University of Missouri researchers believe both man and animal will benefit from their discovery that the same gene mutation found in Tibetan terriers can also be found in a fatal human neurological disorder related to Parkinson’s disease.

Fabiana Farias, a doctoral candidate in Area Genetics at the University of Missouri, found the mutation as part of her thesis research. The disease in Tibetian terriers is called adult-onset neuronal ceroidlipofuscinosis (NCL). Within the dogs’ cells in the brain and eye, material that should be “recycled” builds up and interferes with nerve cell function. Due to this buildup, around the age of five years old, the dog begins to exhibit dementia, impaired visual behavior, loss of coordination, and shows unwarranted aggression.

While there are many forms of NCL in humans, the symptoms are similar in people and dogs, and the disease is ultimately fatal for both. Utilizing the canine genome map and DNA samples from dogs diagnosed with NCL, the researchers were able to pinpoint the specific gene that causes NCL. The mutation they discovered in dogs, however, causes a hereditary form of Parkinson’s disease in humans. This suggests that the recycling that goes awry in NCL may also be involved in degenerative diseases like Parkinson’s.

Now, DNA from dogs can be tested to identify the presence of the mutated gene, and that test can ensure that Tibetan terrier breeders do not pass it on to the next generation. The researchers also believe they may be able to test potential human therapies on the animal population because they can use the DNA test to identify affected dogs before they start to show symptoms.