Stem Cell Siblings

But preimplantation genetic diagnosis (PGD) was.

PGD is a technique that allows parents who are carriers of a genetic disease to have a healthy child by screening embryos for genetic diseases. It may help in preventing pregnancy terminations.

"This has never been done before in the world," says Nash. "We were the first family to do PGD for Fanconi Anemia, and to also have a baby that was healthy, and a bone marrow tissue type to match Molly."

Adam Nash wasn't just their newest child; he was also a donor for his sister Molly. He was born after doctors fertilized several of Lisa's eggs, but only implanted one that was both genetically healthy and a match as a donor. Blood from Adam's umbilical cord was used to cure Molly.

"This is the beauty of doing PGD; Adam was never touched in saving Molly's life and giving Molly a second chance at a healthy life," says Nash. "Adam's cord had been cut, my placenta had been delivered— the placenta which is usually garbage… They took this garbage, collected the cord blood, the placenta stem cells, and that's what Molly received as her transplant and her second chance on life."

The Nashes say that some have critized their decision, but they are thrilled with their family. Molly is now a healthy little girl who received the best gift any sister could get from their brother, life.

Verlinsky's research was published in the May 2005 issue of the Journal of the American Medical Association, and was funded by the Reproductive Genetics Institute.