A cross-sectional study of PRNP gene in two native Sicilian goat populations in Italy; a relation between prion gene polymorphysms and scrapie incidence?
Transmissible spongiform encephalopathies (TSEs) are a group of neurodegenerative diseases affecting humans and animals and scrapie in small ruminants is considered the archetype of TSEs. Derivata di Siria is a native dairy goat of Sicily (South-Italy), which is related to Syrian goat breeds. Scrapie is considered endemic in Sicily since 1997 following the administration of an infected vaccine. Derivata di Siria goats were involved in six out of 66 scrapie infected flocks in Sicily. Prion protein gene (PRNP) analysis revealed that none of the scrapie cases carried the p.Gln222Lys variant. Sequencing of PRNP in this goat population showed a high frequency (15%) of the p.Gln222Lys variant confirming its association with scrapie resistance. PRNP polymorphisms were also analysed in the population of Pantelleria, a small Sicilian Island where scrapie has never been reported. The native goat breed “Pantesca” was maintained up to almost 80 years ago and the size of the sheep population on this island has historically been very low. Currently a cross-breed goat population of 253 heads is present on the island. PRNP genotyping of Pantelleria goats showed genetic variation, with low presence of wild type goats and the lack of protective alleles. These data reinforce the association between PRNP polymorphisms in small ruminants and scrapie incidence
