Copper/zinc superoxide dismutase 1 and sporadic amyotrophic lateral sclerosis: analysis of 155 cases and identification of a novel insertion mutation

Ann Neurol. 1997 Nov;42(5):803-7. doi: 10.1002/ana.410420518.


Amyotrophic lateral sclerosis (ALS) is a progressive paralytic disorder resulting from the degeneration of motor neurons in the brain and spinal cord and leading to death within 5 years of symptom onset. The great majority of ALS cases are sporadic, with the familial form (FALS) representing fewer than 10% of all cases. Mutations in the copper/zinc superoxide dismutase 1 (SOD-1) gene have previously been identified as the underlying cause of approximately 20% of FALS cases. As the familial and sporadic forms of the disease are clinically similar, we have sought to determine whether such mutations in SOD-1 underlie any sporadic ALS cases. We have screened 155 sporadic cases by single-strand conformation polymorphism and have identified 4 sporadic cases that possess point mutations in exon 4 of the SOD-1 gene. Two of these mutations are identical to those previously reported in FALS cases. One mutation is novel, resulting in a frameshift at Val118 due to the replacement of G (first base in the last codon of exon 4) by AAAAC. This mutation results in a truncated SOD-1 protein due to the introduction of a stop codon three residues into exon 5.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amyotrophic Lateral Sclerosis / enzymology
  • Amyotrophic Lateral Sclerosis / genetics*
  • Cloning, Molecular
  • DNA Mutational Analysis
  • Exons / genetics
  • Humans
  • Introns / genetics
  • Point Mutation*
  • Polymerase Chain Reaction
  • Polymorphism, Single-Stranded Conformational
  • Superoxide Dismutase / genetics*


  • Superoxide Dismutase