Recessively inherited amyotrophic lateral sclerosis: a German family with the D90ACuZn-SOD mutation

Mutations of the SOD1 gene encoding the free radical scavenging enzyme copp er-zinc superoxide dismutase (CuZn-SOD) occur in patients with familial amy otrophic lateral sclerosis (ALS). Recent reports have shown homozygosity fo r a CuZn-SOD mutation in exon 4, the D90A (Asp90Ala) mutation. Other mutati ons described to date show an autosomal dominant pattern of inheritance. Th is is the first description of autosomal recessively inherited ALS in an ou t-bred population in central Europe. This study confirms the earlier descri bed characteristic phenotype reported in D90A homozygous ALS patients in Sc andinavia and supports the theory of the existence of a strong modifying fa ctor in some cases of ALS associated with mutations in the CuZn-SOD gene.