Multiple system involvement in a Japanese patient with a V31A mutation in the SOD1 gene

The superoxide dismutase-1 (SOD1) gene is the first gene for familial amyotrophic lateral sclerosis (ALS) with autosomal dominant inheritance. We describe a Japanese patient who had slowly progressive motor neuron disease with autonomic and sensory disturbances, urine incontinence and sensory neuropathy. This patient was found to have V31A mutation in the SOD1 gene. Although slow progression has been previously observed in patients with ALS caused by several mutations in the SOD1 gene, symptoms unrelated with motor systems are very rare. In addition, MRI showed cerebellar and brainstem atrophy, a finding previously unreported in SOD1-related ALS. The COQ2 gene, a gene very recently reported to be associated with multiple system atrophy, as well as genes for spinocerebellar ataxias was analyzed, the result of which showed no mutation in this patient. The V31A mutation is thus likely to be associated with atypical ALS affecting multiple systems.