Rapid detection of common mutations in the arylsulfatase A gene

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · American Journal of Human Genetics

OSTI ID:134741

Coulter-Mackie, M B ^[1]

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1. Univ. of Western Ontario (Canada)

Metachromatic leukodystrophy (MLD), an autosomal recessive lysosomal storage disease results from a deficiency of arylsulfatase A activity. This disease is usually fatal within a few years of onset in the pediatric age group. A pseuodeficiency occurs in up to 15% of alleles in the general population which significantly decreases enzyme activity. Although there is no clinical phenotype associated with the pseudodeficiency, the decreased enzyme activity can complicate interpretation of biochemical assay results particularly in the case of potential heterozygous carriers of MLD. Two mutations have been found to be simultaneously associated with the pseudodeficiency: one at a glycosylatin site in exon 6 and one in the polyA addition signal. Another mutation, the `I` allele has been reported in up to 50% of alleles in the severe infantile onset form of MLD. The deleterious mutation in this case is in the +1 position of intron 2. In order to screen for these commonly occurring mutations in the arylsulfatase A gene, a simple combination of PCR amplification from genomic DNA and restriction enzyme digestions was developed for each situation. In the case of the pseuodeficiency mutations, oligonucleotide primers were designed which incorporated a single base mismatch 3 bases upstream from the 3{prime} end of the primer so that the presence of the mutation created new MaeIII restriction site in the case of the glycosylation site or an RsaI site in the case of the polyA site. The `I` allele mutation creates a new MvaI site without the use of mismatches. These tests have successfully detected the mutations in individuals suspected of having the pseudodeficiency on the basis of biochemical assay. The `I` allele was detected in 1 of 16 MLD alleles analyzed.

• OSTI ID: 134741
• Report Number(s): CONF-941009--
• Journal Information: American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
AGE DEPENDENCE
DETECTION
ENZYME ACTIVITY
ENZYMES
EXONS
GENE MUTATIONS
GENES
HEREDITARY DISEASES
INTRONS
LYSOSOMES
METABOLIC DISEASES
MORTALITY
PATIENTS
PHENOTYPE
POLYMERASE CHAIN REACTION
RECESSIVE MUTATIONS
SCREENING
STORAGE