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Homozygous Compound or Double Splash?

One thing that has been bothering me recently since the splash paper released is the naming system for horses with 2 splash alleles. Most are just called homozygous splash, and outside of the stock horse world it seems accurate since SW1 is the most common mutation. But with SW2 and SW3 they can also cause the same visual expression, but are different genes. And SW2 is on the PAX3 locus while SW1 and SW3 are on the MITF locus. The term compound splash was used in horses with SW1/SW2 genotypes and seems more appropriate, and in layman's terms double splash seems appropriate as well since it is self explanatory for the most part. Since 'triple splash' horses are possible and other unidentified splash mutations are likely, the term homozygous splash doesn't seem to fully cut it anymore for horses of that phenotype. What are your thoughts?

RiddleMeThis Wed, 04/25/2012 - 07:45

I think just calling the ones who are SW1/SW2 or SW2/SW3 "Splash White" is the most appropriate and then going into details about the actual genetics of it.

rodeoratdogs Mon, 04/30/2012 - 23:05

I would have to agree with Threnody that there needs to be a name that is easy for us lesser educated people to get it ok. It just would be easier than saying um that horse is a Homozygous splash, but that other horse over there is just a splash, nevermind it has just as much white as the first one, just trust me ok..... Wait a minute, did I just call myself stupid?? Well you get my point at least...I hope.

Pacific Pintos Sat, 07/07/2012 - 19:10

I agree that we need to explain which SW gene we are talking about.

On my website I will state that the horse is positive for SW-1 or homozygous for SW-1. Miniatures do not have the SW-2 or SW-3 genes as yet.

My only issue is the number of horses we are finding that have classic SW patterns and yet are testing negative.

:BH