I was just wondering of homozygous roan was lethal (stillborn foal) in the game. I have a roan mare I want to breed to Blue Ensign, but not if homozygous roan is lethal. I know there’s some debate in the equine community.
I don’t believe that’s factored in. We don’t have any lethal white foals here, either. It’s just random numbers. Breed away. =)
The only risk of death in breeding is the risk of mare death in foaling, and a stillborn foal (which is independent of genetics).
I think homozygous roan is still undecided as to whether it’s lethal, and we don’t have the white gene in the game, so no worry about lethal white syndrome. 
Good luck with your baby!
That’s good to know!
As far as I’m aware, there’s only one line of roans (they’re quarter horses, I think) that has proven to be homozygous roan. I’m not sure it’s been found in any other line.
I’d looooove to have overo (and cream, and splash, and sabino) in the game! Roan is even rarer in TBs than overo and the others (there are maybe 20 true roan TBs? I think Catch a Bird only had 4 roan foals, and they were a first). I’m such a color nerd!
Yeah, I don’t think roan existed in TBs until Catch A Bird showed up.
I may refactor the genetics a bit at some point, but only after I redid graphics. Which would be after I rewrote all the code. 
So…a while.
Umm, Shanthi, lethal white syndrome is associated with frame (OV) not white (W) 
.
flees
And Catch a Bird is a mutant freak.
I blame jet lag. Yep. 
(Swear I knew that, really.)
Never said he wasn’t , but the roan had to come in somewhere, and it happened via mutation in the TB.
Well… they think homozygous Dominant white (which does exist in TBs) is lethal in utero.
And I agree. What a weirdo.