SOD1 and amyotrophic lateral sclerosis: For instance, the D90A mutation in the SOD1 gene was detected in 3 of 28 German families [15]; mutations in the ALS2 gene are linked to a locus on chromosome 2q33, which has been described as a rare juvenile form of ALS, and mutations in the ALS5 gene, linked to chromosome 15q15.1-q21.1, are the most prevalent form of autosomal recessive ALS, especially in families from Asia, North Africa, and Germany [16].