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Discussion Starter #1
I think this preview that RJ sent out today is going to be a powerful tool in educating the general buying public about the disorder.

http://www.retrieverjournal.com/passblast/parjmar09.html

After you read it, I have a request out of curiosity. I'd like to know how many of you would have asked about EIC testing on parents of prospective litters BEFORE you read this, and how many are going to ask about it now?

Anne
 

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We had never her of this disorder before our last lab. She started to exhibit symptoms around 1 1/2 years of age. It was always random and more prevalent in the hot weather. My husband scoured the internet looking for answers and finally found info on this and presented it to our old vet. He knew very little about it as well. When we mention it to people now (including vets and breeders) they look at us like we are from outer space making an excuse for our dog's "lack of stamina".

Glad this is getting some attention.
 

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I just got on a list for a puppy a few weeks ago - we asked about EIC. Thanks for sharing the article, glad someone is getting the word out :)
 

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Before I found this forum (as a labrador layperson, if you will) I knew to ask about hips, maybe elbows, but elbows weren't as "important" as hips. :rolleyes:

Now, I will/would ask about EIC, heart, eyes, CNM, as well as others (allergies, GI issues, seizures etc). Because of this article and other postings (mostly by you Anne, regarding EIC/CNM! ;))
 

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Discussion Starter #5
Before I found this forum (as a labrador layperson, if you will) I knew to ask about hips, maybe elbows, but elbows weren't as "important" as hips. :rolleyes:

Now, I will/would ask about EIC, heart, eyes, CNM, as well as others (allergies, GI issues, seizures etc). Because of this article and other postings (mostly by you Anne, regarding EIC/CNM! ;))

Great! Just for the record though... I honestly think sound elbows are MORE important to have than hips due to more weight being born on the dogs front (at least 60%). Many dogs can live without much issue w/ HD but many elbow issues are often very debilitating. Anne
 

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I'd heard of hips, eyes, seizures, but EIC was unknown when I got Puff (2001). Having seen an AKC Lab suffer with it, it'd now be one of the things I'd want tested.


 

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Great! Just for the record though... I honestly think sound elbows are MORE important to have than hips due to more weight being born on the dogs front (at least 60%). Many dogs can live without much issue w/ HD but many elbow issues are often very debilitating. Anne
I agree, the idea that hips were more important was an old one, my view has most definitely changed since then! :)
 

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It's important to remember that there are many uncommon heritable conditions that can occur in Labradors and any breed of dog for that matter. I personally know literally hundreds of show bred Labradors very well in the last 12 years and I don't know anyone who has one with EIC. I'm not saying that it isn't out there but it's very uncommon.

It's also important to know that the gene that this company found is "highly associated" with EIC and having two copies does not mean the dog is affected and so it DOES NOT ACTUALLY CAUSE THE CONDITION. In fact only 70% of the dogs they have tested that have both copies of the gene with their skewed participants (naturally people with affected dogs sent in blood first and with more prevalence than those that have never even heard of this) are actually affected. So 30% of those that the company is saying should be affected are not and many of these are older very active dogs (competing in hunt tests, etc).

I'm not saying that a perspective puppy buyer should not be informed and it's important to ask a lot about health and soundness however making sure a breeder is testing for EIC then should go along with x-raying hips, elbows, shoulders, hocks, and wrists, testing for hypothyroidism hyperthyroidism, allergies, Von Willabrand's Syndrome, etc. I personally like to know that several generations and laterally are healthy and sound.
 

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Discussion Starter #9 (Edited)
Perhaps I should ask one of the U of MN researchers to comment on the above... seems that some folks still don't understand the language used in the "community". IOW... they (U of MN) are confident they have the gene. I've not yet SEEN PRA personally either, but know of several folks w/ dogs that have it, for whatever that is worth (and I own Carriers that are only bred to Clears).

Tell ya what, you do what you feel comfy with, and I'll do what I'm comfy with. ;) I need to be able to sleep well at night w/ my decisions.

In the end, remember you are on a public forum and... well, buyers beware.

PS, here is the link to the EIC page for others to read for themselves. The above poster is apparently so misinformed I just don't personally know where to start: http://www.vdl.umn.edu/vdl/ourservices/canineneuromuscular/faq/home.html
 

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Some Info

EIC is a gene mutation test.

We are testing for a single DNA base pair change in a specific gene, the DNM1 gene; therefore this can be referred to as a gene mutation test. This situation is different from other types of genetic tests that describe only the identification of a DNA marker that could be very far away from the EIC gene, and not be as highly predictive of the true gene and mutation as desired. The results for this EIC mutation test will always be the same for samples provided from the same dog.


Why say "highly associated" and not causes:

Scientists are always cautious in reporting conclusions regarding data to other scientists and to the public, and in so doing usually try not to state anything has a 100% certainty of being correct. However, the chances that the DNM1 mutation is not associated with EIC are less than 1 in a trillion as reported in our Nature Genetics article. Nature Genetics is one of the most respected and prestigious scientific journals.

The role of DNM1 in nerve and muscle function clearly supports it being an extremely plausible EIC gene. A description of the precise effect of the DNM1 mutation on the function of the dynamin 1 protein remains before we can even more confidently state that the DNM1 mutation (i.e., E form of the this gene) is the causative EIC mutation.


Being a carrier of the EIC mutation is very common in field and bench line Labradors. We have tested more than 6,000 Labradors and the carrier rate in our sample population (which is not random, but is large) is >30%. It is estimated that 3-5% of the population is EIC affected. Any disease with a greater than 1% affected frequency in the population is considered to be a major health issue within the breed.

