title: Four novel mutations in the β-galactosidase gene identified in infantile type of GM1 gangliosidosis.
abstract: OBJECTIVE
  The aim of this study is to find out mutations of Turkish GM1 gangliosidosis patients and to make genotype-phenotype correlations.
  
  
  METHODS
  β-galactosidase activities were measured by using fluorometric substrate. Mutation screening of 16 exons of β-galactosidase gene and mutation detection were done by PCR-SSCP and DNA sequencing, respectively.
  
  
  RESULTS
  Four new mutations, c.188_189insT in exon 2, c.569_570insA in exon 6, p.K142Q in exon 4, p.G190D in exon 6, and one known mutation p.P549L in exon 15, were identified in the β-galactosidase gene in 5 Turkish patients. Mutations in exons 4 and 6 are in the active site and mutation in exon is in the galactose-binding domain of the β-galactosidase gene.
  
  
  CONCLUSIONS
  This is the first mutational analysis performed in Turkish GM1 gangliosidosis patients and shows the molecular heterogeneity of the disease in Turkish population. All identified mutations result in severe enzyme deficiency and infantile phenotype.
authors.affiliation: Department of Medical Biochemistry, Hacettepe University Faculty of Medicine, Ankara, Turkey.
authors.forename: Başak
authors.initials: B
authors.lastname: Celtikçi
authors.forename: Halil İbrahim
authors.initials: Hİ
authors.lastname: Aydın
authors.forename: Serap
authors.initials: S
authors.lastname: Sivri
authors.forename: Müjgan
authors.initials: M
authors.lastname: Sönmez
authors.forename: Meral
authors.initials: M
authors.lastname: Topçu
authors.forename: Hatice Asuman
authors.initials: HA
authors.lastname: Ozkara
mesh_terms: D020134:Catalytic Domain; D004252:DNA Mutational Analysis; D005091:Exons; D016537:Gangliosidosis, GM1 / Q000453:epidemiology / Q000235:genetics*; D056726:Genetic Association Studies; D015894:Genome, Human; D006801:Humans; D016254:Mutagenesis, Insertional; D020125:Mutation, Missense; D018807:Polymorphism, Single-Stranded Conformational; D014421:Turkey / Q000453:epidemiology; D001616:beta-Galactosidase / Q000235:genetics*
chemical_list: C061901:GLB1 protein, human; D001616:beta-Galactosidase