The blood, collected at birth, contains stem cells that can differentiate into other types of blood cells. Until now, its use has been limited to rebuilding a disease-free blood system in children with leukemia or lymphoma, instead of using a bone marrow transplant. The cord blood in such cases must come from a donor.
But there is some evidence that cord blood may also contain cells that, though not as versatile as embryonic stem cells, can transform into tissues such as heart, nerve and pancreas cells. So they may be useful for replacing or repairing such tissues if the donor develops some disease.
In addition to the Duke trial for cerebral palsy, doctors at the University of Florida have begun studying whether cord blood infusions benefit children with Type 1 diabetes. A clinical trial using cord blood to treat traumatic brain injury in children is about to begin in Houston.
And preliminary research projects in the lab and in animals have tapped cord blood stem cells as potential treatments for heart valve defects and hearing loss.
Some scientists see real promise and, like the Hextells, believe that more families should consider private storage of their babies' cord blood.
"I think the sky is the limit with umbilical cord blood," said Dr. Michael Haller, an assistant professor of pediatric endocrinology at the University of Florida, who is conducting the study on juvenile diabetes.
Animal studies helped persuade Dr. Joanne Kurtzberg, one of the foremost researchers on cord blood transfusion, to conduct a trial on children whose cord blood had been banked at birth. Studies in rabbits showed that cord blood injected into the animals' bloodstreams traveled to their brains and lessened symptoms of a cerebral-palsy-like condition.
Dallas became the ninth child in Kurtzberg's 40-person trial. Infusion of the cells through an IV cost the Hextells $15,000 and took 20 minutes. Then they flew back to Sacramento.
"She told us not to expect anything," Cynthia Hextell said. "But this gave us hope."
A week later, Hextell said, Dallas was noticeably more alert and said his first word, "Mama."
Within a few weeks of the transfusion, his nystagmus -- spasms of the eye -- disappeared, the Hextells said. Five months later, he could stand.
A month after that, he took his first steps on the front lawn while his parents were taking down their Christmas lights. "Quick, go get the video camera," Cynthia shrieked.
