# Lethal White Foals



## Reno Bay (Jul 8, 2012)

Actually, most of us do know this...that's what LWO is. Homozygous for frame.


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## oh vair oh (Mar 27, 2012)

Following are nine common myths regarding lethal white syndrome. The correct information is provided by the University of Minnesota Equine Genetics Group. 
*Myth #1:* All overo horses are carriers of the lethal allele. 
*Fact:* There are many overos that do not carry the lethal allele. ​ *Myth #2:* Twenty-five percent of foals from two overo parents will be lethal whites. 
*Fact:* Because there are overos that do not carry the allele, the incidence of lethal white syndrome is less than 25 percent in overo-to-overo matings. ​ *Myth #3:* Registered tobianos, Solid-colored Horses, or Paint crosses cannot carry the lethal allele. 
*Fact:* There are tobianos that have overo bloodlines, and these horses can be carriers of the lethal allele. Solid-colored Horses and Paint crosses can carry the lethal allele. ​ *Myth #4:* Totally white Paints are not carriers of the lethal allele. 
*Fact:* These white horses are often carriers of the lethal allele. ​ *Myth #5:* All totally white foals born to two overo parents are lethal whites. 
*Fact:* There are totally white Paints that are not affected by the lethal white syndrome. ​ *Myth #6:* Mares cannot produce lethal foals in consecutive years. 
*Fact:* The genetic make-up of one foal does not affect subsequent births. ​ *Myth #7:* Only one parent determines if a foal will be a lethal white. 
*Fact:* Both sire and dam contribute a copy of the lethal allele. ​ *Myth #8:* Crop-out Quarter Horses cannot carry the lethal allele. 
*Fact:* A small number of crop-outs have been tested and found to be carriers of the lethal allele. ​ *Myth #9:* You can reliably tell the carrier status of a Paint by their color pattern. 
*Fact:* This is false.​


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## Breezy2011 (Nov 23, 2012)

Yes exactly, I am just saying to everyone who says lethal white foals can be born with any horse (I have had people on here tell me that) that to have a chance of producing a LW foal, both parents have to have an overo gene.


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## Reno Bay (Jul 8, 2012)

Any horse _can_ have the frame gene, even if they have little to no white on their body. So technically every horse should get tested for frame to be safe. Obviously a homozygous recessive frame horse, oo, does not have any frame and cannot produce a LWO foal. There are heterozygous frame horses, Oo, that display only a star or no white at all and others that are obviously frame and very loudly display white. Technically, yes, _any_ horse has the potential to produce a LWO foal if they are hiding frame.


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## Chiilaa (Aug 12, 2010)

Reno Bay said:


> Any horse _can_ have the frame gene, even if they have little to no white on their body. So technically every horse should get tested for frame to be safe. Obviously a homozygous recessive frame horse, oo, does not have any frame and cannot produce a LWO foal. There are heterozygous frame horses, Oo, that display only a star or no white at all and others that are obviously frame and very loudly display white. Technically, yes, _any_ horse has the potential to produce a LWO foal if they are hiding frame.


Unless the horse is of a breed that cannot carry frame.


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## Reno Bay (Jul 8, 2012)

Chiilaa said:


> Unless the horse is of a breed that cannot carry frame.


Obviously.

Kindly note, I did say if they were hiding it ;D


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## paintedpastures (Jun 21, 2011)

Breezy2011 said:


> Yes exactly, I am just saying to everyone who says lethal white foals can be born with any horse (I have had people on here tell me that) that to have a chance of producing a LW foal, both parents have to have an overo gene.


 to start "Overo" is a blanket it includes Splash,Sabino & Frame overo. It is ONLY the Frame overo gene that in in homozygous form produces a Lethal white baby:-(. For that to happen both parents must be carriers of Frame{OLW}.When mated they have a 1 in 4 chance the baby produced will be a lethal white. The other 2 overo genes are negative for OLWS as are Tobiano's{not an overo but another patterning gene}. Problems arise as many horses can be Frame overo but it is minimally expressed or maybe present in combination with other paint patterning genes so not always recognizable phenotypically.Only sure way is to have your horse tested! see if he or she is a Frame/OLWS carrier prior to breeding,take away the guesswork & practice safe breeding by not crossing 2 carriers together:wink:


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## Lwhisperer (Sep 11, 2012)

I have a question to add, as I'm still in the learning process with all these Paint genetics:

oh vair oh, your information says that registered tobianos can also carry the Frame gene... But if they are TRUE tobianos, can they carry it? 

