PPC (Posterior Polar Cataracts)
All NyaStar Irish Red and White Setters are Tested per CERF guidelines.
We ask that if you own an IRWS over 8 years of age, please have the eyes tested & send a cheek swab sample to the Animal Health Trust to work on the genetic test.
It was discovered in 1995, when a father & son were found to have the cataract in a routine eye examination.
Then a little later a mother and daughter were found to have PPC too. This caused us - Genetic Sub-Committee to consider it to be hereditary and began to keep records.
The cataract is an upside down-Y shaped area of opacity on the rear surface of the lens - hence Posterior Polar Cataract.
The dogs are not blind and the cataract can appear at any time - the oldest dog to suddenly present with the catacts was 8 years old, after being examined every year up to then. - So 'variable age of onset'.
The problem is, if it is hereditary and appears later in life, affected dogs could have produced litters with affecteds before their cataracts could be seen.
The only thing we could do at that time was to advise and insist that dogs should be apparently clear before being bred. Although there have only been 16 affected dogs, breeders are wary of breeding and the only way to know for sure whether a dog has the PPC gene is to have a DNA test.
In 2006 we raised £3000 and were given a Grant of £26,000 by the KC Charitable Trust to fund the research and get a DNA Test.
The work was undertaken by Professor Matthew Binns at the Royal Veterinary College, London, he had over 100 blood samples that included affected dogs and apparently clear dogs. There was a hitch in 2007 when the SNP chip (used to sequence the DNA) was unable to be manufactured - this affected all gene research not just ours. But by the end of 2007 the SNP chip was purchased and we were assured that it would not take long. However as you have seen Professor Binns has been unattainable since December 2007 and after a whole year of trying every whichway to contact him, the PPC Project has been transferred to the Animal Health Trust who are now working on it.
There has been some concern that it is not a dominant gene, could be recessive, could have modifiers. finding the gene is like finding a needle in a haystack and we do not have enough affected dogs to provide samples..... it was never going to be an easy task nor a quick one at the best of times.
Fortunately the condition does not cause the dogs any inconvenience, its only concerning thing is that a secondary cataract can develop which does render the dog blind.... we have only two cases of this over the 30 years of IRWS.