Mutation screening of manganese superoxide dismutase in amyotrophic lateral sclerosis.

Seventy-seven cases of ALS were screened for mutations in the manganese superoxide dismutase gene (SOD2). DNA was extracted from CNS tissue and screened using single stranded conformation polymorphism and heteroduplex analysis. No mutations were identified in the entire coding region of the SOD2 gene. The known polymorphism in the mitochondrial targeting sequence was identified. No association was found between this polymorphism and ALS. A further polymorphism was detected in the intronic sequence upstream of exon 4, though no association with ALS was demonstrated. We therefore conclude that mutations in SOD2 do not appear to cause ALS.