I'm planning to eventually breed my APHA mare and am planning to test her beforehand, as she has at least Overo and Splash, and possibly frame. However, it has always been my intention to breed to a tobiano, as I prefer a solid face to a white face and would like to increase the odds of a tobiano pattern. (I know the odds would not necessarily be in my favor, but I'd like to try. :smile: Also, I agree with those that say it is stupid to breed for ONLY color, and am more interested in a good conformation/mind. But I am also interested in color, as a side note.)

Sorry for the relative threadjack... I'm very interested to learn as much as possible about the lethal white gene!


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## Chiilaa (Aug 12, 2010)

Lwhisperer said:


> I have a question to add, as I'm still in the learning process with all these Paint genetics:
> 
> oh vair oh, your information says that registered tobianos can also carry the Frame gene... But if they are TRUE tobianos, can they carry it?
> 
> ...


Many tobianos do carry frame, yes. In breeds that carry frame, it should be the very first thing that one does - eliminate the possibility of a lethal white foal. The prospective dam should be tested, so that the breeder can then determine which stallions to pick. The breeder should also request to see a copy of the test, not just rely on the stallion owner's word - this is the only way to be 100% sure.

This guy has been tested and is homozygous for tobiano. He also has frame, again, confirmed via testing.


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## stevenson (Sep 12, 2011)

so you are saying any horse can carry it ? I have never heard of a quarter horse having lethal whites. I have not heard of this in Appys either. 
Not in Morgans , etc. I do believe that this is a Paint / Pinto genetic disorder, even though many Paints were started from quarter horses with excessive white, the Paint has breed has changed since it orgin.


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## Chiilaa (Aug 12, 2010)

stevenson said:


> so you are saying any horse can carry it ? I have never heard of a quarter horse having lethal whites. I have not heard of this in Appys either.
> Not in Morgans , etc. I do believe that this is a Paint / Pinto genetic disorder, even though many Paints were started from quarter horses with excessive white, the Paint has breed has changed since it orgin.


It is definitely NOT a "Paint/pinto" disorder. It is in MANY breeds of horse.

It is in the following breeds based on positive tests of horses of these breeds:
American Paint Horse
American Quarter Horse
American Indian Horse
American Shetland Pony
Miniature Horse
Mustang
Nokota
Spanish Mustang
Spotted Kentucky Mountain Saddle Horse
Spotted Saddle horse
Tennessee Walking Horse
Thoroughbred


Based on phenotype (what the horse looks like) it is thought to be in these breeds further:
American Saddlebred
American Warmblood
Australian Draught Horse
Australian Stock Horse
Azteca
Campolina
Criollo
Curly
Falabella
Gelderland
Missouri Fox Trotter
Morgan
National Show Horse
Quarter pony


Both these lists have been taken from this article, a great read for anyone interested in lethal white at all, and a MUST READ for a breeder Lethal White Overo: What you should know | Color Genetics

Interestingly, a member on another forum has an Appaloosa who has tested positive. So I wouldn't discount that breed from the list either.


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## Captain Evil (Apr 18, 2012)

Just when you think you have it all figured out, people come and confuse you with facts. :?


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## New_image (Oct 27, 2007)

What is the reason that a lethal white foal dies?

I knew all of this, but I guess I've never looked into that question


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## CLaPorte432 (Jan 3, 2012)

Their digestive tract is not completely formed (cannot poop) and they die usually within 24 hours. :-(
_Posted via Mobile Device_


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## NdAppy (Apr 8, 2009)

72 hours CLaporte. Sooner if put down. Otherwise they die in horrible pain from colic like symptoms due to an unformed or incomplete digestive track.


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## CLaPorte432 (Jan 3, 2012)

^^^ thank you.
_Posted via Mobile Device_


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## NBEventer (Sep 15, 2012)

I know this might sound like a dumb question but I want to confirm my thoughts on this.

I have a bay belgian warmblood mare with a white sock and blaze, I am breeding her to a CSH Stallion who is a solid bay with no white. There is no chance of frame there is there?


