Mini Wire Lafora Screening update (16 Jan. 2012)

Post date: Jan 19, 2012 9:25:6 PM

The WHDC has issued the following update and a revised spreadsheet of test results:

Introduction:

We are really grateful to everyone for their patience over the past few months and also for the high level of commitment shown by MW owners. We will continue to provide regular updates on progress and our analysis of pedigrees, but any of the team are willing to answer questions at any time. We are happy to offer information and advice about known carrier / affected animals based on our analysis of pedigrees, to support positive breeding practices and reduce the incidence of the disease.

Results:

Despite a promise that we would have all results by 16th January, Centogene have to date not issued all of them. Everyone currently waiting for a test result will be informed of their results as soon as possible when we receive them and the database available at the WHDC website will be updated. We have had 9 new results, 8 unaffected and 1 new affected.

At present, we have test results from 173 dogs, we have identified 22 that carry two copies of the Lafora mutation and are therefore “Affected”.

Carrier Test:

Despite extensive trials, Centogene have not been able to perfect the carrier test on saliva swabs. However, the laboratory will now trial the test on blood samples and we will report back here on the success of that.

We are also currently discussing with the Canadian team the possibility of them having a certificated, reinstated blood carrier test. They are also pursuing research into a saliva carrier test.

Although it is disappointing that the carrier test has not so far been possible, the value of the affected / unaffected testing cannot be under-estimated. This information enables us to be certain that all parents and progeny of affected animals will be AT LEAST CARRIERS and if these parents and progeny are tested as unaffected there will be no further need for tests, all of these WILL be carriers.

We are continuing to compile a database of information about dogs tested as affected and those clinically diagnosed as affected, so that we can gain as wide a picture as possible. We plan to identify their parents and all progeny, so that we can build our knowledge of the carrier population, whilst waiting for a full carrier test to be up and running. As soon as it is available, we will publish details of what will be needed to complete a full carrier test.

It is still advantageous to do a saliva swab for affected / unaffected in the first instance, particularly now that we have test results and /or pedigrees for 300 dogs and especially if there is evidence of affected or carrier dogs in their background. This applies equally to both breeding stock and dogs that are not, as early diagnosis of the condition means that dietary changes can be made that may affect the severity of onset in dogs identified as affected.

For many people, given the large number of results we now have, it may not be necessary to opt for a blood-based carrier test. However, if a dog is unaffected from a saliva test and not a direct descendant of an affected dog, then the blood test will be needed (at present) to identify its carrier status.

Costs:

The test was priced at £80 for “new” dogs tested and £30 for those that had already been tested for affected / unaffected in Canada during 2010. As a result of the funding we have received and renegotiating costs with Centogene, we are able to offer the current test at the same price as the 2010 Canadian test. People can request £30 refunds or leave the funds “in the pot” for a carrier test when available, or to go towards a second saliva test.

This will be dealt with on an individual basis, so please contact the Coordinator after 31st January to discuss your preference. Please note that Nora is on holiday from 13th to 27th January.

Breeding:

In the absence of a full carrier test, the advice on breeding remains that:

It is advised NOT to use affected animals for breeding.

Through pedigree analysis, endeavour to use assumed “clear” animals on known carriers, therefore reducing the risk of producing affected animals.

Carrier to carrier matings WILL produce some affected stock (refer to the guide on this site) and therefore these matings are not desirable. However, if breeders choose to mate two known carriers, all puppies from such matings should be saliva tested so that their new owners can be told their Lafora status.

We are also working to see if we can develop a statistical model that, based on the test status of dogs and their ancestors, should calculate a predicted risk level for prospective matings.