Screening of mutations in superoxide dismutase 1 gene in Chinese with familiar amyotrophic lateral sclerosis / 中华神经科杂志

ABSTRACT

Objective To identify the mutations in Cu/Zn superoxide dismutase ( SOD1 ) gene in three Chinese kindreds with amyotrophic lateral sclerosis ( ALS), compare the genotypes with those found in other ethnic groups and to analyze the clinical characteristics.Methods The diagnosis of ALS met El Escorial ALS diagnostic criteria.Genomic DNA was extracted from peripheral blood in ALS patients using standard procedure.PCR amplifications of five exons of SOD1 were performed using primers as described in the previous publication.The PCR products were directly sequenced.Results A heterozygous mutation H46R was found in four affected members in a family with middle age onset and slowly progressive ALS.A heterozygous mutation of G72C was identified in a 20-year-old male who died of respiratory failure after two years of ALS.His father carried the same mutation without clinical phenotype.In the third family with 20affected members with middle age onset and rapidly progress, a mutation of E13V was identified in 5 affected subjects.Conclusions This study is the first large screening of SOD1 mutation in Chinese familiar ALS patients.H46R has previously been found only in Japanese and Pakistanis; this is the first report in Chinese, suggesting H46R may be specific to Asians.The family with mutation G72C presented decreased penetrance, therefore screening SOD1 mutation in sporadic cases and unaffected family members is necessary.E133V is the first reported mutation and needs more study to investigate its effect on the disease.