Identification of Genetic Risk Factors in Degenerative Myelopathy in German Shepherd Dogs

Canine degenerative myelopathy (DM) is an adult-onset neurodegenerative disease that causes a progressive loss of spinal cord function and typically culminates with euthanasia. In the 1970s, DM was considered to be a disease of German Shepherds Dogs. We now know that DM occurs in many other breeds; nonetheless, DM remains a significant cause of disease and premature death in German Shepherd Dogs. In cooperation with the German Shepherd Dog Club of America, Dr. Kerstin Lindblad-Toh, from the Broad Institute, is working to determine if there are as yet undiscovered factors in the genetic background of German Shepherd Dogs that make them more or less susceptible to the development of DM.

Participation Requirements:

Phase 1

Drs. Gary Johnson and Joan Coates at the University of Missouri are assisting Dr. Kerstin Lindblad-Toh with sample collection for this project. In the first phase of this project, they are seeking cheek-swab samples from purebred German Shepherd Dogs that are

1. six years old or older,
2. have not already had a DNA test for the DM-associated mutation, and
3. are free from musculoskeletal disease as indicated by a normal (limp-free) gait.

If you are willing to donate a cheek swab (or blood) sample from one or more of your healthy German Shepherd Dogs, please download and fill out a form for each dog and email them along with a scan of your dog’s pedigree to Liz Hansen (HansenL@missouri.edu) Specifically, we are requesting the following information:

• the dog's birth date,
• the dog's registration number,
• and a copy of the dog's pedigree.

Phase 2

Based on the age and pedigree information provided in the form, we will select approximately 400 dogs that together best represent the entire German Shepherd Dog population. Kits with cheek swabs and instructions for cheek-swab collection will be sent to the owners of the selected dogs. We will isolate DNA from the returned cheek swabs and test for the mutation responsible for degenerative myelopathy. Confidential test results will be emailed, without charge, to the owners of the selected dogs. The results of this first phase of this project will help us fine tune subsequent phases and maximize our chances for finding as yet undiscovered factors in the genetic background of German Shepherd Dogs that make them more or less susceptible to the development of DM.

The DNA from these cheek swabs will be tested for the SOD1 risk allele and used in subsequent experiments to identify genetic factors that modify the ages at onset or the rate of progression of DM in GSD.