Forbidden tests: panel seeks ban on human clones. (Science News This Week).

A national advisory panel has asked Congress to forbid cloning aimed at creating a child but urged the lawmakers to permit other medical experiments with cloned human cells.

Specifically, the Jan. 18 recommendation calls for a "legally enforceable ban" on placement in a woman's uterus of a human blastocyst derived from the procedure known as nuclear transplantation. A blastocyst is a multicellular stage of development that occurs after an egg is fertilized and before it's considered an embryo. In nuclear transplantation in animals, researchers place DNA from an existing animal inside an egg they've stripped of its own DNA. The egg is then tricked into dividing, as if fertilized.

The panel is sponsored by the National Academies in Washington, D.C., four nonprofit scientific-advisory groups. It recommends that nuclear transplantation remain available to scientists studying embryonic stem cells. Since stem cells have the potential to develop into a variety of tissues, such cells have shown medical promise as replacements for dying tissue. Scientists would use cloning for such purposes by putting the nucleus from a person's cells into a human egg and deriving stem cells from the blastocyst. This procedure is called therapeutic cloning.

The new recommendation falls in line with the United Kingdom's December 2001 ban on human reproductive cloning but not therapeutic cloning. On Jan. 18, a British Court of Appeals upheld a distinction between the two. Robert May, president of the Royal Society in London, hailed the unanimous three-judge affirmation as an "admirably sensible" move that will "permit legitimate uses of cloning technology in research while outlawing any attempts to carry out human reproductive cloning."

According to U.S. law, experiments on human reproductive cloning remain legal, but federal funds can't be used.

Any attempt to clone a human being would be dangerous for the woman and child and likely to fail, says Irving L. Weissman of Stanford University, who chaired the panel that wrote the report. He adds that only a small percentage of attempts at animal cloning results in the birth of healthy animals (SN: 10/20/01, p. 250).

The scientific panel recommends that a federal ban on reproductive cloning remain in place for 5 years. At that point, the prohibition should be reviewed only if new scientific evidence indicates such cloning is safe and a "broad national dialogue on societal, religious, and ethical issues suggests that a reconsideration of the ban is warranted," the panel says.