NCL (Neuronal Ceroid Lipofuscinosis) in field goldens

[red devil]

In the last couple of months a disturbing condition has received some noteriety among golden breeders. Know as Neuronal Ceroid Lipofuscinosis (NCL) it is devasting to affected dogs. I am posting a plea I made on a facebook breed group to have your field golden tested and the results posted on K9data. If enough dogs are tested this becomes just one more hoop a responsible breeder will need to jump through before breeding. Left unchecked It has the potential to become far more widespread and as such less manageable. Some big name field dogs have already been identified as carriers. While it appears the incedence of affected dogs is quite low indicating a paucity of carriers (affected dogs almost always die before their 2nd birthday) lets keep it that way thru' intelligent breeding and testing.

"For those not yet aware, a new (potentially serious) genetic condition is being investigated. Although it is particularly concerning to the owners and breeders of US field dogs, it has been identified in a N. American show dog and in a russian bench dog. This condition is present in other breeds, but only recently become apparent in goldens. The condition is known as Neuronal Ceroid Lipofucinosis or NCL. It is nasty. Affected dogs begin to show clinical signs around 18 mos and by 2 their quality of life is such that they ust be put down. Clinical signs are loss of sight, confusion followed by loss of motor skills and eventual paralysis.

Fortunately it is a recessive gene and dogs are characterised as clear, carriers or affected. Breeding a carrier to a clear will NEVER result in an affected dog, but carrier to carrier could result in affected pups and potential heartbreak. As such, I believe it is exremely important for a large portion of the field golden population to be tested, much in the way we have been testing for ichthyosis. This is potentially far more devastating than a skin disorder. Even if you do not plan to breed your dog, it is still important to test as your dog's test can potentially identify carriers among your dog's progenitors and give researchers a larger sample pool to work with.

Even as a rare condition, there are a few very well know dogs who have been identified as carriers. There is no reason whatsoever to avoid these dogs as part of a breeding program. Avoiding these dogs and other carriers would further tighten our already too tight gene pool. Intelligent decisions can be made with a simple test of the sire or dam.

In the US, although Paw Print and Optigen are working to license the test, only the University of Missouri, Columbia has a test for the golden variant (CL5). The test costs $65 for a dog not displaying clinical signs. If you have the test done, please, please, please add your results to k9data.com (user managed web site for golden pedigrees) A searchable field has been added for the NCL variant.

If you cannot find the paperwork, pm an email address and I will forward it to you.

Thanks in advance... feel free to share to other sites. By education and testing we can get in front of this evil before it becomes widespread."

[Nicole DeBernardi]

In the last couple of months a disturbing condition has received some noteriety among golden breeders. Know as Neuronal Ceroid Lipofuscinosis (NCL) it is devasting to affected dogs. I am posting a plea I made on a facebook breed group to have your field golden tested and the results posted on K9data. If enough dogs are tested this becomes just one more hoop a responsible breeder will need to jump through before breeding. Left unchecked It has the potential to become far more widespread and as such less manageable. Some big name field dogs have already been identified as carriers. While it appears the incedence of affected dogs is quite low indicating a paucity of carriers (affected dogs almost always die before their 2nd birthday) lets keep it that way thru' intelligent breeding and testing.

"For those not yet aware, a new (potentially serious) genetic condition is being investigated. Although it is particularly concerning to the owners and breeders of US field dogs, it has been identified in a N. American show dog and in a russian bench dog. This condition is present in other breeds, but only recently become apparent in goldens. The condition is known as Neuronal Ceroid Lipofucinosis or NCL. It is nasty. Affected dogs begin to show clinical signs around 18 mos and by 2 their quality of life is such that they ust be put down. Clinical signs are loss of sight, confusion followed by loss of motor skills and eventual paralysis.

Fortunately it is a recessive gene and dogs are characterised as clear, carriers or affected. Breeding a carrier to a clear will NEVER result in an affected dog, but carrier to carrier could result in affected pups and potential heartbreak. As such, I believe it is exremely important for a large portion of the field golden population to be tested, much in the way we have been testing for ichthyosis. This is potentially far more devastating than a skin disorder. Even if you do not plan to breed your dog, it is still important to test as your dog's test can potentially identify carriers among your dog's progenitors and give researchers a larger sample pool to work with.

