From: Liz Hansen, reporting on the glaucoma research project headed by Gary Johnson, DVM, PhD at the University of Missouri-Columbia, College of Veterinary Medicine.

Researchers are delighted to report that a vastly improved mapping technology tool is now available! The “SNP Chip” which radically increases the speed at which samples can be processed and mapped, is due from the manufacturer the second week in June. As only one company is producing these chips and demand far exceeds supply, the Missouri researchers have entered into collaboration with Dr. Hannes Lohi in Finland. He will be “running” samples sent from here as well as the European samples submitted to him. It is anticipated that this run will identify the location where the actual mutation should be found with future procedures. Liz likened the process to looking for an address with Mapquest: One starts with the whole world — the total canine genetic makeup — and continue to zoom in — to a country, a state, a city, and finally to the precise street.

The goal remains to find a genetic marker for the expression of glaucoma which would identify whether Dandies are clear, carriers or affected. She emphasized that it is crucial, particularly in a small gene pool, that carriers and affected dogs remain in the breeding population. Without sacrificing all the other positive traits in our dogs, with identification and selective breeding, the percentage of affected animals can be steadily reduced overtime. As an example, she discussed recent identification of the marker and a simple test for another eye affliction in a numerically large breed. Running projections following tests on a several thousand dog sample, it was found that 20% of the breed appears clear, 40% carriers and 40% affected. Obviously, removing nearly half of the population for one disease would be disastrous. The scientists recommend that as above, these animals remain in the breeding population: by continued selection to maintain all other qualities of the breed and slowly moving away from affected dogs in breeding, she projected an essentially clear population could be achieved in about 20 years, roughly ten generations. In regard to Dandies, one must surmise this would take somewhat longer, but still a short period compared to the breed’s long history.

The project still is in great need of samples, particularly of affected dogs plus their normal relatives (siblings and parents). Collecting such data has been a problem as the majority of cases of glaucoma in the breed are late onset, with littermates scattered and parents dead. Ms. Hansen suggests that samples from litters sires and dams where glaucoma shows in the pedigree behind them would be very appropriate, as a change in any dog’s condition can be reported at a future date. For full information on the project and how to submit samples, go to the website: www.caninegeneticdiseases.net Specific questions about sample and pedigree submission may be sent to hansenl@missouri.edu or devorej@missouri.edu.

Cathy Nelson