DNA Test for Degenerative Myelopathy Test
There is now a DNA test for Degenerative Myelopathy!!!–the cost is $65.00 (free if dog is symptomatic).
Scott Kellogg DVM
Dr Joan Coates & Dr Gary Johnson & associates, (University of Missouri), in collaboration with Drs Claire Wade & Kirsten Lindblad-Toh & associates, (Broad Institute at MIT), have identified a mutation that is the primary risk factor for Degenerative Myelopathy (DM) in many breeds of dogs. DM is a spinal cord deterioration with clinical symptoms appearing in older dogs (8 years and over, typically). The first symptoms typically observed are dragging of the hind toes and hind limb weakness, progressing over several months to muscle wasting and a complete loss of control of hind limbs, at which point most owners opt for euthanasia for their dog.
The mutation was discovered in Boxers and Pembroke Welsh Corgis, and has now been shown to be present in over 50 breeds. Not all of these breeds have reported clinical symptoms in older dogs, but we have confirmed the disease using our most stringent criteria in 8 breeds now. To confirm DM and add a breed to our “recommended for testing” list, we first confirm 1) clinical symptoms, 2) DNA test result of AFFECTED/AT RISK, and 3) microscopic changes in the spinal cord typical of DM; and we confirm all 3 conditions in the same individual dog. These conditions have now been met for Kerry Blue Terriers, and the breed has been added to our “recommended for testing” list.
The DNA test is available through the Orthopedic Foundation for Animals (OFA), and can be ordered online using their new Online Store. The test clearly shows dogs who do not have the mutation (normal), dogs who have one normal copy of the gene and one mutated copy of the gene (carrier), and those dogs with 2 mutated copies of the gene (affected/at risk). It is important to understand that not all dogs testing “at risk” will develop clinical symptoms of DM within their lifetime.
Additional research is underway to develop a method for determining more precisely which dogs with the “at risk” genetic profile will remain symptom-free and which dogs will develop clinical disease. However, breeders can use the DNA test as they plan litters to reduce the chances of producing puppies who will be at risk for DM in the future. As of 1-9-09, we have DNA-tested 153 KBT’s for the DM mutation. Seven of these dogs did have DM symptoms and the samples were submitted for DM research by their owners or their neurologist, and all of these dogs did test AFFECTED/AT RISK. The remainder of the dogs tested were chosen at random from KBT samples in the U of MO collection for any reason (DNA bank, or other research projects). Of these 153 dogs, 70 tested NORMAL, 54 tested CARRIER, and 29 tested AFFECTED/AT RISK.
We recommend breeders test their breeding stock for the DM mutation, and include knowledge of the test result in the overall decision-making process when choosing breeding partners. With careful and wise use of the test, overall risk of DM can be reduced while retaining the essential good qualities of the breed.
For additional information on the disease, discovery, research, and recommendations, please see the information on our website. Go to www.CanineGeneticDiseases.net, in the DEGENERATIVE MYELOPATHY section. As outlined in the RESEARCH and SAMPLE SUBMISSION portions of the website, any dog that is symptomatic for DM will be tested at no charge. For general screening of any dog, including breeding stock and other young, healthy dogs, testing kits can be ordered through OFA. Go to www.OFFA.org, scroll down below the cardiac testing announcement and follow the DNA TESTING links to order the kit.
If there are additional questions not answered by the website, please contact me. We hope that this news will be shared with the entire KBT community, and that development of this test will be seen as an opportunity toward improved overall health for the breed.