Goat genetics

Scrapie is a fatal conditionally infectious neurodegenerative disease that affects sheep and goats. Disease occurs as a result of attack by pathogenic proteins known as "prions", which alter the normal prion protein (PrPC) into a misfolded, disease-associated form (PrPSc). Abnormal PrPSc is resistant to proteolysis and forms protein strands in the central nervous system and some peripheral tissues that lead to progressive neurodegeneration. Goat scrapie is similar to prion diseases such as Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy (BSE), and sheep scrapie. Animals with this disease are not allowed to be sold or used for food, and it is not recommended to use their milk. Mutations have been identified in the prion protein (PRNP) gene of sheep and goats that can create susceptible or resistant forms of the PrP protein to scrapie. In goats, these mutations include S146 and K222, which confer genetic resistance against classic scrapie. It has been shown that the presence of even one copy of the protective allele prevents goats from getting sick with scrapie.