Allelic variants at codon 146 in the PRNP gene show significant differences in the risk for natural scrapie in Cypriot goats

SUMMARY Previous studies have shown the association between the polymorphisms serine (S) or aspartic acid (D) at codon 146 of the PRNP gene and resistance to scrapie. All goats aged >12 months (a total of 1075 animals) from four herds with the highest prevalence of scrapie in the country were culled and tested, of which 234 (21·7%) were positive by either the rapid test or immunohistochemistry (IHC) for any of the tissues tested. The odds of scrapie infection occurring in NN 146 goats was 101 [95% credible interval (CrI) 19–2938] times higher than for non-NN 146 or unknown genotypes. IHC applied to lymphoreticular tissue produced the highest sensitivity (94%, 95% CrI 90–97). The presence of putatively resistant non-NN 146 alleles in the Cypriot goat population, severely affected by scrapie, provides a potential tool to reduce/ eradicate scrapie provided that coordinated nationwide breeding programmes are implemented and maintained over time.