Bovine spongiform encephalopathy (BSE) belongs to a group of diseases called transmissible spongiform encephalopathies (TSE). With the occurrence of the BSE crisis, several studies have been started to evaluate sequence variabilities in the prion protein gene (PRNP) to assess their possible associations with BSE. In contrast to sheep, goat and humans no polymorphisms in the coding sequence of PRNP leading to a susceptibility/resistance towards TSE have been reported in cattle. However, promising associations between polymorphisms in the regulatory region of PRNP and the disease have been reported. In parallel to these investigations, several genome-wide DNA marker scans have been reported and QTL regions that are significantly associated with BSE susceptibility/resistance (BTA 17 and X/Yps) were detected.