title: A Korean patient with Morquio B disease with a novel c.13_14insA mutation in the GLB1 gene.
abstract: Mutations in the GLB1 gene, which encodes acid β-galactosidase, can result in two disease phenotypes: GM1-gangliosidosis (MIM #230500) and Morquio B disease (Mucopolysaccharidosis type IVB, MIM #253010). Morquio B disease occurs much more infrequently than GM1-gangliodosis and is characterized by severe skeletal manifestations (dysostosis multiplex) without central nervous system involvement. Here, we report the first known Korean patient with Morquio B disease. A 7-year-old boy presented with severe progressive skeletal dysplasia including scoliosis, contractures of the elbows, xenu valgum, funnel chest, and trigger thumb requiring surgical intervention. The patient had normal neurological functions and mental status when evaluated by pediatric neurologists. The patient's urinary glycosaminoglycans, measured by the cetylpyridinium chloride (CPC) precipitation test, were 252.8 CPC unit/g creatinine (reference range < 175). Thin layer chromatography of urine showed a keratan sulfate band. Enzyme activity of β-galactosidase in leukocytes was 1.15 nmol/hr/mg protein (reference range 78.1-117.7; 1-1.5% of normal). The patient had compound heterozygous mutations of the GLB1 gene: c.13_14insA (p.L5HfsX29), which was reported in a patient with infantile GM1 gangliosidosis with the near-complete absence of enzyme activity, and c.367G>A (p.G123R), which is a novel frame-shift mutation. In summary, we report the first known Korean patient with Morquio B disease and a novel mutation (c.13_14insA of GLB1).
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-dong, Gangnam-gu, Seoul, South Korea.
authors.forename: Young Bae
authors.initials: YB
authors.lastname: Sohn
authors.forename: Hyung-Doo
authors.initials: HD
authors.lastname: Park
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Park
authors.forename: Se-Hwa
authors.initials: SH
authors.lastname: Kim
authors.forename: Sung-Yoon
authors.initials: SY
authors.lastname: Cho
authors.forename: Ah-Ra
authors.initials: AR
authors.lastname: Ko
authors.forename: Chang-Seok
authors.initials: CS
authors.lastname: Ki
authors.forename: Sunghee
authors.initials: S
authors.lastname: Yeau
authors.forename: Dong-Kyu
authors.initials: DK
authors.lastname: Jin
mesh_terms: D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D002648:Child; D004252:DNA Mutational Analysis; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009085:Mucopolysaccharidosis IV / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011859:Radiography; D056910:Republic of Korea; D001616:beta-Galactosidase / Q000235:genetics*
chemical_list: C061901:GLB1 protein, human; D001616:beta-Galactosidase