Chondrodysplasia / CDPA / short-legged phenotype (FGF4L1-related) - Dog

What does this test examine?

This genetic test analyses the FGF4L1 retrogene insertion on chromosome 18 in dogs. The trait is described as chondrodysplasia, CDPA, FGF4L1-related chondrodysplasia, short-legged phenotype or disproportionately short-legged build.

What does this mean for the dog?

The FGF4L1 insertion influences limb development and skeletal growth. Dogs with one or two copies of this insertion have the genetic basis for shorter legs and a relatively longer body. The final appearance can differ between breeds and can also be influenced by other body-shape and coat-colour genes. This CDPA test is mainly used to distinguish the FGF4L1 variant on chromosome 18 from other short-legged variants.

Practical value of this test

• The result helps breeders and owners understand whether short-legged build is explained by the tested FGF4L1 insertion.
• The test supports targeted breeding selection for body shape, breed planning and expected conformation of offspring.
• In dogs with uncertain body type, the analysis distinguishes clear, one-copy and two-copy results for the insertion.
• In skeletal trait panels, this result can be used together with other FGF4 or chondrodysplasia variants.

Inheritance and result

FGF4L1-related CDPA acts as an autosomal incomplete dominant trait. A dog with N/N does not carry the insertion, N/FGF4L1 carries one copy and FGF4L1/FGF4L1 carries two copies of the tested insertion.