There was a story about a white Marine of a German derivation I think and an Asian woman who were a genetic match. He gave her a kidney or something then later they got married. It was on FR but don't remember when it came out. Sometimes I wonder if the organ transplant system needs to be more refined.
I suspect it is being continuously refined. I'm sure as the instruments for genotyping get cheaper and faster that more and more accurate genetic matches will be made. We are just in the very infancy of the use of DNA/genetic knowledge in the treatment of disease.