A screening for superoxide dismutase-1 D90A mutation in Italian patients with sporadic amyotrophic lateral sclerosis.

The Aspartate-90-Alanine (D90A) mutation on SOD-1 gene, the only known change causing recessive familial amyotrophic lateral sclerosis (FALS), is associated with a uniform phenotype characterized by slowly ascending paresis and long survival. Originally reported in Scandinavian cases, it has also been detected in patients from other countries. A common haplotype, probably of Scandinavian origin, has been demonstrated in D90A recessive pedigrees. In this study we screened the SOD-1 gene for the D90A mutation in 56 Italian patients from north-west Tuscany with sporadic ALS in order to evaluate the occurrence of this mutation and its genotype-phenotype correlation in Italy. We found the homozygous D90A mutation in one patient (1.8%), harboring the classical phenotype related to this mutation. No other mutations were detected in any of the five SOD-1 exons in our group. Our results confirm that recessive D90A mutation is present in Italy and it is associated with the phenotype already described A screening for that mutation, easily made by RFLP, should be made in sporadic ALS patients, especially where clinical investigation indicates its presence.