Monday, September 17, 2012

Dominant White--NOT sabino

Dominant White (DW) is a dominant gene. It is also believed to be EMBRYONIC lethal in its homozygous form. Meaning the homozygous foal is never born and is aborted/absorbed by the mare early during the pregnancy, unlike Lethal White Overo, where the foal is born and will die shortly after birth.

There have now been at least 11 different Dominant White mutations found, and like they started with Sabino, all have a number i.e. DW 1, DW 2....DW 10, DW 11. Now despite the name "Dominant White" not all horses who are Dominant White are solid white. According to research most are at least 50% white.

The reason I am breaking from my pattern of going in order down the genes in my first post on this blog is because Dominant White is a new thing, and many horses previously thought to be Sabino are, in fact, Dominant white. Most notably is the Puchilingui line in Thoroughbreds.

Puchilingui himself was tested in the most recent Dominant White study, and was found to be positive for Dominant White

His son Sato, from Blazing Colours Farm, was also used in the study, and he was found to be positive for Dominant White as well.

This mare is Puchi Trap, from True Colours Farm. She is a daughter of Puchilingui, and while she was not used in the Dominant White study, based on her appearance, and her bloodlines, it is a very good bet that she is also Dominant White.

Another separate line of Dominant Whites, is the "Patchen" line. This first horse is Patchen Beauty, with her foal Patchen Prince running at her side.

This is an older photo of Patchen Prince running in a race

And here is another of Patchen Beautys foals, The White Fox. All three of these horses are confirmed Dominant White

This is Airdrie Apache. He has NOT been confirmed to be Dominant White, however his pattern, and his production record really lend credence to the theory that the Airdrie Apache line is Dominant White

This is a son of Airdri Apache named Allamystique from Reed Hill Farm

This mare is also from Reed Hill Farm, and is a daughter of Allamystique, and a grand daughter of Airdrie Apache


tollertwins said...

Do you know if dominant white has been found in Iberian or Welshies?
I have a pony cross who is white/white. Pink skin w/ small spots, white coat, white mane and tail.
Had him tested for Sb1 and he was
heterozygous - not homozygous. Not sure what else there is other than dominant white

EquineGenetics said...

Hi tollertwins, sorry I did not get to this earlier.

As far as I know Dominant White has not been found in Iberian or Welsh as of yet. However, with how many mutations have already been found, there is surely some form of Dominant White in both.

Your pony could also be homozygous for another form of Sabino, that isn't Sabino 1.

Hope this helps!

cedarrockkt said...


The filly that you have in the first picture of your site is "Mile High Party". She is a max splash/ sabino APHA - there is no chance of frame. I do not mind your using her picture- but if so would like you to link to our page (

The "dominate white" that you are talking about is a new one to me- I will have to do some digging. It seems very similar to Splash White - are they really thinking its separate from splash?

I have another colt (Victory Party) that is a full sibling in blood to Milly - his markings are very different than hers tho - more like your 'dominate white' horses - and he is the same splash/sabino.


EquineGenetics said...

Hi Kristina!

Thank you very much for the added information about Mile High Party. I will gladly add that information, along with a link to your farm to my original post.

As far as Dominant White goes, yes they are very certain it is different from Splash white. They have located multiple mutations of Dominant White, and all appear to act much differently than splash even though they appear visually similar.

A side article with very good information about dominant white is from Dun Central Station.

If you have any other questions, feel free to ask away, and I hope this information has helped.

EquineGenetics said...

Oh Kristina, is Mile High Party's dam negative for frame as well as her sire?

Thank you again!

holo makai said...

The last photo of the DW thoroughbred is not a mare. He is a stallion called "Art in Motion" by Allamystique out of Rutland Road he was bred by Reed Hill Farm. He is currenlty owned by Power Paint Farm in PA.

Kilynn said...

Just wanted to note that her seems to be a good number of DW in Marwari, Baluchi, Kathiawari, as well as other desert horses as seen in Egypt. As of yet I have seen a article on DW mention these or which DW one they cary or if its another on top of the already known 11. it is definately not maximum sabino or few spot. There are no leopard complex horses known in those areas of native horses.