U researchers ID mutant gene in Labradors

Over the past two months, Labrador breeders from all over the United States and Europe have been sending blood samples to the University, where, for the first time, they can find out if their Labrador retrievers are among the 30 percent that carry a gene linked to Exercise Induced Collapse .
A University study released Sunday details the identification of a mutant gene in Labrador retrievers that is strongly associated with EIC, which affects an estimated 3 to 5 percent of Labradors .
It’s the first time a naturally occurring mutation of this particular gene, known as dynamin 1 , has been identified in a mammal, lead author and University veterinarian Ned Patterson said.
The symptoms of EIC — wobbliness and eventual collapse of the rear legs — are generally brought on by intense exercise and excitement from activities like hunting. In some instances, loss of muscle control spreads to the front legs and, in rare cases, has caused death, though most dogs recover quickly.
The gene produces a protein involved in the chemical signaling between nerves that allows the brain to control muscle movement, Patterson said.
He and the study’s co-authors think the mutant protein hinders the system’s ability to send signals between nerves. This suggests that EIC occurs because the chemical communication system can’t keep up with rapid firing required during intense exercise, he added.
Now that they’ve linked the mutant gene and the disorder, he said, they’re doing more research to confirm that the mutant gene does, indeed, affect the nervous system in this way.
He added that since all mammals carry the gene, learning more about how the gene’s protein functions could contribute to understanding disorders in other mammals, including humans.
Prior to this study’s findings, diagnosing the syndrome was a challenge, because they first had to rule out other possible causes of collapse and were never completely certain of a diagnosis, he said.
Now, a DNA blood test can confirm diagnosis for breeders and owners whose Labradors are exhibiting symptoms, Patterson said.
The cost of the test is $65 — within the range of other blood work done on dogs, he added.
Breeders can also find out if their dogs carry the mutant gene, he said.
“Almost always, they need two bad copies of the gene to be affected,” he said, so breeders can make sure they don’t produce an affected dog.
Brett Bunk, a Missouri breeder , said he’s already used the test on three dogs and found out one of the male dogs is a carrier. He said he plans to use the test to make sure he doesn’t breed that dog with a carrier female.
Test to be available exclusively through U lab
Patterson said he and the study’s co-authors have submitted a patent for the test and plan to make the University’s Veterinary Diagnostic Lab the exclusive license holders, at least in the United States.
However, he pointed out that until the patent is granted — likely within the next year -— other labs could use the test. He didn’t want to wait for the patent to be granted to get the study results out to the public, he said.
The patent would be good for the next 20 years, John Merritt , director of the Office of the Vice President for Research, said.
James Collins , director of the diagnostic lab, said it’s common for researchers to patent genetic tests.
“As we’re looking for ways to get new revenue, patents and licensing is just one of the things that’s required,” he said.
As state and federal funding for higher education has fallen, it has been necessary for Universities to protect their intellectual property, he said.
He anticipates the test will be a significant source of revenue for the diagnostics lab, and a good situation for the veterinary school, the University and the inventors, he said.
Since the first blood sample was submitted to the lab on July 17, they’ve run 1,525 tests for the mutant gene, Collins said. Most samples have come from breeders throughout North America and Europe, he added.
“Anybody in the world who can access us by FedEx or other courier has access,” he said.