Lastly, greater than 80% of genetically affected dogs have experienced episodes of collapse by three years of age. Others may not show signs of collapse until later in life. Confirmed first collapse has occurred in dogs as old as age 10yrs. However, even genetically affected dogs that never show signs of collapse do frequently produce collapsing affected offspring. So, while not every dog with the affected genotype will collapse, all dogs with EIC are homozygous for the DNM1 mutation. This is referred to as incomplete penetrance. The variation in the severity of symptoms is referred to as expressivity.

Opitgen also discuss these terms in their glossary:
Expressivity - Some diseases are very predictable in terms of age of onset and severity of symptoms. Such a disease is typically “expressed” in the same way in each affected individual. But some conditions, for example Toller PRA, don’t fit this description. They might have very different ages of onset, different degrees of severity, and/or different rates of progression even within the same line, the same pedigree, or even the same litter. One confusing result of reduced or variable expressivity is that a dog can be affected according to a DNA test, yet show no clinical signs of disease until much later, or show only mild and slowly progressing clinical signs of the disease. This dog must not be confused with a case of false positive.

Penetrance - The extreme case of reduced expressivity is incomplete penetrance. An inherited disease has incomplete penetrance in cases where the individual is known to have the affected genotype, but never shows the clinical disease. Even so, the clinical disease shows up again in its offspring. Clearly, the affected genes were present in the parent but the disease didn’t “penetrate” to a recognizable state. Again, this case must not be confused with a case of false positive. Incomplete penetrance has been documented in some PRA-affected Toller pedigrees.

I hope this helps.
 

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Discussion Starter #11
Thanks Katie! :) For those who aren't aware, Katie is one of the U of MN scientists involved w/ the EIC research and test development. Anne
 

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windycanyon - I am a geneticist by trade having an M.S. in molecular biology and spent five years as a research associate at a gene therapy company prior to staying home with my children. I have my name on six published journal articles. I am not misinformed. I merely stated my opinion and others can use as they wish. You can test or not test - I don't care. What I do care about is that people have both sides to digest.

However, the chances that the DNM1 mutation is not associated with EIC are less than 1 in a trillion as reported in our Nature Genetics article. Nature Genetics is one of the most respected and prestigious scientific journals.
But what are the chances that this particular gene does not work alone? In other words can other genes be needed for EIC to be present? In my opinion yes absolutely.

Being a carrier of the EIC mutation is very common in field and bench line Labradors. We have tested more than 6,000 Labradors and the carrier rate in our sample population (which is not random, but is large) is >30%.
6,000 dogs is a large sample size if it's random but in this case it is not. Again the population that has been tested is absolutely skewed by those that have had a problem with EIC and thus being the ones that sent in blood in much larger numbers than those that did not. Also this sample includes BOTH field type and show type dogs. EIC has been seen in field type dogs with greater frequency than in show type. Up until this test came out it was thought to be strictly a field type condition and very very rarely affecting show type dogs - what changed?

It is estimated that 3-5% of the population is EIC affected. Any disease with a greater than 1% affected frequency in the population is considered to be a major health issue within the breed.
So 3 - 5 dogs out of 100 are affected and 30 or more dogs out of 100 are carriers. If I count 5 breeders that I know really well I will get over 100 dogs that I know very well and have worked with in the field, etc. I don't know anyone who has or produced an EIC affected dog. I'm not saying that there might be one in a pet home that we don't know about however given that up to 5 dogs out of 100 should be affected that would mean my friend who currently has about 25 dogs should have 1 in her kennel and she does not. How can this be? How can it be that none of us have ever heard of anyone producing an EIC affected dog? I have a friend who has been breeding very successful show type Labradors for over 30 years. She has about 10 litters per year and her dogs are the foundation of many many other breeders out there. She currently has about 30 dogs and keeps that many routinely. She has never to her knowledge produced an EIC dog or had one at her kennel??????

Lastly, greater than 80% of genetically affected dogs have experienced episodes of collapse by three years of age. Others may not show signs of collapse until later in life. Confirmed first collapse has occurred in dogs as old as age 10yrs.
Field type or show type or both combined?

So from my standpoint I see this as a condition that affects <1% of the population of the dogs that I breed.
 

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Discussion Starter #13
Hey Sharon,

We've had several show breeders in the NW recently report collapses by pet owners. I guess they too are wrong? I guess the person on page 1 who had the collapsing dog is wrong? And Bob PR who witnessed a collapse is wrong also?

It's amazing to me that anyone who has actually done any scientific research with a legit program would be so critical of someone elses work that they did not take part in....:mad:

Published also,
Anne
 

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I have a 4.5yr old lab from a very reputable breeder in my area that I had tested this year after knowing that is what he had but no way to confirm it.He is affected according to the results.
I called my breeder to let her know;she was taken aback to say the least.She was going to have his sire tested(his dam has since retired from breeding)but I have not heard anything from her on his test.She did promise to inform me of his results.
In the future,I will not buy from a breeder who does not screen for this,as well as all the other screenings.This has been very hard for our family;we love him to death but he is not able to be as active as we would like in our pet.:(
 

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So from my standpoint I see this as a condition that affects <1% of the population of the dogs that I breed.
I think experiences like the one posted above and others (as Anne mentioned) indicate that even one dog affected is one dog too many when it is possible to weed out and prevent this condition from occurring in the first place.
 
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