PRA (progressive retinal atrophy) test

Jossan and Albert are tested negative for PRA.

That is great news, it means that the kittens any of them parents will never get PRA and become blind, no matter whether the other parent is a carrier or not (this is an autosomal recessive condition). The disease is not associated with gender. Since it is a recessive disease – two copies of the gene, in this case – CEP290  mutation are required for the cats to lose their vision. There is no treatment available for the condition.

PRA stands for Progressive Retinal Atrophy. 

The cats with two copies of the CEP290 mutation have normal vision at birth.  Vision loss progresses slowly and is variable, with most cats becoming blind by usually 3-5 years of age.  Some estimates are that 33% of Siamese and related breeds are carriers of the mutation, meaning that about 11% of them will eventually become blind later in life.

You can check which cats are tested so far and what the results are here for female cats and here for male cats. Click on [h] far right next to the cat’s name to see the test results.

Please observe: not everyone has tested their cats used in breeding programs yet. I have become aware of this just a few months ago, after a study in Finland has been done. Also, not everyone is going to register the results in Pawpeds; not all the breeders are aware of the existence of the Pawpeds – the cat database. But more and more reports will arrive with time. If you plan to mate your Siamese/Balinese/Oriental or buy a kitten from a breeder, make sure you know the PRA status of the cat in question. Carriers and PRA-negative cats will never develop PRA. Only homozygous cats will.

The goal is that with selective breeding where a carrier can be mated only with a non-carrier we will be able to minimize the appearance of the mutation within the Siamese gene pool.

We sent our cats’ DNA to Veterinary Genetics Laboratory, UC Davis, California. We got the results 8 days after the lab had received my letter with the samples. Read more about PRA here.

Information in Swedish:



Från rekommendationer:

“Alla köpare av kattungar som är bärare och kattungar vars PRA-status är okänd (där inte båda föräldrarna är fritestade och negativa) ska informeras om sjukdomen, om det faktum att en förälder är bärare och om den risk som finns om kattungen används i avel.

Heterozygota bärare kommer visserligen aldrig att få några symptom och då kan man lätt tänka att informationen är irrelevant för den som köper en kattunge bara till sällskap.

Men eftersom det inte alls är ovanligt att köpare av katter till sällskap senare ändrar sig och i alla fall vill ta en kull efter sin katt och de då kanske drar igång det hela utan att höra med uppfödaren till katten, så är det lika viktigt att köpare av kattungar till sällskap också till fullo förstår vad sjukdomen innebär och vad det kan betyda för deras kattunge.”

P.S. Goofy, dad to A-litter and dad to the upcoming litter will also be tested for PRA in the near future. Judging from Albert’s results, he is negative or in the worst case, a carrier, but cannot be a homozygote.

Updated, May 2011: Goofy is also tested PRA-negative. All the kittens that he and Jossan had are PRA-negative since both parents are not carriers.

2 comments on “PRA (progressive retinal atrophy) test

  1. Pingback: Maskefarge, PRA og DNA testing « April in Paris "Arwen" NO*Aceso´s blogg

  2. Pingback: Progressive Retinal Atrophy - Siamese Cats and Kittens

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