PSSM carriers and genetic testing

[pheobs]

So there appears to be some drama as to a researcher who has been releasing lists of Connemara stallions that are carriers for PSSM, as evidenced by results of genetic testing. Apparently this is causing some knee jerk reactions in potential breeders who are blacklisting certain lines due due to not wanting to breed to a carrier stallion.

The argument I heard was that releasing this information is causing undue panic, and that removing all carrier stallions from the breeding pool would result in the death of the breed? Apparently Connemaras are considered a “rare” breed?

Would love to hear opinions/elaboration on this situation . I haven’t heard anything about it but I dearly love the Connemara as a breed and would absolutely hate to hear that they are declining, but I also understand the importance of removing harmful genetics from
the breeding pool. I also was not aware that the breed was in danger of dying out, as I thought it was actually becoming increasingly popular!

[Ghazzu]

I’d be a bit surprised the information is being divulged by a “researcher”, as releasing such information without permission of the owner might be a breach of institutional ethics.

[bugsynskeeter]

Does this “researcher’s” name begin with a P?

[pheobs]

No clue! All I know about it is what I posted. That’s why I was hoping to get some more information. I’d like to know where I can find this “research” or even really just learn what it is.

[bugsynskeeter]

Depends on who is doing the research on whether it is available or not. If it is who I think it is, there isn’t anything published.

[vineyridge]

Connemara genetic defects are not news. The ponies are, if not yet, very close to rare breed status. Several years ago, the breed was faced with a genetic hoof defect. A policy was devised to deal with the problem, and, AFAIK, it is working.

But what is acceptable for breeding within a rare breed may not be acceptable for breeders of outside crosses.

[JB]

I would think it’s illegal for a research to divulge names of stallions without explicit consent from the owners. I would probably be looking into that and not being afraid to set up a lawsuit.

This seems to be falling into the same scenario as Fragile Foal Syndrome, where many people immediately proclaimed all carriers should be removed from the gene pool. I realize this is different - FFS carriers are (likely) not affected at all, while we know that PSSM is a problem even in the heterozygous state.

That said, I agree that if this can be handled the same as the hoof wall separation disease, it should be. Putting effort into working around the problem in a constructive way is much better for the breed than just throwing the baby out with the bathwater.

[Ghazzu]

I’ve been looking around to try and find anything published in the literature wrt PSSM in Connemaras, and just found this, from 2010–“The GYS1 mutation was not detected in the Thoroughbred, Akhal”Teke, Connemara, Clydesdale, Norwegian Fjord, Welsh Pony, Icelandic, Schleswig Coldblood and Hannoverian”
This was a population of horses sampled for a study on estimated prevalence, so not exhaustive, but would indicate a relatively low prevalence in the breed.

[Ghazzu]

In a related study in the UK, 2 Connemara crosses (1 Welsh x and one TB x) were heterozygous for the mutation.
This study was looking only at horses which had a diagnosis of rhabdomyolysis.

[Ghazzu]

Given the dearth of evidence from scholarly sources that there is a significant incidence of the GYS1 mutation in Connemaras, I have to wonder whether the flap might not be related to the HWSD and the OP’s source was confused about it.

[Janet]

That (HWSD) would be my guess too.