La chondrodystrophie (CDDY avec risque d’IVDD)

Short legs in dogs can be caused by two mutations in the functional fibroblast growth factor 4 (FGF4). This gene is crucial in biological processes, including bone development. The mutations are found on chromosome 12 (FGF4L2) and 18 (FGF4L1).

The mutation analysed in this test is the one found on chromosome 12, which leads to Chondrodystrophy (CDDY). Chondrodystrophy (CDDY) is a semi-dominant trait that is characterised by a short-legged phenotype: Dogs with 2 copies of the mutation are smaller than dogs with only 1 copy, that are already smaller than unaffected dogs.
 
The same mutation can also lead to degeneration of intervertebral discs, which means that dogs with the mutation are more susceptible to Hansen’s type I intervertebral disc disease (IVDD). IVDD follows a dominant mode of inheritance, meaning that 1 copy of CDDY mutation is already increasing the risk of developing IVDD.

This disease has been found in many different breeds, particularly breeds with short legs and/or long backs, including Dachshunds, Corgis, Basset Hounds, Beagles, Cardigan Welsh Corgis, Cavalier King Charles Spaniels, Chesapeake Bay Retrievers, Chihuahuas, Chinese Cresteds, Cotons de Tulear, Dandie Dinmont Terriers, English Springer Spaniels, French Bulldogs, Havanese, Nova Scotia Duck Tolling Retrievers, Pekingese, Miniature Poodles, Toy Poodles, Scottish Terriers, Shih Tzus, Jack Russell Terriers, and American Cocker Spaniels.