intelligence, no neurologic damage and very low GLB1 enzyme activity, who carries compound heterozygous mutations p.R148C/p.Y485C. The mutation p.Y485C in GLB1 gene may be a novel pathologic mutation of MPS type IVB.
authors.affiliation: Department of Paediatric Endocrinologic, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Hong-lin
authors.initials: HL
authors.lastname: Lei
authors.forename: Jun
authors.initials: J
authors.lastname: Ye
authors.forename: Wen-juan
authors.initials: WJ
authors.lastname: Qiu
authors.forename: Hui-wen
authors.initials: HW
authors.lastname: Zhang
authors.forename: Lian-shu
authors.initials: LS
authors.lastname: Han
authors.forename: Xue-fan
authors.initials: XF
authors.lastname: Gu
mesh_terms: D000293:Adolescent; D000595:Amino Acid Sequence; D044466:Asian People / Q000235:genetics; D002811:Chondroitinsulfatases / Q000235:genetics / Q000378:metabolism; D004252:DNA Mutational Analysis; D006801:Humans; D007596:Joints / Q000473:pathology; D008297:Male; D008969:Molecular Sequence Data; D009085:Mucopolysaccharidosis IV / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D020125:Mutation, Missense; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011859:Radiography; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology; D001616:beta-Galactosidase / Q000235:genetics* / Q000378:metabolism
chemical_list: D002811:Chondroitinsulfatases; C061901:GLB1 protein, human; D001616:beta-Galactosidase