Even as a rare condition, there are a few very well know dogs who have been identified as carriers. There is no reason whatsoever to avoid these dogs as part of a breeding program. Avoiding these dogs and other carriers would further tighten our already too tight gene pool. Intelligent decisions can be made with a simple test of the sire or dam.

In the US, although Paw Print and Optigen are working to license the test, only the University of Missouri, Columbia has a test for the golden variant (CL5). The test costs $65 for a dog not displaying clinical signs. If you have the test done, please, please, please add your results to k9data.com (user managed web site for golden pedigrees) A searchable field has been added for the NCL variant.

If you cannot find the paperwork, pm an email address and I will forward it to you.

Thanks in advance... feel free to share to other sites. By education and testing we can get in front of this evil before it becomes widespread."

It is great you are raising awareness of this condition, but this post is not accurate. Embark is also correctly testing for this condition (not just U of Mo).

[drunkenpoacher]

Never heard of it, thanks for posting. My boy is getting hips, eyes, etc next month.
I'll PM you for the paperwork.

[Judy Myers]

You can order this test from OFA for $65. They send you a cheek swab and the paperwork to collect and send the DNA.

[red devil]

More carriers and affected dogs being found.....this really is nasty. If you have a field golden HAVE HIM/HER TESTED PLEASE.

[kcgold]

IMPORTANT COMMUNICATION FROM the Golden Retriever Club Of America HEALTH & GENETICS COMMITTEE.
We have received several recent communications from owners of Golden Retrievers related to Golden Retrievers diagnosed with neuronal ceroid lipofuscinosis (NCL). Here is what we know today:
A peer-reviewed 2015 publication indicates that NCL is a rare but fatal recessive inherited disease of Golden Retrievers. A genetic test is available that can identify affected, carrier, and normal individuals. In Golden Retrievers the disease is due to a mutation in CLN5 that is only found in Golden Retrievers. Carriers are believed to be healthy but to prevent disease in their puppies, should only be bred to a dog that has normal CLN5. The peer-reviewed publication is available online at https://www.sciencedirect.com/…/artic…/pii/S109671921500089X
The NCLs are neurologic diseases caused by the accumulation of material (ceroid and/or lipofuscin) in a part of the cell known as the lysosome, that would normally serve to digest that material. Material accumulating in the lysosomes causes a large group of diseases known as the lysosomal storage diseases. Thus, the NCLs are one of many inherited lysosomal storage diseases. There are many different types of NCLs that affect many different species. In the 2015 publication, Golden Retrievers affected with NCL were homozygous for a previously undescribed mutation in CLN5, a gene known to cause NCL when mutated in humans or border collies.
Golden Retrievers who are affected with NCL were apparently normal when young and began to display signs of neurologic disease at about 15 months of age. The signs are progressive and include: pacing and circling, anxiety, aggression, vision problems, trembling and seizures.
In the 2015 publication, the CLN5 mutation in the affected Golden Retrievers was investigated in 18 related Golden Retrievers from that Golden family. The researchers also investigated whether that mutation was present in randomly selected DNA from Golden Retrievers in the CHIC DNA database (532 samples) or in archival samples at the University of Missouri (530 samples). The researchers also looked for that mutation using archived DNA from 143 dogs of 99 other breeds. In the clinically affected dogs, the researchers identified a deletion of 2 DNA bases in exon 4 of CLN5 that shifted the reading frame of the CLN5 DNA so that an abnormal protein would result (DNA is transcribed into RNA and RNA is translated into protein so inherited diseases are generally due to an abnormal protein). In the original Golden Retriever family with clinically affected members, all 3 of the affected Goldens were homozygous for the mutation (had 2 copies of the CLN5 mutation) and 11 of the family members were carriers. All carriers were clinically normal suggesting that this is a recessive disease.
In the 1062 randomly selected DNA samples from Golden retrievers, 8 had a single copy of the gene and 1 was homozygous. The owners of the 1 homozygous individual were contacted and that dog had been euthanized with clinical disease consistent with Golden Retriever NCL. The earliest DNA sample was from 1994 so the disease appears to have been in our Golden DNA pool for quite some time. However, the carrier rate for the CLN5 mutation from the random sample in Golden Retrievers was 8 of 1062 or 0.75% at the time those samples were taken. Therefore, CLN5 is believed to be rare in the general population of Golden Retrievers.
The mutation that causes Golden Retriever NCL was not found in 143 dogs of 99 other breeds. Thus, the test developed for CLN5 in the Border Collie would NOT be expected to identify the CLN5 mutation in Golden Retrievers. It is also important to remember that the quality of DNA laboratories varies – something that was the topic of a recent commentary in the leading scientific journal Nature https://www.nature.com/articles/d41586-018-05771-0 The issues associated with DNA testing include laboratory quality control, validation, and appropriate interpretation. These are the reason for the Dog WellNet’s Harmonization of the DNA testing in Dogs activities. The online link to that activity is at https://dogwellnet.com/ctp/ .
Thus, at this time, we know: 1) the University of Missouri developed a test for CLN5 in Golden Retrievers that correlated with clinically affected dogs and carriers, 2) the basis for that test is published in the peer-reviewed scientific literature, and 3) CLN5 was rare in Golden Retrievers at the time of the one peer-reviewed publication (2015). Based upon personal communication, we believe that Embark and Optigen will be able to test for the CLN5 mutation in Golden Retrievers. These tests can be performed on DNA harvested from blood samples. OFA can now perform the test for CLN5 mutations in Golden Retrievers using cheek swab samples.
The development of a test for CLN5 mutations in Golden Retrievers is important because CLN5 carriers may be rare in the random samples of DNA in CHIC but it will likely be common in Goldens related to affected and carrier Goldens. Remember that 11 of the 18 Goldens in that original family were carriers.
Here is the take-home message:
WARNING: the test developed for CLN5 in the Border Collie would NOT be expected to identify the CLN5 mutation in Golden Retrievers.
GOOD News: A test specific for the CLN5 mutation of Golden Retrievers IS available. The GRCA Health and Genetics Committee recommends that prior to breeding, close relatives of CLN5 affected and carrier Goldens get tested for CLN5. To date, all Golden Retrievers known to be affected by the CLN5 mutation have had symptoms before 2 years of age and subsequently died. Therefore, CLN5 carriers should only be bred to Goldens tested as CLN5 normal/clear.
We know of two groups currently advertising DNA tests for the Golden Retriever CLN5 mutation but additional companies are likely to offer the test soon. Here is the information on those tests.
1) University of Missouri/Orthopedic Foundation for Animals https://www.ofa.org/…/dna-te…/neuronal-ceroid-lipofuscinosis
2) Embark https://embarkvet.com/health-list/

