Here's something interesting that happened within the sphere of my extended family. My sister-in-law had a sister that was diagnosed with leukemia, her name is Kathy. She went through the approved cancer treatments, chemotherapy and radiation, without success. Kathy progressively got sicker. She lives in Pennsylvania, born to immigrants from Poland. She was asked to participate in a study for an experimental treatment of stem cell transplant and referred to Johns Hopkins University Hospital in Baltimore, Maryland. Stem cell transplantation has been used in the past as a treatment option for leukemia and multiple myeloma with limited success.
Before Kathy began the process, she had to go through scores of test and her DNA was analyzed for family history, health risks, etc. They discovered that she had Mongolian genes in addition to those that indicated her genes were of Eastern European descent. That was a total shock to her. To make this story shorter, her stem cell transplantation was 100% successful and from what she was told by Johns Hopkins doctors, she was the
only successful patient in the study, the others didn't survive.
The donor for her stem cells was a young woman from S. Carolina. Their identities were withheld for one full year. I suppose it's to ensure that the recipient survived one full year after transplantation. After a year, she was allowed to learn the identity of her donor. They met and instantly formed a bond with each other. This young woman had a small child and has since had 2 more. This all happened about 10 years ago. She and this woman have a genuine mother-daughter relationship and visit with each other frequently. The woman's children are now like grandchildren to Kathy. It's a story that would actually make a good movie with a happy ending.
The most stunning thing to understand is that they both share the same, identical DNA now. They are as closely relation biologically as any two people could be. This young woman saved her life. She has since donated her stem cells at least twice more since 'Kathy'.
More information about DNA testing here:
Free Review of Ancestry Dna Tests | Genetics Digest