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## Peppy Barrel Racing (Aug 16, 2011)

Ok breezy you did not understand what was told to you the first time we talked to you about lethal white. I told you as well as others that its very likely your blue eyed mare carries frame/splash or both( These are the blue eyed causing genes). And that down the road IF you ever breed her you need to:
1. have her tested for frame
2. Make sure if she is positive for frame (very likely I think in your horses case) which would make her heterozygous or carries one copy of the frame gene. That means to be a responsible breeder you must breed to a non frame carrying stud because if the colt inherits two copies of the frame gene AKA homozygous for frame you get the 100% death with a lethal white foal.

Not sure how much genetics you've learned in school yet, but I'll try to teach you the best I can over the forum lol. When or if you learn genetics you'll probably start off with mendel pea plants and a basic punnet square. A Punnet Square can give us the mathmatical possiblities of possible genes inherited from parents and these get complicated later but were gonna go with one in its most basic form. There is more that we could probably go into even in the basic form but lets ignore that cause that will start a whole tangent of dominance and incomplete dominace and so on and I dont want to make it confusing. I'll probably confuse you anyways so sorry in advance lol. Feel free guys to correct anything I mess up, miss, or don't explain well. And it appears I can't make you a punnet square on my phone best to my knowledge so maybe someone with a computer can or you may try google to see what one looks like but basically and I'm just gonna use the allele abbreviations of N=non frame and F= frame which using the square you would get these results. NOTE: This is a simple punnet square explaining two breedings of KNOWN frame carriers not necessarily Overo/Overo because not all overo's have frame and frame is NOT only present in paints. Each parent carries the alleles of NF or heterozygous for frame and like I said I'm trying to bypass the whole dominance thing to make it simple.
Results
NN= Homozygous NO frame 25%
NF/NF= Heterozygous for frame 50%
FF= Homozygous FOR for frame 25%

So like I said you have a good chance of making a lethal white foal from your mare if she is frame and you breed to frame. And you might think oh I only have a 25% chance of death there's a 75% chance my foal will be normal. Not saying that you would just chance it but unfortunately there are breeders out there that do this, but I say taking any chance which would knowingly cause death is wrong and irresponsible. And not only costly to the owner but physically and emotionally costly to the mare as well. 

Now here's a real life case for some of you who may not have seen it. This is my friends QH mare who doesn't necessarily scream frame. To most including her owner no one really thought much about her having frame she had two brown eyes and is solid colored exempt for a blaze which slightly goes over one of her eyes and a small white spot on her side. Well she bred her mare to a frame carrying stud. I mentioned to her that I wondered if her mare had frame due to her irregular blaze and side spot. But she said she didn't know and she like many others considered it a "paint" problem. Well I talked to her more about it but she didn't seem to worry so I just dropped it. Well her mare had her baby a few weeks back and she text me and told me that the baby was stuck for a bit and then it died right after birth as she was upset. And then she said it was a pretty colt and it was ALL WHITE. And I had her text me a pic and I said I was scared this would happen becuase low and behold a lethal white foal was born as I feared. And then I had to reexplain why the foal died which I did not enjoy. More education in the horse breeding world needs to be available. There is a lot of misconceptions about frame out there. Ok so I hope I helped and explained this well and didn't mess anything up. I'll step of my soapbox 

This is my friends QH mare









This is a link to another sad true story about frame and great and sad read that I recommend. 
Mountain Music: On the wings of an Angel
_Posted via Mobile Device_


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## Poseidon (Oct 1, 2010)

stevenson said:


> so you are saying any horse can carry it ? I have never heard of a quarter horse having lethal whites. I have not heard of this in Appys either.
> Not in Morgans , etc. I do believe that this is a Paint / Pinto genetic disorder, even though many Paints were started from quarter horses with excessive white, the Paint has breed has changed since it orgin.


My mare is registered APHA, but is 94% Quarter Horse as nearly all of her breeding is crop outs. She is N/O and her only white markings are the blaze pictured below and one small sock.


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## Peppy Barrel Racing (Aug 16, 2011)

NBEventer said:


> I know this might sound like a dumb question but I want to confirm my thoughts on this.
> 
> I have a bay belgian warmblood mare with a white sock and blaze, I am breeding her to a CSH Stallion who is a solid bay with no white. There is no chance of frame there is there?


