Gerstmann-Sträussler-Scheinker disease (GSS) is a slowly progressive hereditary autosomal dominant disease (OMIM: 137440) and the first human transmissible spongiform encephalopathy (TSE) in which a mutation in a gene encoding for prion protein (PrP) was discovered. Its true prevalence is difficult to estimate but figures within the range of 1-10/100,000,000 are quoted. GSS is defined as a neurodegenerative disease "in family with dominantly inherited progressive ataxia and/or dementia): encephalo(myelo)pathy with multi-centric PrP plaques". In this review, we summarise data on all the families with GSS. The hallmark of the GSS neuropathology is the multi-centric plaque but the pattern varies between families. In the second part of this review the experimental data using experimental models of GSS in transgenic mice are summarised as well as structural biology of mutated PrP in GSS.