JRD - Page 2

The degree of Kidney damage caused by Renal Dysplasia (RD) varies from carrier to carrier. In much the same way as Hip Dysplasia (HD) varies from affected dog to affected dog. With hips scores ranging from 0 to 53 for each hip and any dog with a low score up to a high score IS AFFECTED BY HD, and has hip dysplasia to some degree.

RD can be very mild in some carriers and very severe in others and anywhere between. We should all realise that dogs can survive with around 50% kidney function or ONE kidney, in a similar way humans can survive with ONE kidney, which is clearly 50% of our normal TWO kidneys.

Any RD carrier with kidneys that are impaired by RD less than 50% will live quite normally into old age. Those around the 50% may have problems IF they contract an illness or another disease which places increased stress on their kidneys or impairs them further.

For these reasons MANY carriers survive without any signs of the RD disease and without their owners having any clue that they are indeed RD carriers. In a similar way to Hip Dysplasia where the majority of hip scores are below 50% of the maximum total of 106 score, it appears that the degree of kidney damage in the majority of RD carriers is below 50% of their kidneys function. Therefore, thankfully the majority will live normal lives.

The real problems arise for the breeders and owners of RD carriers is first of all with some RD affected puppies being still born, and then those puppies with RD kidney damage close to and over 50% RD kidney damage. These are very likely to die at various ages, from a few months of age up to a few years, and when they are dying through kidney failure (diagnosed or not), there is nothing that can be done to save them. The majority of these deaths will not have been RD DNA tested and will not have been diagnosed as RD carriers, even while they are dying, so therefore most deaths through Renal Dysplasia disease go unrecorded. 

However I am absolutely sure with the availability of the RD DNA Test and the much wider Veterinary and public knowledge of the RD DNA Test, this will change.

In the meantime I sincerely hope more breeders will seriously consider RD DNA testing their breeding stock. I also hope that our GSD breed can avoid the extremely high saturation levels of Renal Dysplasia that several other breeds are suffering with,

I just got an e-mail this week that the RD test results from Doggenes is now being accepted into the OFA database in the US if breeders/owners wish to include those test results.

Dogenes have definitely sorted out the unique problem which arose with the FCR.

Major problems beset many breeders who DNA test and publish their results, especially when they publish "carriers". These problems mainly stem from the abuse  and/or misunderstanding of other breeders and the general public regarding DNA testing in general. They tend to immediately believe an affected dog should be culled, sterilised or banned from breeding. They also tend to taint the affected dogs kennel, its pedigree and all dogs connected with the pedigree in any way, even to ridiculous lengths.

I would strongly urge people only to publish "CLEARS" - this offers the breeders and the public the knowledge as to who and where the "clears" are. With regards to the "carriers" the owners and the breeders normally require/desire confidential independent and knowledgeable advice of what options they may have. This is where major difficulties arise for the owner and breeder, who do they trust is their most significant problem to overcome.

I can't believe what I have just read - only publish the clears?  You have got to be joking!  Surely publishing all results is imperative if people are to get a true picture of the problem.  If the inheritance is as we understand it a carrier mated to a clear will produce possibly 50% carriers, which can be tested to find out which are carriers and which are clear (there should be no affecteds).  This would give the impression that only clears should be bred from and could remove from the gene pool some very good dogs who happen to be carriers and would not produce affecteds if mated to clears. 

I also don't understand your definition of carriers - my understanding is that carriers may pass the disease on but not actually be affected by it - I am wrong in this understanding?

The KC I believe will add the DNA test results to a dog's records if the certificates are submitted.

PARENTS PROGENY

Clear X Clear ALL CLEAR


Homozygous mutant allele X Homozygous mutant allele ALL HOMOZYGOUS FOR THE 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




--------------------------------------------------------------------------------

Notice to the Flatcoated Retriever Society - by DOGenes
As you know DOGenes Inc. has been doing a Genetic test for renal dysplasia in your breed. This research although not funded by your breed was the fortunate result of extensive research in other breeds.

It has now become apparent that a problem existed with the test (NOT THE GENE) due to a variant allele that is so far limited to three breeds. These are the Flatcoated Retrievers, Golden retrievers and Gordon setters.

We were aware of this variant prior to the testing, in a single Gordon setter that was identified in the course of the research behind this test. This was discovered by chance in a DNA sequencing project looking a cross-section of breeds.

At the time at we initiated the testing in your breed we had no clinical association affixed to this allele, so we have reported it as wild type, or clear.

A surprising result was brought to my attention when two clear Flatcoated retrievers were bred, and all of the puppies tested as carrier. In order to investigate this, we did the obvious experiment, which was to confirm the genotype of the parents. New samples were submitted and the results were confirmed.

Therefore it was impossible that the puppies were carriers and the investigation was escalated to determine why this happened. As it turns out, there was an interaction between the wild type allele, and the variant allele described above. This resulted in a molecule that interfered with the interpretation of the results. The test conditions were changed to eliminate this molecule from interfering with the results reporting. An outside independent laboratory confirmed the genotypes of the puppies. All of the puppies were carriers of the allelic variant.

Upon further investigation, we have determined that this variant allele was present in the original clinical sample submitted for analysis. Therefore this variant is now associated with the disease.

Unfortunately this is the nature of research and it is realized that it may be difficult to come to terms with, however we have gained knowledge that will ultimately benefit your breed.

As a result of this technical issue, some of the test results were reported incorrectly. Some of the genotypes from clears and a few carriers will have to be re-assigned.

The new test will have to be done at high resolution and we are trying to settle on a platform to do this, and this is going to slow down the process of re-assigning the genotypes. We are asking you to be patient so that we can move forward. When we are confident that the new test gives unfailing accurate results then we will retest all the DNA samples that were misclassified.

We realize that this has caused stress for the owners of the animals involved, and while it is regrettable that this happened, it is better that this was found early in the testing rather than later.

Addendum: The revised test will detect this allele and all genotypes completely accurately, and the outside lab has also verified this. In other words, they have validated the test.

My post was taken from the current Dogenes website.  Whats the point trying to have a reasonable discussion when your attitude to anyone who questions what you write is so vitreolic?