New mutations : an ethical question

[sandgrubber]

I've been trying to understand the additional genetic testing suggestions and requirements for Labradors.  CNM (centronuclear myopathy) is especially interesting.  The geneticists find a lot of carriers (between 10 and 25% depending on what country).  They also conclude that it's a new disease that probably arose from a single mutation, and that it's dissemination is mostly due to a 'very famous' UK stud dog ~50 years (17.5 generations) ago. 

 

I can understand why the dog in question isn't named.  But it's annoying as hell that instead of concentrating efforts on pedigrees that descend from the stud in question, CNM testing is on the way to being required / recommended by LR Clubs around the world.  I'm also bothered that I'm not seeing this mutation discussed in conversations about line breeding and popular sire syndrome. 

 

Warning : the article is highly technical. 

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3465307/#!po=2.02703

Edited July 4, 2020 by sandgrubber
Expanded acronym

[JRG]

Fascinating.  Thank you for posting.

[Diva]

Interesting that they suggest the sire in question came from a marginal line, or the introduction of genetic diversity from other breeds. 

[DogsAndTheMob]

I disagree. I have painful memories of sifting through pedigrees for a relative, looking for potential Border Collie stud dogs that didn’t descend from the first known carrier of ceroid lipofuscinosis. Almost every dog was descended from that dog within 4 generations. The best we could find was 4 generations descended from a half-sibling of the “source dog”. It was later suggested that another unrelated, and very popular, stud dog had also been a carrier. I can’t imagine trying to sift through half a century of pedigrees or even trusting that there were no pedigree mistakes within many generations with so many different breeders producing puppies. 

DNA testing provides a much simpler tool for identifying, and potentially eliminating, genetic diseases. If I was buying a Labrador puppy and was concerned about CNM, I would be looking for a puppy from DNA tested parentage.

[sandgrubber]

5 hours ago, DogsAndTheMob said:

I disagree. I have painful memories of sifting through pedigrees for a relative, looking for potential Border Collie stud dogs that didn’t descend from the first known carrier of ceroid lipofuscinosis. Almost every dog was descended from that dog within 4 generations. The best we could find was 4 generations descended from a half-sibling of the “source dog”. It was later suggested that another unrelated, and very popular, stud dog had also been a carrier. I can’t imagine trying to sift through half a century of pedigrees or even trusting that there were no pedigree mistakes within many generations with so many different breeders producing puppies. 

DNA testing provides a much simpler tool for identifying, and potentially eliminating, genetic diseases. If I was buying a Labrador puppy and was concerned about CNM, I would be looking for a puppy from DNA tested parentage.

If the kennel clubs maintained pedigrees digitally, and linked internationally, it would be quick and easy.  

[Diva]

No decent online breed archive for Labs? We have one (well several, but one main one in English) and it is well supported, a large % of the breed are on it back to founders and the collective oversight keeps the error rate acceptably low.

But for a quality of life affecting disease I would still test- the chance of a wrongly registered pedigree is low but I wouldn’t take the chance. Over 50 years there are a lot of chances for a sire not quite being who was recorded.