The region of the genome where the mutation is located has been conclusively identified (this was reported at the VA finals). The region is 3 million base pairs in the 2500 million base pair canine genome.
The next set of tests they ran typically reveals the exact location of the suspected mutation and with this information they can develop a test.
What actually happened is the next set of experiments was not able to find the exact location of the mutation.
They proposed reasons why they were not able to identify the exact location of the mutation; the most likely is related to the current state of the genetic testing technology and the exact size a location of the mutation. Additional (costly) experiments are being evaluated (in terms of likely success and/or possible benefit to breeders) as a means to aid in locating the mutation; meanwhile, genetic testing technology continues to improve.
Thanks for the info Mark. So, in "layman" terms? It's a mutation but they can't find where it's coming from (and won't be able to until genetic testing improves). So ... does that mean it's like the lottery (the losing kind :@( where it just turns up because something mutates? Both parents have it or they just don't know?
Thanks for keeping up with this ... it's frustrating for people to put so much time/effort/energy into their dogs and have them go deaf just when they are trained.