Two separate genetic variants are detected with this test, and will be reported separately.
- Chondrodystrophy (CDDY) with risk of IVDD associated with the FGF4-12 retrogene insertion.
- Chondrodysplasia (CDPA) associated with the FGF4 -18 retrogene insertion
Chondrodystrophy (CDDY) with risk of IVDD
Chondrodystrophy (CDDY) in dogs is defined by dysplastic (abnormal), shorted long bones (short legs) and premature degeneration and calcification of intervertebral discs. Chondrodystrophic breeds are prone to a type of disc degeneration called chondroid metaplasia, where the discs become hardened and less able to flex with movement and therefore more prone to bulging or rupture i.e. Intervertebral Disk Disease (IVDD). The calcified inner disc material also puts pressure on the spinal cord, causing pain and damage to the nerves running through the spinal cord. Dogs may suffer from severe pain, inability to urinate or defecate, paralysis and even death. Many affected dogs are treated by surgically removing the prolapsed disc.
A partial copy of the FGF4 gene has been inserted (FGF4-12, a retrogene insertion) on chromosome 12 and is associated with CDDY. Evidence that suggests that any dog with one or two copies of FGF4-12 will be affected with CDDY, will have short legs and will be predisposed to IVDD. However, not all dogs with FGF4-12 will go on to develop IVDD.
Chondrodysplasia (CDPA) is shortened long bones, resulting in dogs with short legs.
A partial copy of the FGF4 gene has been inserted (FGF4-18, a retrogene insertion) on chromosome 18 and is associated with CDPA. Evidence that suggests that any dog with one or two copies of FGF4-18 will have short legs. Unlike CDDY, CDPA is not associated with any disease.