The Facts and Fiction of Cloning
Understanding the real science behind the headlines and the hubbub.
But some researchers doubt that this technique for human cloning could ever be used for widespread treatment of disease.
"The great vision of this field is to create personalized stem cells for individual patients," says Griffin. "You'd take the cell from the patient and create the cell type you want -- say pancreatic islet cells for diabetics -- by transferring it to an egg, creating an embryo, and growing them."
"If there were enough women to donate enough eggs, and enough [funding], I'm certain it could be done," says Steven Stice, PhD, professor and GRE Eminent Scholar at the University of Georgia in Athens. "But we collect hundreds of eggs a day from cattle to do our cloning. You could never expect to do that in humans. Technically, it's not feasible."
"In the U.K., 120,000 people suffer from Parkinson's disease. Where are you going to get 120,000 human eggs? The reality is that there simply are not enough eggs ... available to make therapeutic cloning a practical, routine therapy," says Griffin.
And offering women money would still not yield the necessary numbers. The egg-harvesting process is just too uncomfortable. "Egg donation is akin to bone marrow transplantation as far as how unpleasant the process is for the donor," says Griffin.
And then there's money. "You'd have to produce an individual cell line for each person to avoid the immune response," says Stice. "The cost would be horrendous. It will be very difficult to get to an application [of the technology] that won't cost hundreds of thousands of dollars [each time]."
In the end, both experts agree that therapeutic cloning is really unnecessary, given the existing supply of viable embryos left over from in vitro fertilization. "They would be discarded," says Stice. "They're donated with consent, and would never have gone on to form an individual. There are great opportunities with existing cell lines to get to the point of treating disease. We don't have to go to [cloning]."
So why continue? Because of the wealth of information it can provide, says Griffin.