New Stem Cell Source Confirmed

 Bob Lanza and his team at Advanced Cell Technology announced recently that they found a way to derive embryonic stem cells from a single cell without destroying an embryo.  They were proposing that scientists could take advantage of this discovery by using cells already being extracted from embryos during a technique called pre-implantation genetic diagnosis, or PGD. The technique allows fertility clinics to choose the embryos most likely to lead to a healthy baby. If parents undergoing treatment agreed to donate that single cell used for diagnosis (which is otherwise tossed), scientists would have a whole new, and presumably ethically acceptable, source of material from which to derive embryonic stem cells.

Lanza repeatedly tried to make it clear that this technique is already performed at clinics across the country. But religious leaders and senators seemed to have a hard time understanding that.

A study from the Johns Hopkins Genetics Policy Institute might help. Researchers there have found out how often PGD is performed in the United States, and what it's used for:

Nearly three-quarters of in vitro fertilization clinics offer PGD.

PGD is used in up to 6 percent of IVF cycles.

Clinics reported performing 3,000 cycles of PGD in 2005. (according to the CDC, more than 100,000 cycles were reported in 2001 -- assuming the numbers stay about the same annually that would be more than 6,000 cells that could provide embryonic stem cells every year, based on the 6 percent figure above).

Two-thirds of all PGD cycles in 2005 were for chromosomal abnormalities that cause miscarriages or birth defects.

Forty-two percent of clinics performed PGD for sex selection

Twenty-three percent have performed PGD in an attempt to produce a child immunologically matched to a sick sibling.