Genetic Testing and Research for Dogs

What your test results mean and how to use them.


Renal dysplasia refers to a developmental defect in the kidney.  In humans and mice there are 100's of genes involved in the process
of kidney development and renal dysplasia is caused by many genes.

This is  likely the case in canines as well and other causative mutations are likely to be discovered.  In the case of the Cox-2 mutations
used for this test the phenotype is clearly defined by the presence of fetal glomeruli as well as other immature structures.

The DNA test results are reported as follows:

a) Clear - No copies a RD mutation are present. - You dog will not get this inherited form of kidney disease.
    This test does apply to other forms of kidney disease or a kidney defect due to a birth defect.

b) Carrier - (your dog has one copy of a RD mutation:  one copy was from either the sire or the dam).
    Your dog is at RISK of developing RD throughout its lifetime. The RISK is however low (3-5%).
    Your dog can still pass this disease on to its progeny.

c) Homozygous for mutant alleles (your dog has two copies a RD mutation : one from the sire and one from the dam).
    Your dog is at RISK of developing RD throughout its lifetime. The RISK is however low (3-5%).
    Your dog can still pass this disease on to its progeny.

With results b and c above, your dog can be used for breeding to help eliminate this disorder from your breeding stock.

Breeding Decisions.

For breeds with a high frequency of a mutant RD mutations:

1. My dog is a clear. Examine this dogs good and bad traits. Can he/she be bred to a carrier in your kennel that can
    complement their traits? Yes. At this time, many breeds with RD have an very high frequency of the mutation, and in
    order to protect the gene pool, this type of breeding is necessary.

    You keep the clear puppy from this cross that has the traits from both parents that you were hoping to get.

2.  My dog is a carrier. Ideally, this animal should be bred to a clear with traits that would complement this animal. -
    Clear progeny from this cross can be kept for future breeding. There is a 50% chance in this case of producing a clear
    in the first generation. If no other options exist, this animal can be bred to another carrier. In this case, your chances
    of producing a clear for your next generation are 25%. Likewise,there is a 25% chance that a animal that is homozygous
    for the mutant allele will be produced from this breeding.

3. My dog is homozygous for mutant alleles, but otherwise is sound in body and temperament, and brings positive traits
    to the breed. This is a two-step breeding to get a clear. This dog should be bred to a clear, if possible. All of the puppies
    in the first generation will be carriers. No need to DNA test at this point. A carrier puppy from the first generation of
    breeding can now be used in the second generation to produce clears as in example 2.

DOWN THE ROAD, your ultimate goal is to breed clear to clear so that you have eliminated RD from your kennel without
having to compromise the gene pool.

Breeding Outcomes:

Clear X Clear ALL CLEAR
Homozygous mutant allele X Homozygous
mutant allele
Clear X Carrier 1/2 Clear : 1/2 Carrier
Carrier X Carrier 1/2 Carrier: 1/4 Clear : 1/4 Homozygous mutant allele
Clear X Homozygous mutant allele All Carrier
Homozygous mutant allele X Carrier 1/2 Carrier : 1/2 Homozygous mutant allele