As a result of recent communication from the researchers, it has been decided to suspend the testing requirements for ERD and Von WIllebrand’s Type 11 from the Code of Ethics forthwith.
This is based on the information below.
Mars Veterinary and Genoscoper have completed the extensive evaluation of the early retinal degeneration (erd) mutation test, and wanted to reach out to the Norwegian Elkhound community to provide an update regarding our findings. In so doing, we hope to also help clarify the situation and address any concerns that have come to light in the interim.
For the benefit of those who may read this and who are not aware of what has transpired, we would like to mention that the erd mutation test was based on an eye disorder phenotype originally characterized in a 1987 journal article. The assay we created was based on this characterization and subsequently incorporated into the latest version of our genotyping chip. Once the new chip was operational, the erd assay was used to examine for the occurrence of this mutation in the tested population. Prior to incorporating this particular mutation into the Optimal Selection™ test in the United States, Mars Veterinary and Genoscoper conducted a secondary validation on a subset of samples (non-Elkhound) whose initial results suggested a possible carrier status. The purpose of the secondary validation was to use a secondary technology platform to verify that the assay was in fact identifying the actual, documented mutation and is part of the normal quality control processes we employ. This validation process included the sequencing of these samples and the subsequent evaluation of the resulting DNA sequences against the expected mutation sequence. Such validation efforts are vital in allowing both Mars Veterinary and Genoscoper to continually drive product improvement and scientific knowledge. The result of this sequencing project did not find the mutation variant in any of the sequenced samples which were deemed possible carriers.
Consequently, to date, we have seen limited to no evidence that would support the erd mutation’s presence in the natural dog population or within the Norwegian Elkhound breed. Our experience is supported by the investigation conducted by Dr. Acland, which you were kind enough to share with me, where he concluded that none of the tested British Norwegian Elkhounds carried the erd mutation, and that their PRA was instead caused by the common prcd-PRA mutation found in multiple breeds.
It is possible that the erd mutation, originally characterized in a research colony established from two erd-affected dogs that were highly inbred siblings, does not exist outside of the discovery line(s) any longer.
Hence, because suspected carriers have not been confirmed on secondary analysis, the work of others supports its eradication from the natural population, and the original characterization suggests that the problem may have been limited in extent, we feel that continued inclusion of the erd mutation in the MyDogDNA panel is misleading and that it should not be a primary contributor to breeding decisions within the Norwegian Elkhound population. For these reasons, we have decided to discontinue reporting the erd mutation in our commercial product at this time. We would be happy to re-evaluate the situation, should you be able to help us in identifying samples from known erd-carrier or affected dogs for analysis at our laboratory. We will naturally maintain monitoring for the erd mutation for research purposes as well, and inform you immediately if the situation changes. However, the currently available information supports its discontinuation and we feel that is the most ethical option in helping the Norwegian Elkhound community.
Finally, we are happy to inform you that we will soon be able to offer you the prcd-PRA test, known to be relevant for your breed, as an optional add on order in combination with the Optimal Selection™ / MyDogDNA® test. This service is a partnership with Optigen laboratories that will be particularly useful for your breed, and attempts to provide as many breed-relevant DNA test results with one analysis.
Von WIllebrand’s type 2.
We did recently try to compile the newest information on vWD type II in a blog text, which you can find here:
In essence, a new study by Vos-Looshuis et al. has shown that the originally published vWD type II mutation is likely not the causal one after all. This mutation is the one the tested dog is “genetically affected” for. With the help of your hard efforts we have been trying to investigate whether Norwegian Elkhounds “genetically affected” for the originally published mutation show any signs of a bleeding disorder. As the tested dog’s clinical blood test values were within the normal range and she has never experienced any signs of a disorder, I currently find it unlikely that the mutation we and others have tested for plays a role in the development of vWD type II in the Norwegian Elkhound. With your help, we essentially reached the same conclusion for the Norwegian Elkhound as Vos-Loshuis et al. for Chinese Crested Dogs.
That is why vWD type II is no longer shown in the MyDogDNA test results, though rest assured that all results for the originally published vWD type II mutation are nevertheless stored in the background. If we see another Norwegian Elkhound “genetically affected” for what is likely a falsely published vWD type II mutation, we will still be able to reach out for further clinical tests. However, based on current science, the most responsible thing to do is not to show the vWD type II results to breeders and have them make breeding selections based on information inaccurate for the breed.