Resistance to classical scrapie in experimentally challenged goats carrying mutation K222 of the prion protein gene

Vet Res. 2012 Feb 1;43(1):8. doi: 10.1186/1297-9716-43-8.


Susceptibility of sheep to scrapie, a transmissible spongiform encephalopathy of small ruminants, is strongly influenced by polymorphisms of the prion protein gene (PRNP). Breeding programs have been implemented to increase scrapie resistance in sheep populations; though desirable, a similar approach has not yet been applied in goats. European studies have now suggested that several polymorphisms can modulate scrapie susceptibility in goats: in particular, PRNP variant K222 has been associated with resistance in case-control studies in Italy, France and Greece. In this study we investigated the resistance conferred by this variant using a natural Italian goat scrapie isolate to intracerebrally challenge five goats carrying genotype Q/Q 222 (wild type) and five goats carrying genotype Q/K 222. By the end of the study, all five Q/Q 222 goats had died of scrapie after a mean incubation period of 19 months; one of the five Q/K 222 goats died after 24 months, while the other four were alive and apparently healthy up to the end of the study at 4.5 years post-challenge. All five of these animals were found to be scrapie negative. Statistical analysis showed that the probability of survival of the Q/K 222 goats versus the Q/Q 222 goats was significantly higher (p = 0.002). Our study shows that PRNP gene mutation K222 is strongly associated with resistance to classical scrapie also in experimental conditions, making it a potentially positive target for selection in the frame of breeding programs for resistance to classical scrapie in goats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Electrophoresis, Polyacrylamide Gel / veterinary
  • Female
  • Goat Diseases / etiology
  • Goat Diseases / genetics*
  • Goat Diseases / pathology
  • Goat Diseases / transmission
  • Goats
  • Italy
  • Luminescent Measurements / veterinary
  • Male
  • Mutation
  • Polymerase Chain Reaction / veterinary
  • Polymorphism, Genetic
  • Prions / genetics*
  • Prions / metabolism
  • Scrapie / etiology
  • Scrapie / genetics*
  • Scrapie / pathology
  • Scrapie / transmission


  • Prions