Some experimental data suggest a possible role of tau protein in the pathogenesis of multiple sclerosis (MS) and in experimental autoimmune encephalomyelitis. The aim of this study was to investigate a possible influence of the SNP rs1052553 in the MAPT gene in the risk for relapsing bout onset (relapsing-remitting and secondary progressive) MS.We analyzed the allelic and genotype frequency of MAPT rs1052553, which has been associated with some neurodegenerative diseases, in 259 patients with relapsing bout onset MS and 291 healthy controls, using TaqMan Assays.MAPT rs1052553 allelic and genotype frequencies did not differ significantly between relapsing bout onset MS patients and controls, and were unrelated with the age of onset of MS or gender.These results suggest that MAPT rs1052553 polymorphism is not related with the risk for relapsing bout onset MS.