UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory
Elk CWD codon 132

Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy (TSE) of elk and other cervids in North America. Other TSE diseases include scrapie and bovine spongiform encephalopathy (BSE). CWD is characterized by weight loss, dehydration, behavioral changes, a rough dull coat and excessive salivation.

SUBMISSION FORM -Allow 2-6 business days for test results.

Detailed CWD Information

CWD infection causes the normal cellular prion protein (PrP) to be converted to an abnormal form. This conversion of the PrP initiates the disease process. DNA sequencing of the PrP gene in elk has shown a single base difference at codon 132. This genetic difference among animals changes the amino acid from methionine to leucine and appears to affect susceptibility or incubation time of disease. Testing of elk for codon 132 of PrP may help breeders to select for animals that are less susceptible to CWD. Below is a summary of the results of the test and the susceptibility status.

Codon 132 Testing

Breeders should be aware that only 1% of the elk tested are L/L for codon 132.

Genotype Description
M/M 2 copies of methionine = susceptible
L/M 1 copy of methionine and 1 copy of leucine = susceptible*
L/L 2 copies of leucine = resistant**

Additional Information

Hamir, A.N., T. Gidlewski, T.R. Spraker et al. 2006. Preliminary observations of genetic susceptibility of elk (Cervus elaphus nelsoni) to chronic wasting disease by experimental oral inoculation. Journal of Veterinary Diagnostic Investigation 18:110-114.

* Research findings suggest that L/M elk have a longer incubation period before clinical signs are evident

** Research findings suggest that L/L elk are resistant to CWD; there has been only one confirmed case of CWD in an animal that tested L/L


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