Isolation and characterization of the normal canine beta-galactosidase gene and its mutation in a dog model of GM1-gangliosidosis

J Inherit Metab Dis. 2000 Sep;23(6):593-606. doi: 10.1023/a:1005630013448.


The acid beta-galactosidase cDNA of Portuguese Water dogs was isolated and sequenced. The entire coding region of the gene consists of 2004 nucleotides encoding a protein of 668 amino acids. Its encoding sequence indicates approximately 86.5% identity at the nucleotide level and about 81% identity at the amino acid level with the encoding region of the human acid beta-galactosidase gene. The deduced amino acid sequence contains a 24-amino-acid putative signal sequence, six possible glycosylation sites, and seven cysteine residues. A homozygous recessive mutation, causing canine GM1-gangliosidosis, was identified at nucleotide G200-->A in exon 2 resulting in an Arg60-->His (mutation R60H) amino acid substitution. The mutation creates a new restriction enzyme site for Pml1. Genotyping 115 dog samples for this acid beta-galactosidase gene alteration readily distinguished affected homozygous recessives (n=5), heterozygous carriers (n=50) and normal homozygotes (n=60). DNA mutation analysis provided a method more specific than enzyme assay of beta-galactosidase for determination of carriers.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cysteine / analysis
  • DNA Mutational Analysis
  • Disease Models, Animal*
  • Dogs
  • Gangliosidosis, GM1 / genetics*
  • Genotype
  • Glycosylation
  • Heterozygote
  • Homozygote
  • Humans
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Mutation*
  • Sequence Homology
  • beta-Galactosidase / chemistry
  • beta-Galactosidase / genetics*


  • beta-Galactosidase
  • Cysteine