PRA LATEST UPDATE

Progress to Find the Genetic Mutation Causing PRA in Miniature Lon-Haired Dachshunds

Exciting Progress

The Animal Health Trust has made very significant progress during 2004 towards the identification of the genetic mutation that causes Progressive Rentinal Atrophy (PRA) in Miniature Long-Haired Dachshunds (MLHDs).  Having Narrowed the location of the faulty gene to a single dog chromosome over the last few years, during 2004 we have narrowed the search even further, and have, possibly identified the mutation that causes PRA.  The DNA mutation is within a gene that is shared between humans and dogs, and in humans mutations in the same gene has been shown to cause a very similar disease to PRA.  If we have in fact identified the causative PRA mutation we will be able to develop a test to enable breeders to distinguish between clear, carrier and affected dogs.

Confirmation

Before a diagnostic test can be offered the AHT needs to be absolutely certain that the mutation we have discovered is what is truly causing PRA, and is not just a unusual region of DNA that is close to a different mutation (as yet undiscovered) that is the real cause of PRA.  To do this we are testing DNA from known PRA cases, and from known PRA carriers, to make sure that all the affected dogs have two copies of the mutation, and all the known carriers have a single copy.  To expedite this validation process we are requesting as many samples as possible from known cases and known carriers; the numbers of these samples we receive will determine the speed with which we can confirm our findings.  These samples can be submitted to the AHT in complete confidence, anonymously if desired, and we will test the samples free of charge until the end of 2004.  We will inform the owners in writing of the results, although the test is currently unofficial and certificate will be issued.  At this time we are only requesting samples from dogs whose PRA status is known.

Diagnostic Test

The possibility remains that the mutation we have identified in not the cause of PRA, in which case we will need to start work to discover the real mutation.  Currently, however, we are confident we have identified the true mutation and of the validation procedure described above progresses well we hope to be able to launch an official diagnostic test early next year.

A Word of Thanks

This work owes much to the many many dachshund owners who have donated samples from their dogs, often at their own expense, over the years and we would like to say a big thank you to everybody who has contributed to this effort.

Thank You.