The results of the ABCA funded Genome Wide Association Study (104 epileptic dogs; 104 healthy dogs; 174,000 marker gene chip) found no region in the genome associated with epilepsy in Border Collies (no test is possible). The genetic component of epilepsy in Border Collies is complex (multiple genes) enough that Dr Mark Neff believes it cannot be selectively bred out of our gene pool. Based upon the study results, my personal recommendation is to not repeat a cross that produced epilepsy but there is no evidence to support removing the sire and dam from the breeding population.
The test data (already paid for) from the 204 dogs can be "mined" for other genetic factors (behavioral, health, physical, etc); all that is needed is an assignment of each dog for the new factors of interest (i.e. strong eye vs weak eye; wide running vs tight running, etc). We will be working with Dr Neff on a list of possible factors for more Genome Wide Association Studies using the data we have.
Dr Neff has previously reported finding a chromosomal region associated with EOD but that the Genome Wide Association Study data could not identify the exact location of the mutation responsible (required to develop an EOD test like the one for CEA). He has 10 likely locations for the mutation. He has proposed a risk test where dogs that have two copies of the normal genes at all 10 sites are not likely to go deaf; dogs that have 2 copies of the mutated genes at all 10 sites are likely to go deaf; and dogs with 1 normal and 1 mutated gene at all 10 sites are likely carriers. Those dogs that have different gene sets at the 10 sites could be used to determine which of the 10 sites has the gene responsible for EOD; this information could lead to the development of a EOD test like the CEA test. Dr Neff is working on a process to provide sample kits (for a suggested donation of about $40) and to collect the required information. He will be interested in testing key dogs (ones from affected lines).
The clinic study for BCC was completed last year; for no additional cost the researchers have been able to initiate a Genome Wide Association Study from the DNA sample they collected as part of this study. Results should be available later this year.
This summary was provided at last night's ABCA meeting.