A specific superoxide dismutase mutation is on the same genetic background in sporadic and familial cases of amyotrophic lateral sclerosis
- Univ. of Edinburgh (United Kingdom)
- Dundee Royal Infirmary (United Kingdom); and others
Amyotrophic lateral sclerosis (ALS) is a degenerative disease of motor neurons, causing progressive muscular atrophy, weakness, and death from respiratory failure, often within 2-3 years. Although most cases are sporadic, some 5%-10% are inherited as autosomal dominants with age-dependent penetrance. An ALS locus has been mapped to chromosome 21q, and causative mutations identified in the Cu/Zn superoxide dismutase (SOD1) gene. A majority of SOD1 mutations have been found in cases with a clear family history of ALS. However, we and others have also described SOD1 mutations in patients where the disease appears to be sporadic. This is especially true for the missense mutation in codon 113 of the SOD1 gene, which substitutes threonine for isoleucine (I113T). One explanation for this finding is that this codon is a mutational hot spot with sporadic cases representing new mutations. Another is that the inherited nature of the cases is disguised by the reduced penetrance of this specific mutation. We have now shown that each of six unrelated cases of I113T mutation that we have collected in the Scottish population occurs on the same genetic background. Association analysis of multiple flanking loci on chromosome 21q supports the conclusion of a founder effect, with the original mutational event occurring {ge}10 generations ago. 12 refs., 1 fig., 1 tab.
- OSTI ID:
- 508236
- Journal Information:
- American Journal of Human Genetics, Vol. 59, Issue 5; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
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Identification of new mutations in the Cu/Zn superoxide dismutase gene of patients with familial amyotrophic lateral sclerosis
Identification of new mutations in familial amyotrophic lateral sclerosis