Genetyczne aspekty scrapie u owiec

Scrapie is a fatal, neurodegenerative disease occurring in sheep, goats and mufflons. It is commonly believed that its infectious agent is a protease-resistant form of host-encoded prion protein (PrP). Polymorphism of the coding region of PrP genes has been analyzed in many countries. Polymorphism of codons 136, 154 and 171 has been associated with outbreaks of scrapie. Valine (V) in codon 136, arginine (R) in codon 154, glutamine (Q) and histidine (H) in codon 171 are associated with susceptibility to scrapie while histidine (H) in codon 154 and arginine (R) in codon 171 are associated with resistance to the illness. Alanine (A) in codon 136 is associated with low susceptibility to scrapie.