For many of those patients, especially minorities, the odds of finding an outside donor have been pretty low.
But, that is starting to change.
There is new research that suggests the donor pool may be widening.
Just shy of his second birthday, little Elmor Bonilla has overcome obstacles and odds most people don't face over a lifetime.
Elmor was born with Krabbe Disease; a rare and often fatal disorder that attacks the central nervous system.
His best shot at survival is a bone marrow transplant immediately.
Despite no donor matches in his family, and only a thirty percent chance of finding a match from an unrelated donor Elmor got his transplant, not from bone marrow, but umbilical cord blood.
It too contains stem cells patients need.
"Cord blood can be as good as bone marrow transplantation," said transplant specialist Dr. Vinod Prasad.
Even better, it may be available to more patients because it doesn't require a close match.
A Duke University study found children who received mismatched cord blood from unrelated donors had results similar to those who received unrelated matched bone marrow transplants.
"I would expect and hope that this analysis and analysis of other centers would encourage more transplant physicians to consider mismatch cord blood as a potential source of graft for more and more patients," said Prasad.
Patients like Elmor, who came through the procedure with flying colors, and is now ready to tackle being two!
The cord blood used in little Elmor's transplant came from a public donor bank.
The Duke researchers say the findings support cord blood as the stem cell source with the greatest potential to offer a transplant to almost every patient who needs one - regardless of race.
Cord blood is now being used to treat many of the same diseases that require a bone marrow transplant in children and in adults.