Doctors cross line that modifies future generations

Infertility doctors are making news again - this time for breaking a scientific taboo, not just talking about it.

While one international team of doctors spurred outrage recently over promises to clone a human being, another team has quietly helped several families around the world give birth to babies who are the first to carry the genes of two mothers and one father.

Their experiments introduced material from the eggs of younger donors to help older women become pregnant.

The mixture of DNA will be passed to future generations, representing the first known case of "human germ-line modification." This controversial step has been off limits because of ethical concerns about the unknown consequences and the potential to open the door to "designer babies" and eugenics.

"They have breached a wall that had been erected by scientists, geneticists, and doctors who said they would never do germ-line genetic change," says Arthur Caplan, director of the Center for Bioethics at the University of Pennsylvania. "This is an ethically momentous shift."

The experiments, made public in the British journal, Human Reproduction, spotlight the rapid merging of genetics and reproductive technologies, a field which has been virtually unregulated in the US. Some ethicists now are calling for regulation of all such research on human subjects - both private and public.

The infertility treatments were carried on by highly respected doctors at the Institute for Reproductive Medicine at St. Barnabas Medical Center in New Jersey in an effort to raise the success rate of IVF treatment for older women. The highly experimental procedure involved transferring mitochondria - "the power packs" of cells - from the donors into the eggs of women whose eggs were defective.

Thirty babies worldwide have been born as a result, and tests on two babies that are now about one year old confirm that they carry a small amount of genetic material from the donor. The researchers say it was not their purpose to do germ-line modification, although they themselves touted the experiments in the article as "the first case of human germ-line modification on normal healthy children."

But ethicists and even some fertility experts say that while it may be to some degree "inadvertent," the experiment crosses the line, in terms both of taking risks and of the way they have gone about it.

"You're changing the basics of the person who is being created," says Dr. Arthur Leader, chief of reproductive medicine at University of Ottawa, quoted in the National Post. "At this point there is no reason to risk children and future generations for a therapy with no proven need."

"I think it is scandalous to try untested research techniques on human subjects," says Audrey Chapman, a program director at the American Association for the Advancement of Science, in Washington, D.C. "People should be disturbed that there has been human germ-line modification without any scientific review."

Eric Parens, an associate at The Hastings Center, a bioethics think tank in Garrison, N.Y., says the germ line is too important a line to cross inadvertently. "We need to have a public discussion," he says. "If we are going to go down the road of 'repro-genetically' shaping our children, we should do it with our eyes wide open; if we think it is a bad idea, we ought to refrain from crossing it inadvertently."

So far the children in the St. Barnabas experiments seem to be healthy, and the doctors indicate they plan to continue such treatments. This disturbs others.

"I'm glad the babies are fine, but that's a very early report," Caplan says. If something went wrong with the mitochondria, he adds, the situation could become disastrous. "You'd like to see them watch them carefully for a period of five years and then decide to keep going."

Other doctors agree that it's just not known whether there might be side effects to the procedure.

Jacques Cohen, the scientific director at the Institute, was not available for interviews. Dr. Cohen earlier told the Star-Ledger in Newark, N.J., that he didn't feel they had crossed a barrier and was flabbergasted by the reaction. He said the genes within the mitochondria are virtually identical in all people, and there should be no ill effect from the transfer.

The germ-line modification debate relates most to the alteration of DNA in the nucleus of cells, which affects the main human characteristics. This procedure did not change the nucleus, so it is not as dangerous. Still, it will alter future generations, Caplan says, "and it was reviewed by no one but four guys in New Jersey."

Dr. Chapman recently co-authored an AAAS study on the implications of human germ line modification. "We recommended that an oversight mechanism be set up immediately that would monitor and oversee research and developments," she says, adding that legislation is needed.

A major roadblock, many say, is abortion politics. That kept a human cloning ban from being passed four years ago, and it's the reason Congress has never tried to regulate reproductive technologies. A way must be found to stop mixing abortion politics into these issues, Caplan says, or "we will continue to have no oversight, regulation, or accountability."

(c) Copyright 2001. The Christian Science Monitor