Pic, Reno? I would love to see one :) Sometimes large stars can be caused by frame, it depends on the placement of the star itself of course and frame is known to be in the TB breed (just uncommon - but how uncommon is it REALLY when frame doesn't express much if at all without another pattern gene?) - a large high-set star may indeed be caused by frame. Or it might just be a normal face marking, though the theory goes that all white on any horse is due to some pinto gene or another, and it just depends on which one they have as to the expression of it. I have a theory on expression that goes along the lines of there are white suppressing genes, and they're incomplete dominant, so if the horse gets one, its white is suppressed some, but if it gets two, its white is suppressed a LOT. Sort of like cream where with one copy it's diluted a little, and with two it's diluted a lot. Some breeds have more of them than others. Explains crop-outs, and tobianos that hide! AND why, even though Arabians have been bred for a little white but not a lot for MILLENNIA, sabino and to a lesser extent splashed white are both present in the breed. High levels of white suppression, which minimises the white pattern genetics in the breed, but doesn't remove them altogether.
A while back a thread was posted on here demonstrating how tobiano can hide, and pics were posted of genetically tested homozygous tobianos that were completely solid. No white to speak of. It can totally hide! Tobi doesn't cause face white at all, but it CAN affect it if another pattern gene puts it there.
Last edited by blue eyed pony; 07-12-2012 at 04:08 PM.