English Mastiff a model for human eye disease

Ithaca, N.Y.-The English Mastiff dog breed is enabling scientists to help explain retinitis pigmentosa (RP) in humans.

Researchers at Cornell University and the University of Pennsylvaniahave discovered that this particular breed, which can carry a gene defectfor progressive retinal atrophy (PRA) disease, is the best animal modelof the human eye disease, RP.

"This research will greatly help in finding treatments and curesfor these inherited forms of blindness in humans and eradicating the conditionin dogs," says Gerald J. Chader, M.D., chief scientific officer ofthe Foundation Fighting Blindness, a sponsor of the study.

The dogs may be used to test therapies for the human disease, accordingto researchers at Cornell's Baker Institute for Animal Health and the Universityof Pennsylvania's Scheie Eye Institute.

Up to 100,000 humans in the United States suffer from the disease.

Recently Cornell scientists discovered the genetic mutation of a defectivegene - RHO - which is causing PRA blindness in the English Mastiff. Thestudy was reported in the April 30 Proceedings of the National Academy ofSciences.

Vision researchers had been seeking a large animal model for the humanversion of the eye disease since it was discovered in humans in 1990.

As a result of the research, scientists have developed a genetic screeningtest for dog breeders to help eliminate the defective gene from the lineof purebred dogs.

Sponsors of the study include the National Institutes of Health and theMorris Animal Foundation.