In collaboration with Dr. Gary Johnson at the Animal Molecular Genetics Laboratory of the University of Missouri and Drs. Claire Wade and Kerstin Lindblad-Toh at the Broad Institute of MIT/Harvard, we have identified a DNA mutation that is a major risk factor for development of degenerative myelopathy (DM) in dogs.  A publication is pending review.  A DNA based test is currently available and information for the test can be obtained at www.caninegeneticdiseases.net. We suspect the high risk mutation to be of autosomal recessive inheritance with incomplete penetrance. The test that is being offered is a diagnostic test from the standpoint that if the result is normal or carrier, the dog is highly unlikely to have DM and diagnostics to determine the cause of the observed clinical signs still need to be pursued.  If the dog tests homozygous affected, then it is at risk for developing clinical signs of DM at some point in its lifetime.  An affected result can support a diagnosis of DM based on clinical signs.  Thus far, all dogs with histopathologic diagnosis of DM have tested affected.  Dogs that have had clinical signs for DM and normal myelogram or MRI also have tested affected.  Since not all dogs genetically at risk will develop DM, clinical signs observed in a patient may be due to other disorders that can mimic DM, such as Type II intervertebral disc disease.  Thus, the clinical signs observed may not yet be due to DM.  In these cases, clinical judgment would need to be used for diagnosis and choice of appropriate treatment based on progression of clinical signs, imaging results and other diagnostics. The test is also available for breeders to reduce the risk of DM in future generations.  We have provided information explaining how to interpret the test results on the website.

While this mutation identifies dogs at risk for developing DM, our research continues in an attempt to identify which dogs will become symptomatic.  We are pursuing studies to identify possible genetic modifiers or triggers for expression of clinical signs. Dogs that are presumptively diagnosed with DM by a veterinarian or veterinary neurologist are eligible for a free DNA test while the study is ongoing.  A blood sample (EDTA whole blood) will need to be sent.  Complete instructions and forms are in the RESEARCH Section of our DM Website located at www.caninegeneticdiseases.net. In addition, we are particularly interested in the nervous system from dogs with presumptive DM for further study.  We have confirmed DM by histopathology in several breeds and are interested in confirming this disease in any breed where it may occur.  Forms to further assist with this part of the study are located also in the RESEARCH Section of the website.