What do the Gordon Setter and Old English Sheepdog have in common?
Both breeds suffer from a type of hereditary ataxia where neurons in the cerebellum that control movement begin to die, causing a gradual loss of coordination. In humans, ataxia is also the 3rd most common neurodegenerative movement disorder (after Parkinson’s and Huntington’s diseases).
Researchers at the National Institute on Aging and the Broad Institute of MIT and Harvard looked at 630 Old English sheepdogs and mapped ataxia genetically in the families of affected animals. Eventually they mapped the disease to a gene, RAB 24, located on chromosome 4. A mutation in RAB 24 was closely associated with development of the disease, and on screening of affected dogs of other breeds, the identical mutation was found in Gordon setters, providing additional evidence that this mutation is important.
“Rab 24 is a protein that is believed to be important to the process of autophagy – which is how cells cleanse themselves of waste,” says North Carolina State neurologist Natasha Olby who collaborated on the research.
“We know that autophagy and neurodegeneration are connected, so pinpointing this protein is important to our understanding of the disease process.”
“We have not yet proven that this mutation causes neurodegeneration; it could simply be a very good marker for the disease,” Olby says. “Our next step will be to determine exactly how the mutation affects the protein Rab 24 and its function and to determine whether this results in neuron death. This gene will also be investigated in humans with hereditary ataxia.”
The findings appear in the journal PLOS Genetics. The research was funded by the American Kennel Club Canine Health Foundation with additional support from the Old English Sheepdog Club of America.