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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 Gary Johnson DVM PhD 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, Chinese Cresteds ,
Australian Cattle Dogs, Tibetan Terriers, 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. Lens luxation
can cause secondary glaucoma, which also leads to pain, loss of
vision, and sometimes loss of the entire eye.
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 gives breeders a tool to avoid
producing individuals at risk of developing 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.
Owners of dogs that have been
diagnosed as affected with lens luxation by an
ACVO or ECVO boarded ophthalmologist are eligible to receive a
free DNA test if they send a blood sample, pedigree copy, and a
copy of the ophthalmologist's 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 at 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 greatly 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
HansenL@missouri.edu. |