title: Metachromatic leucodystrophy in three families from Nova Scotia, Canada: a recurring mutation in the arylsulphatase A gene.
abstract: Metachromatic leucodystrophy (MLD) is a lysosomal storage disease resulting from a deficiency of arylsulphatase A. We have identified a child with infantile onset MLD who is homozygous for an A212V mutation, a mutation previously reported but not further characterised. We have introduced this mutation into an arylsulphatase A expression vector by site directed mutagenesis. Transient expression of this mutant plasmid in COS cells yields very low levels of arylsulphatase A activity consistent with the patient's phenotype. The arylsulphatase A pseudodeficiency also segregates in this family causing difficulty in interpreting enzyme levels in the absence of DNA data. Two other patients from the same province, also carrying the A212V allele, have juvenile and adult onset MLD and are heterozygous for P426L ("A" allele) and I179S alleles respectively, known late onset alleles.
authors.affiliation: Department of Pediatrics, University of British Columbia, Vancouver, Canada.
authors.forename: M B
authors.initials: MB
authors.lastname: Coulter-Mackie
authors.forename: L
authors.initials: L
authors.lastname: Gagnier
authors.forename: M J
authors.initials: MJ
authors.lastname: Beis
authors.forename: D A
authors.initials: DA
authors.lastname: Applegarth
authors.forename: D E
authors.initials: DE
authors.lastname: Cole
authors.forename: K
authors.initials: K
authors.lastname: Gordon
authors.forename: M D
authors.initials: MD
authors.lastname: Ludman
mesh_terms: D000328:Adult; D017668:Age of Onset; D000483:Alleles; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002553:Cerebroside-Sulfatase / Q000172:deficiency / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D017931:DNA Primers / Q000235:genetics; D005260:Female; D006801:Humans; D007966:Leukodystrophy, Metachromatic / Q000201:enzymology* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009674:Nova Scotia; D010375:Pedigree; D010641:Phenotype; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational
chemical_list: D017931:DNA Primers; D002553:Cerebroside-Sulfatase