title: A novel mutation (c.200T>C) in the NAGLU gene of a Korean patient with mucopolysaccharidosis IIIB.
abstract: Mucopolysaccharidosis (MPS) IIIB is a lysosomal storage disorder (LSD) caused by abnormalities of the enzyme α-N-acetylglucosaminidase (NAGLU) that is required for degradation of heparan sulfate. The patient in this study was a 4-yr-old boy. He presented with normal height and weight, pectus carinatum, and multiple persistent Mongolian spots on his back. He had mild dysmorphic features with prominent speech developmental delays and, to a lesser extent, motor developmental delays. The cetylpyridinium chloride precipitation test revealed excessive mucopolysacchariduria (657.2 mg glycosaminoglycan/g creatinine; reference range, <175 mg glycosaminoglycan/g creatinine). Thin layer chromatography showed urinary heparan sulfate excretion. NAGLU enzyme activity was significantly decreased in leukocytes (not detected; reference range, 0.9-1.51 nmol/hr/mg protein) as well as in plasma (0.14 nmol/hr/mg protein; reference range, 22.3-60.9 nmol/hr/mg protein). PCR and direct sequencing analysis of the NAGLU gene showed that the patient was a compound heterozygote for 2 mutations: c.200T>C (p.L67P) and c.1444C>T (p.R482W). The c.200T>C mutation was a novel finding. This is the first report of a Korean patient with MPS IIIB who was confirmed by molecular genetic analyses and biochemical investigation.
authors.affiliation: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Kim
authors.forename: Hyung-Doo
authors.initials: HD
authors.lastname: Park
authors.forename: Mi-Ae
authors.initials: MA
authors.lastname: Jang
authors.forename: Chang-Seok
authors.initials: CS
authors.lastname: Ki
authors.forename: Soo-Youn
authors.initials: SY
authors.lastname: Lee
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Sung Yoon
authors.initials: SY
authors.lastname: Cho
authors.forename: Dong-Kyu
authors.initials: DK
authors.lastname: Jin
mesh_terms: D000118:Acetylglucosaminidase / Q000097:blood / Q000235:genetics*; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D002675:Child, Preschool; D002855:Chromatography, Thin Layer; D006579:Heterozygote; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D009084:Mucopolysaccharidosis III / Q000175:diagnosis / Q000235:genetics*; D009154:Mutation; D016133:Polymerase Chain Reaction; D056910:Republic of Korea; D017422:Sequence Analysis, DNA
chemical_list: C033079:alpha-N-acetyl-D-glucosaminidase; D000118:Acetylglucosaminidase
keywords: Korean; Mucopolysaccharidosis IIIB; NAGLU; Novel mutation