Cambridge, MA - A prominent American scientist is warning against a backlash to the claim that a Chinese scientist has helped make the world’s first gene-edited babies.

Harvard Medical School dean Dr. George Daley says it would be unfortunate if a misstep with a first case led scientists and regulators to reject the good that could come from altering DNA to treat or prevent diseases.

Daley spoke Wednesday at an international conference in Hong Kong, where the Chinese scientist, He Jiankui (HEH JEE-ahn-qway) of Shenzhen, also is scheduled to speak.

He says his lab used the powerful gene-editing tool CRISPR to alter the DNA of human embryos to try to help them resist possible future infection with the AIDS virus. He said twin girls with the altered genes were born earlier this month.

There is not yet independent confirmation of his claim, but scientists and regulators have been swift to condemn the experiment as unethical and unscientific.

The National Health Commission has ordered local officials in Guangdong province to investigate He’s actions, and his employer, Southern University of Science and Technology, is investigating as well.

The Chinese researcher said he practiced editing mice, monkey and human embryos in the lab for several years and has applied for patents on his methods.

He said he chose embryo gene editing for HIV because these infections are a big problem in China. He sought to disable a gene called CCR5 that forms a protein doorway that allows HIV, the virus that causes AIDS, to enter a cell.