Chondrodysplasia test for Norwegian Elkhounds

Canine genomics research group in the University of Helsinki and Folkhälsan has recently identified a novel mutation for chondrodysplasia in Norwegian Elkhounds. Chondrodysplasia is caused by developmental defects in the ossification of bones and vetebrae in the elkhounds. Affected dogs are dwarfs and about 10-15 cm shorter than their normal siblings.

According to the study the disease is inherited in an autosomal recessive way. Parents carry a single copy of the mutation and on avarage 25% of the puppies are affected, 50% carriers and 25% free of mutation. Dogs who are homozygotes for the mutation are affected. Carriers (only one affected chromosome) are normal. A screen of about 200 Norwegian Elkhounds in Finland indicate that 20% of the population carries the mutation.

The new DNA test enables to identify normal, carrier and affected dogs from blood or cheek swab samples. The test is a tool to help breeding programs to reduce the frequency of the mutation and to keep the carriers in the breeding since the breeder can choose a mutation-free partners. This could be important for the maintenance of the genetic diversity and to allow to breed carriers that have, for example, otherwise superior hunting skills.

Chondrodysplasia has been described in many breeds and there are many genes that affect ossification and bone development. If your dog is free of mutation but has had short-legged puppies we ask you to contact our customer service. So far all the tested short-legged Norwegian elkhounds have been homozygous for the identified mutation and it is likely that the possible disparity may be due to pedigree errors. However, we are interested in the possible exceptions in order to know if there are other possbile genes related to the chondrodysplasia in the breed.

The results are reported as follows:

NORMAL: The dog carries two copies of the normal gene and will not pass over the mutation to its offspring.

CARRIER: The dog carries one mutant and one normal copy of the chondrodysplasia gene and will not develop the syndrome but can pass over the defect to approximately 50% of its offspring.

AFFECTED: The dog carries two mutant copies of the gene and is born as a short-legged dwarf.

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References:

Kyöstilä K ja Lohi H. Manuscript in preparation.

Bingel SA and Sande RD. Chondrodysplasia in the Norwegian Elkhound. Am J Pathol, 107:219-229.