Submitted to: Journal of General Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/1999
Publication Date: N/A
Interpretive Summary: Chronic wasting disease is a fatal neurologic disease of deer and elk, reported in a small area of the United States and in captive herds. The disease is related to sheep scrapie and bovine spongiform encephalopathy. Susceptibility to sheep scrapie is under control of the PrP gene. Sheep with certain PrP genotypes rarely develop scrapie under experimental or field conditions. Selection of breeding elk with low susceptibility PrP genes would be a useful management tool to reduce the prevalence of the disease in captive herds. In this study, we examined the PrP genotypes of captive and free ranging elk with chronic wasting disease and compared the frequencies of these genotypes with those of unaffected elk in several populations. We determined that elk with the most common genotype were more likely to develop chronic wasting disease than were elk with the two other genotypes. Additional studies of elk with the low incidence genotype will be necessary before we can determine the level of resistance to chronic wasting disease in these animals.
Technical Abstract: The PrP gene encodes the putative causative agent of the transmissible spongiform encephalopathies (TSE), a heterogeneous group of fatal neurodegenerative disorders including human Creutzfeldt-Jakob disease, bovine spongiform encephalopathy, ovine scrapie, and chronic wasting disease of North American deer and elk. Polymorphisms in the PrP gene are associated with variation in relative susceptibility, pathologic lesion patterns, incubation times, and clinical course of TSEs of humans, mice, and sheep. Homozygosity for codon 129 Met or Val, and in particular Met/Met homozygosity, predisposes exposed individuals to some forms of Creuzfeldt-Jakob disease. The objective of this study was to determine whether homozygosity for Met/Met at the corresponding codon (cervid codon 132) is associated with chronic wasting disease in Rocky Mountain elk. Codon 132 Met/Met homozygotes were over-represented in both free-ranging and captive CWD-affected elk when compared to unaffected control groups.