UC Davis tested Homozygous for tobiano gene. Standing at Silvertip Paint and Quarter horses in Canada http://www.freewebs.com/silvrtip/stallions.htm

"Twice" is a 2001 palomino homozygous tobiano stallion. Twice has done really well for himself in Nevada and is leaving behind some really happy custumers. His breeding is phenomenal and he has crossed really well with our mares.
 
Twice is the ONLY breeding stallion off of Trophys Legend, and he is the only foal in Canada off of Trophys Legend. Trophys Legend was only used for two seasons until his untimely death from colic. Twice was bred by Shawna & Scott Hobson Located in the Columbia Basin of Washington State, Hobson. They have been specializing in Homozygous Tobiano Paint Horses for 34 years. Their Senior Stallion, Spooks Trophy Boy (Twice’s Grand Sire), produced the first female homozygous horse in the World to be documented by the Portland State Univ. and they became one of the founders in producing the "Homozygous Horse".
 
“Our Offspring are known for conformation, disposition, color pattern, and the athletic ability to do whatever you want in the way of performance.  We have some of the nicest halter, pleasure, reining, English, working cowhorse and endurance horses ever produced in today's Paint Horse World.  Our horses are sought after because of their size, bone structure, beautiful heads and their ability to learn quickly.  Most of our Foals reach 16 hands by the time they are 2 years old.”