Yes frame doesn't always have a physical characteristic that can be seen. Which has to do with dominance of genes and such. It's like when people carry genetic diseases or defects that they themselves don't have due to the masking effects of dominant genes over recessive ones but some of thier children inherit the recessive gene/genes and are afflicted the the disease or defect.
_Posted via Mobile Device_


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## Peppy Barrel Racing (Aug 16, 2011)

Now just so you know horses who are born almost completely white may not be lethal white foals, there are max sabino and dominant white horses who are born almost completly white that of course have no problems, though these horse can carry a frame gene. My gelding is an example of a genetically non grey almost completely white horse. He's my APHA paint Pepper Sonnys Butch Cassidy Paint if your interested in his breeding. He is registered as a chestnut Overo but his coat pattern is definitely max sabino but that is an "Overo" pattern. Besides some red ticking on his ears, neck, shoulders, hind quarters, and some red hairs in his mane and tail the rest of him is white. So he is almost all pink skinned except for areas of black mottled skin pigmentation where the red ticking is. Now if in some theoretical situation where I wanted to maybe breed him (can't actually he is gelded and not stud material anyways) I would definitely have him tested for Frame. Even though neither of his eyes are blue I know for certain that his mother is a probably a frame carrier because of her one blue eye and the white pattern in her face. I wish I had a picture of her but I don't. Then there is pepper's sire who is a loud chestnut overo, I don't know his Frame status though but he comes from a long line of known "overo" carrying horses even though they are registered AQHA you can see from allbreed he has Sonny Dee Bar close on both sides of the family, so there is a possibility of him being frame. Sonny Dee Bar was known for having "Overo" (i hate that term) white patterns I believe the exact ones are splash and sabino not sure about frame. Feel free to enlighten me on that someone. Anyways with so much "overo" in his backround not just Sonny this gives pepper the possibily of being frame even though I can't see it.

As I was typing this I came up with a question to ask! I'd love someone to educate me! Now when Pepper was young he was a classic medicine hat paint and his ears have the most concentration of color on his body even today though there is a lot of white enterdispersed on his ears but the inside of his shows the true red with no white hairs. Anyways my question is what causes the Medicine Hat marking is it associated with Frame or multiple patterns together?









_Posted via Mobile Device_


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## Poseidon (Oct 1, 2010)

Peppy, it's usually multiple genes working together. Most have tobiano with some combination of frame, splash, and sabino. But some don't have tobiano. Something like homozygous splash and frame loud enough could cause a medicine hat. Meh. Just throwing things out there. :lol:


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## Peppy Barrel Racing (Aug 16, 2011)

Poseidon said:


> Peppy, it's usually multiple genes working together. Most have tobiano with some combination of frame, splash, and sabino.


Oh awesome thank you Posiedon I appreciate that!!! I love learning new things!


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## Breezy2011 (Nov 23, 2012)

The Lethal white foal is called Overo Lethal White Syndrome.


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## Peppy Barrel Racing (Aug 16, 2011)

Breezy2011 said:


> The Lethal white foal is called Overo Lethal White Syndrome.


I think it would be more precise to say the lethal white foal is a consequence of OLWS.


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## Reno Bay (Jul 8, 2012)

Breezy2011 said:


> The Lethal white foal is called Overo Lethal White Syndrome.


The lethal white foal is called a _lethal white foal_. The death happens due to an incomplete digestive tract caused by _Overo Lethal White Syndrome_. A foal is not a syndrome...


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## Peppy Barrel Racing (Aug 16, 2011)

Reno Bay said:


> The lethal white foal is called a _lethal white foal_. The death happens due to an incomplete digestive tract caused by _Overo Lethal White Syndrome_. A foal is not a syndrome...


That's what I just said but I must admit I like the way you said it better. It was truthful blunt but made me laugh. Way to go Reno!


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## kay56649 (Mar 25, 2012)

My mare foaled a perfectly normal foal, and the next time, she gave birth to a lethal white foal from the same stud. She had an emergency c-section and hasn't been bred since. It is to bad because her one foal is awesome and she has such a great mind!


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