Sporadic amyotrophic lateral sclerosis associated with Asp90Ala CuZn-superoxide dismutase mutations in Russia

16 blood samples from Russian patients (Moscow) with idiopathic motor neuron disease were analysed for mutations in the CuZn-superoxide dismutase gene. Two patients (12,5%) with amyotrophic lateral sclerosis (ALS) were found to have a disease related mutation. One patient appears to have autosomal recessive adult-onset ALS associated with homozygosity for Asp90Ala and presents the characteristic phenotype of very slowly ascending paresis with both lower and upper motor neuron signs. The other patient heterozygous for Asp90Ala presents ALS with lumbar onset and rapid progression. Both of cases are apparently sporadic.