A DNA Test for NCL in Tibetan Terriers is Available NOW!!

January 28, 2010 - updated February 11, 2010
University of Missouri, College of Veterinary Medicine

 

A mutation responsible for the development of Neuronal Ceroid Lipofuscinosis (NCL) in Tibetan Terriers has been identified by a team of researchers led by Dr Gary Johnson and Dr Martin Katz at the University of Missouri-Columbia. A DNA test for this mutation is now available through the Animal Molecular Genetics Laboratory (AMGL) at UM-C, and through a partnership with the Orthopedic Foundation for Animals (OFA).

The NCL’s are a group of neurodegenerative diseases well known in Tibetan Terriers and several breeds of dogs, as well as humans (includes Batten’s Disease, Kufs Disease, and others). All the NCL’s cause a loss of function in the brain and nervous system accompanied by a build-up of storage granules in the nerve cells. There are different types of NCL known in different dog breeds, with varying ages of onset, slightly different presentation of symptoms, and speed of progression to complete debilitation of the affected individual. Our research group previously identified NCL mutations in English Setters, American Bulldogs, and Dachshunds, and a NCL mutation in Border Collies was discovered in Australia.

NCL in Tibetan Terriers is an adult-onset disease, with symptoms typically first appearing at 4-6 yrs of age, and progressing to death or euthanasia by age 7-10yrs. Symptoms seen in Tibetan Terriers include changes in temperament (becoming aggressive, anxious, nervous), uncoordinated gait, loss of training and recognition skills, impaired vision under dim light conditions, and may include mild to severe seizures, especially in the later stages.

Research at the University of Missouri has led to identification of a DNA mutation that identifies which dogs are at risk for developing NCL as they age. This test has been validated using DNA from over 175 dogs known to be clinically normal (no NCL symptoms reported) and more than 40 dogs known to be clinically affected. Twenty-five of these clinically affected dogs were confirmed NCL-affected by examination of tissues submitted after euthanasia. In every case the test result was consistent with the status of the dog with relation to disease signs and relationship to affected dogs. The direct DNA test (this is not a linked marker test) being offered 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 NCL 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 NCL, while still retaining many other desirable traits in their dogs.

TESTING TIBETAN TERRIERS FOR NCL

Breeders and individual owners are now able to test their dogs using the testing kit which 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 AMGL at the University of Missouri, with results reported directly to the owner by OFA. PLEASE NOTE: this test IS now available through OFA, as of Feb 11, 2010!

Owners who had submitted samples for research prior to January 20, 2010, may request test results for their dogs using the Test Request Form for existing samplesclick here for this form. Please note: samples collected by cheek swab for PLL or other testing through OFA do not qualify for this "already banked sample" discount. The cheek swab collects enough DNA to run a test, but not enough to bank for future use.

Owners of dogs (of any breed) that are exhibiting clinical symptoms of NCL and have been diagnosed by a veterinarian or veterinary neurologist as suspected to be affected with NCL are eligible to receive a free DNA test if they send a blood sample, pedigree copy, and complete the symptom survey included with our submission form – click here for the instructions and form to submit samples from affected dogs.

To order multiple DNA tests for the same dog from OFA, after entering the order for one test and there will be a option to order a second test for the same dog (and other choices as well). OFA will send a kit for each test, and each has a seperate barcode - seperate cheek swab samples will need to be collected for each test. Multiple test discounts are not available with the OFA orders. Owners willing to send a blood sample directly to the AMGL can request multiple tests with the order, and receive a discount. Click here for instructions and the multiple-test order form.

Our thanks to the Tibetan Terrier Club of America 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 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.