PRNP and scrapie: Collectively, within the U.S. goat population there are goats with PRNP sequences that are associated with prolonged incubation periods and scrapie resistance, and the resistance associated alleles could be used to support breeding programs for enhanced scrapie resistance in goats reared in the U.S. It is therefore important to further investigate the caprine PRNP genetic variability using more herds naturally exposed to scrapie to clarify the association between PRNP genotypes and scrapie resistance or susceptibility.