Polymorphisms in cervid Prnp have been identified at codon 132 of the elk Prnp gene, encoding either methionine (M) or leucine (L) [49], equivalent to that of position 129 (M/Valine) in the human PRNP gene [50], which has significant effects on human prion disease presentation and susceptibility [51,52]. The gene discussed is PRNP; the disease is prion disease.