Chondrodystrophy with Intervertebral Disc Disease (CDDY/IVDD)
Intervertebral Disc Disease (IVDD) is a disorder characterized by rupture of the discs in the spine that act as cushions between the bone of the vertebrae that encase the spinal cord. Rupture of the discs puts pressure on the spinal cord causing neurologic signs which can range from a wobbly gait, neck and back pain to paralysis in extreme cases. The onset of disease signs usually occurs in adulthood. In some breeds, the presence of this insertion is also associated with short-leggedness. A hereditary form of IVDD is associated with the insertion of a version of the FGF4 gene on chromosome 12 (12-FGF4R).
Breeds affected: IVDD associated with the 12-FGF4R variant occurs in numerous breeds including Bassett Hound, Beagle, Bichon Frise, French Bulldog, Cardigan Welsh Corgi, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Chihuahua, Chinese Crested, Cocker Spaniel, Coton de Tulear, Dachshund, Dandie Dinmont Terrier, English Cocker Spaniel, English Springer Spaniel, Havanese, Nova Scotia Duck Tolling Retriever, Pekingese, Pembroke Welsh Corgi, Poodle, Portuguese Water Dog, Russell Terrier group, Scottish Terrier and Shih Tzu.
References: Brown EA, Dickinson PJ, Mansour T, Sturges BK, Aguilar M, Young AE, Korff C, Lind J, Ettinger CL, Varon S, Pollard R, Brown CT, Raudsepp T, Bannasch DL. FGF4 retrogene on CFA12 is responsible for chondrodystrophy and intervertebral disc disease in dogs. Proceedings of the National Academy of Sciences of the United States of America. 114(43):11476-11481, 2017.
Batcher K, Dickinson P, Giuffrida M, Sturges B, Vernau K, Knipe M, Rasouliha SH, Drogemuller C, Leeb T, Maciejczyk K, Jenkins CA, Mellersh C, Bannasch D. Phenotypic Effects of FGF4 Retrogenes on Intervertebral Disc Disease in Dogs. Genes (Basel). 10(6), 2019.
Gene: 12-FGF4R
Explanation of DNA Test Results
Normal (N/N)
This dog tested clear for the variant causing IVDD in dogs. It can only transmit a normal gene to offspring and can be bred to a dog that has also tested N/N without producing affected offspring.
Carrier (A/N)
This dog has tested as a carrier for the Varian causing IVDD in this breed. It is at risk for developing the disease, and it may transmit either a normal gene or an affected gene to offspring. To minimize producing affected offspring this dog should only be bred to dogs DNA-tested NORMAL for this mutation.
Affected (A/A)
This dog has tested as affected for the variant causing IVDD in this breed. It is at risk for developing symptoms of the disease. If this dog is bred, it will pass down the risk for developing IVDD to each of its offspring.
For more information on this disorder, please refer to the Canine Genetics Laboratory website https://cvm.missouri.edu/research/canine-genetics-laboratory/
Tests are ordered online through the secure area of the OFA website. Payment is accepted by credit card (MasterCard and VISA). The OFA administers all order handling. Upon receipt of an order, the OFA will send out the test kit which will include a Foam-Tipped Applicator card for DNA sample collection, along with sample collection instructions. Using the FTA card technology, owners can safely collect DNA samples at home. The collection process is non-invasive, and no veterinary appointment is necessary.
Samples are then sent to the University of Missouri College of Veterinary Medicine where the samples will be processed by the Small Animal Molecular Genetics Lab. Results will be forwarded to the OFA, and the OFA will issue the resulting report to the owner.
The fee for each test includes the test kit, laboratory processing, and subsequent registration in the OFA databases.