In my wife's case, back in 1996, they didn't waste a minute. As soon as she was diagnosed they tested her siblings, her mother, her aunts/uncles, our children, and even me! We all got blood tests in the same lab at the hospital where my wife got her CBCs.
In hindsight I think they were overambitious testing so many relatives. Why they tested me I don't know (we're certainly not blood relatives!
) but all of the testing was covered by her insurance.
Despite all that, nobody matched her HLA type and her transplant 2 years later (after ATG failed to produce a lasting response) was from an unrelated donor, one of two found in the
Be The Match Registry of the National Marrow Donor Program. They found those two the very first time they searched.