Estimating relative CWD susceptibility and disease progression in farmed white-tailed deer with rare PRNP alleles

PLoS One. 2019 Dec 2;14(12):e0224342. doi: 10.1371/journal.pone.0224342. eCollection 2019.

Abstract

Chronic wasting disease is a prion disease affecting both free-ranging and farmed cervids in North America and Scandinavia. A range of cervid species have been found to be susceptible, each with variations in the gene for the normal prion protein, PRNP, reportedly influencing both disease susceptibility and progression in the respective hosts. Despite the finding of several different PRNP alleles in white-tailed deer, the majority of past research has focused on two of the more common alleles identified-the 96G and 96S alleles. In the present study, we evaluate both infection status and disease stage in nearly 2100 farmed deer depopulated in the United States and Canada, including 714 CWD-positive deer and correlate our findings with PRNP genotype, including the more rare 95H, 116G, and 226K alleles. We found significant differences in either likelihood of being found infected or disease stage (and in many cases both) at the time of depopulation in all genotypes present, relative to the most common 96GG genotype. Despite high prevalence in many of the herds examined, infection was not found in several of the reported genotypes. These findings suggest that additional research is necessary to more properly define the role that these genotypes may play in managing CWD in both farmed and free-ranging white-tailed deer, with consideration for factors including relative fitness levels, incubation periods, and the kinetics of shedding in animals with these rare genotypes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles*
  • Animals
  • Deer / genetics*
  • Disease Progression*
  • Genetic Predisposition to Disease / genetics*
  • Prion Proteins / genetics*
  • Wasting Disease, Chronic / genetics*

Substances

  • Prion Proteins

Grants and funding

This work was supported by the North American Deer Farmers Association (https://nadefa.org/) to NH and Whitetails of Wisconsin (https://www.whitetailsofwisconsin.com/) to NH. Simpson Whitetails Genetic Testing provided support in the form of salaries for authors (DS and AC), as well as genotypic data from a subset of CWD negative herds, representing approximately 50% of the healthy herds reported. These authors had no role in study design or data analysis. The specific roles of these authors are further articulated in the “author contributions” section.