Abnormally high levels of SOD1 mRNA in a patient with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) occurs in both sporadic (SALS) and, less commonly, familial (FALS) forms. In familial cases, inheritance is usually autosomal dominant, but recessive transmission of the disease also occurs.6 In a subset (15-20%) of FALS cases the disease is caused by mutations in the gene coding Cu-Zn superoxide dismutase (Cu-Zn SOD1) on chromosome 21.5 In SALS cases, mutations have rarely been found. Variability in disease duration exists within families with the same SOD1 mutation.