[Amyotrophic lateral sclerosis and superoxide dismutase--a review]

The recent observation that mutations in cytosolic CuZn-superoxide dismutase (CuZn-SOD) are associated with amyotrophic lateral sclerosis (ALS) suggests that the disease arises from a perturbation of the homeostasis of free radicals resulting in neuronal degeneration by reactive oxygen species. The stability is altered in these mutant molecules, but without necessarily reducing the specific activity of the CuZn-SOD molecule. Substantial evidence argues that the disease arises not from the loss of CuZn-SOD function, but rather from an adverse or novel property of the mutant enzyme molecule. The mechanism for this acquired adverse function is, as yet, completely unknown. SOD research is an important step for a better understanding of the pathogenesis of ALS.