Stem-cell breakthrough may resolve the impasses

Anxious parents and pediatric researchers alike look to stem-cell research for its potential to ameliorate or cure a host of childhood disorders and disabilities-from juvenile diabetes to traumatic brain injury. Those hopes have been stymied by the persistent refusal of the federal government to fund research on stem-cell lines derived from human embryos.

Last month, however, there seemed to be new hope: Robert Lanza, medical director of a company called Advanced Cell Technology, reported in Nature a new technique for growing a stem-cell line from a single embryonic cell (called a blastomere) removed from frozen, eight-cell embryos donated by patients at fertility clinics. Removal of single cells for what is called pre-implantation genetic diagnosis is a practice used in some fertility clinics that does not seem to jeopardize the survival of the embryo. If the embryo is not harmed or destroyed, ethical objections to embryonic stem-cell research would seem no longer valid. With that roadblock removed, proponents hoped, research could now proceed.

As it turned out, the matter was not so simple. First, there was the foofaraw over the press release from Nature announcing the discovery, which gave the impression that the embryos from which the blastomeres had been removed had survived intact. In fact, they had been destroyed, something acknowledged in the article but elided in the press release. And even if proponents of the research get over that hurdle by pointing to the viability of embryos that have undergone pre-implantation genetic diagnosis, determined opponents are still not persuaded that this is a permissible technique.

So the controversy continues.