[1gunner]

FYI a Facebook page has been created to discuss address the issue.

https://www.facebook.com/groups/NCLGoldens/?__tn__=HH-R

[RunningReds]

Also this is not just in field lines. And it has been found in European bred dogs. At this time there appears to be no common denominator. Please test all your goldens, no matter the breeding.

[Judy Myers]

K9data has a new search field listing dogs that are Affected, Carriers, and Clear. Go to the search for dogs page. At the bottom, you will see an NCL Genetic Status field with an arrow. Click the arrow and you can then click on Affected, Carrier, or Clear and then on Submit to see a list of those dogs that have been tested and reported for each category. There aren’t many listed yet - about 30 carriers and 9 affected. But the test is new and many people have just sent in their tests. The numbers will likely grow as those test results come in. If you find you have a dog related to a carrier, it is especially important for you to test if you are planning on breeding it. But for research purposes, it’s important that as many dogs as possible be tested. Please test your dogs.

[1gunner]

I wanted to revisit this thread now that more and more dogs have been tested. Luckily, only 9 have tested as "affected". Ther're are however, quite a few that have tested as carriers. And in many cases we're talking about some really nice dogs. What would the breeding protocol be for carriers in the future. Obviously, you dont want to breed carrier to carrier. But would you ever knowling pair a carrier to a clear knowing that you will get some carrier offspring? Much like with you do with ichthyosis. Or do you completely avoid breeding all known carriers altogether in hopes of eradicating NCL?