September 1, 2009
University of Missouri, College of Veterinary Medicine

A mutation responsible for the development of lens luxation in many breeds of dogs has been identified by a team of researchers led by Dr Gary Johnson DVM PhD and Dr Elizabeth Giuliano DVM MS ACVO at the University of Missouri College of Veterinary Medicine. A DNA test for this mutation is expected to be available by late September 2009 through a partnership with OFA (Orthopedic Foundation for Animals).

Lens Luxation is an eye problem well known in many Terrier breeds, Tibetan Terriers, Chinese Cresteds , Australian Cattle Dogs, and other breeds. The lens is held in place in the eye by fibers known as zonules. If these zonules break or disintegrate, the lens can fall out of place, or luxate. When this happens it often requires immediate veterinary attention to remove the displaced lens, or the entire eye. Lens luxation can cause a secondary glaucoma, which also leads to pain and loss of vision.

Research at the University of Missouri has led to identification of a DNA mutation that predicts which dogs are at risk for developing lens luxation as they age. A simple DNA test will reveal if a dog is NORMAL (has 2 normal copies of the gene), a CARRIER (has one normal copy and one mutated copy of the gene) who will not develop lens luxation but could pass the mutation on to offspring, or AFFECTED/AT RISK (has 2 mutated copies of the gene). Wise use of this test will allow breeders to avoid producing individuals destined to develop lens luxation, while still retaining many other desirable traits in their dogs.

Breeders and individual owners will be able to test their dogs using the testing kit that can be ordered online through the OFA website (www.OFFA.org). DNA is collected using a cheek swab, and the barcoded sample will be tested by the Animal Molecular Genetics Lab at the University of Missouri, with results reported directly to the owner by OFA. PLEASE NOTE: this test is not yet online at OFA, but should be available by the end of September 2009. This website will be updated with an announcement as soon as the test is online at OFA.

Owners who had submitted samples for research prior to Sept 1, 2009 may request test results for their dogs using this Test Request Form for existing samples – click here for this form. These requests will be accepted now.

Owners of dogs that have been diagnosed as affected with lens luxation by an ACVO ophthalmologist are eligible to receive a free DNA test if they send a blood sample, pedigree copy, and a copy of the ophthalmologists report – click here for the instructions and form to submit samples from affected dogs. Samples from affected dogs may be sent now as well.

Testing for all other dogs will be available through OFA shortly – we will update this announcement as soon as it is online on the OFA website.

Our thanks to the clubs and many individual owners who have supported this research and participated in the project by supplying samples and information on their dogs, as well as monetary support. We also appreciate support from the Jack Russell Terrier Club of America, and past support from the Canine Health Foundation for the early stages of this research. Please watch this space for updates in the next few weeks. If you have questions, you may contact Project Coordinator Liz Hansen at [email protected].

http://www.caninegeneticdiseases.net/GLX/mainGLX.htm