Korean team clones embryos

The method, therapeutic cloning, is one of the great hopes of the stem cell field. It produces stem cells, universal cells extracted from embryos that, in theory, can be directed to grow into any of the body’s cell types.

Because the stem cells come from embryos that are clones of individuals, they would be exact genetic matches. Scientists want to obtain such stem cells from patients with certain disorders and illnesses to study the origin of diseases and to develop replacement cells that would be identical to those a patient has lost in a disease like Parkinson’s.

Hwang said he has no intention of using the method to produce babies that are clones. ‘‘Our proposal is limited to finding a way to cure disease,’’ he said.

Previously the same group produced a single stem cell line from a cloned embryo, but the process was so onerous that many scientists said it was not worth trying to repeat it.

‘‘It is a tremendous advance,’’ said Dr Leonard Zon, a Harvard Medical School stem cell researcher and president of the International Society for Stem Cell Research.

The Korean researchers produced stem cells that were exact matches for 9 of 11 patients, including eight adults with spinal cord injuries and three children — a 10-year-old boy with a spinal cord injury, a 6-year-old girl with diabetes and a 2-year-old boy with congenital hypogamma-globulinemia, a genetic disorder of the immune system.

But the report raised concerns among others. Dr Leon Kass, chairman of the President’s Council on Bioethics, said in an e-mail that ‘‘whatever its technical merit, this research is morally troubling: It creates human embryos solely for research, makes it much easier to produce cloned babies, and exploits women as egg donors not for their benefit.’’ —NYT