Mutations in the TARDBP gene,which encodes the Tar DNA binding protein,have been shown to causes of both familial amyotrophic lateral sclerosis (FALS) and sporadic ALS (SALS).Recently,several novel TARDBP exon 6 mutants have been reported in patients with ALS in Europe and America but not in Asia.To further examine the spectrum and frequency of TARDBP exon 6 mutations,we investigated their frequency in ethnic Chinese patients with sporadic ALS.TARDBP exon 6 was screened by direct sequencing in 207 non-SOD1 SALS patients and 230 unrelated healthy controls but no mutations were identified.Our data indicate that exon 6 mutations in TARDBP are not a common cause of SALS in Han Chinese population from Southern Mainland China.