We report here a case of Gerstmann-Sträussler-Scheinker (GSS) disease with a new mutation at the codon 232 (Met to Thr) of the PRNP gene. This case was characterized by PrP-immunopositive kuru and multicentric plaques; these plaques were also seen in the cerebral cortex, hippocampus and in the deep subcortical nuclei. Diffuse PrP depositions were also detected. In the temporal cortex, a few plaques were immunopositive for both PrP and Abeta; the latter was expressed at the periphery of the PrP-immunopositive cores. This mutation was absent from 40 healthy Polish controls and from 16 other Polish CJD cases, and we therefore believe that 232Thr is a new pathogenic mutation and not a benign polymorphism.