Further evidence that D90A-SOD1 mutation is recessively inherited in ALS patients in Italy.

Mutations in the Cu/Zn superoxide dismutase 1 (SOD1) gene have been reported to cause adult-onset autosomal dominant amyotrophic lateral sclerosis (FALS). In sporadic cases (SALS), de novo mutations in the SOD1 gene have occasionally been observed. All the SOD1 mutations are autosomal dominantly inherited with the exception of D90A. To date, in Italy, only two sporadic ALS cases carrying the D90A mutation have been reported in a homozygous state. We investigated for the presence of this mutation in 169 unrelated ALS patients from southern Italy. The genetic analysis revealed three ALS patients (1.8%) with mild phenotype carrying the homozygous D90A mutation.

Sporadic ALS is not associated with VAPB gene mutations in Southern Italy.

Mutations in the Cu/Zn superoxide dismutase (Sod1) gene have been reported to cause adult-onset autosomal dominant Amyotrophic Lateral Sclerosis (FALS). In sporadic cases (SALS) de novo mutations in the Sod1 gene have occasionally been observed. The recent finding of a mutation in the VAMP/synaptobrevin-associated membrane protein B (VAPB) gene as the cause of amyotrophic lateral sclerosis (ALS8), prompted us to investigate the entire coding region of this gene in SALS patients. One hundred twenty-five unrelated patients with adult-onset ALS and 150 healthy sex-age-matched subjects with the same genetic background were analyzed. Genetic analysis for all exons of the VAPB gene by DHPLC revealed 5 variant profiles in 83 out of 125 SALS patients. Direct sequencing of these PCR products revealed 3 nucleotide substitutions. Two of these were found within intron 3 of the gene, harbouring 4 variant DHPLC profiles. The third nucleotide variation (Asp130Glu) was the only substitution present in the coding region of the VAPB gene, and it occurred within exon 4. It was found in three patients out of 125. The frequency of the detected exon variation in the VAPB gene was not significantly different between patients and controls. In conclusion, our study suggests that VAPB mutations are not a common cause of adult-onset SALS.