To add fuel to the white tiger debate (not just at this zoo but in general), a cat geneticist who has worked on snow leopards in Mongolia is not starting a project to test the DNA of white tigers in America. The purpose, I assume, is to check the diversity (for breeding, etc). He will be speaking at the Feline Conservation Federation annual convention in Cincinnati next month.
When his findings come through, it will be interesting to see the results. The FCF (of which I am a member) maintains that the previous problems of inbreeding have been largely resolved through outbreeding with orange tigers and the white tigers being born now do not suffer the same health problems as earlier generations.