Molecular analyses of Cu/Zn superoxide dismutase gene in patients with familial amyotrophic lateral sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a degenerative disorder characterized by selective damage to the neural system that mediates voluntary movement. Death usually occurs within a few years of onset. Although the pathophysiologic process of ALS remains unknown, about 5 to 10% of cases are familial. We recently identified five different mutations in six familial ALS (FALS) families. The mutations identified in our FALS families are H46R, L84V, I104F, S134N, V148I. The enzymatic activities of Cu/Zn SOD of erythrocyte or skin fibroblasts were significantly reduced in the all affected patients. These mutations account for fifty percent of all FALS families screened, although Cu/Zn SOD mutations are responsible for less than twenty percent in Western population. Our results indicate that the progression of the disease with Cu/Zn SOD mutations is usually related to each mutation.