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Skeletal Dysplasia 2

Skeletal Dysplasia 2 (SD2) is an abnormality of the skeleton that results in mild dwarfism.

Found in

1 in 380 dogs

in our testing

Key Signs

Mild disproportionate dwarfism

Age of Onset

At birth

Present at birth

Inheritance

Autosomal Recessive

For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.

Likelihood of the Condition

High likelihood

At risk dogs are highly likely to show signs of this disease in their lifetime.

What to Do

Here’s how to care for a dog with SD2

Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.

For Veterinarians

Here’s what a vet needs to know about SD2

Affected dogs have shorter limbs, but otherwise normal build. Forelegs are usually slightly more affected than hind legs. Shoulder height is lower (<50 cm) compared to the international breed standard (54-57 cm), which can be observed after the dog’s growth period is finished. In contrast to other skeletal dysplasias, no auditory problems, deafness, or secondary joint problems are associated with SD2. Because the mutation is superimposed on the normal variation seen in the breed, it can be difficult to identify the trait in some individuals.

Though an affected dog may have shortened limbs, the condition is not expected to negatively impact their quality of life.

For Breeders

Planning to breed a dog with this genetic variant?

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to occur. A carrier dog with one copy of the SD2 mutation can be safely bred with a clear dog with no copies of the SD2 mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the SD2 mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Please note: It is possible that disease signs similar to the ones caused by the SD2 mutation could develop due to a different genetic or clinical cause.

Technical Details

Gene COL11A2
Variant G>C
Chromosome 12
Coordinate 2,652,874

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Frischknecht, M., Niehof-Oellers, H., Jagannathan, V., Owczarek-Lipska, M., Drögemüller, C., Dietschi, E., … Leeb, T. (2013). A COL11A2 Mutation in Labrador Retrievers with Mild Disproportionate Dwarfism. PLoS ONE, 8(3). View the article