HONG KONG — A group of leading scientists has declared that it’s still too soon to try making permanent changes to DNA that can be inherited by future generations, as a Chinese researcher claims to have done.

The scientists gathered in Hong Kong this week for an international conference on gene editing, the ability to rewrite the code of life to try to correct or prevent diseases.

Although the science holds promise for helping people already born and studies testing that are underway, a statement issued Thursday by the 14-member conference leaders says it’s irresponsible to try it on eggs, sperm or embryos except in lab research because not enough is known yet about its risks or safety.

The conference was rocked by the Chinese researcher’s claim to have helped make the world’s first gene-edited babies, twin girls he said were born earlier this month. Conference leaders called for an independent investigation of the claim by He Jiankui of Shenzhen, who spoke to the group Wednesday as international criticism of his claim mounted.

There is no independent confirmation of what He says he did. He was scheduled to speak again at the conference on Thursday, but he left Hong Kong and through a spokesman sent a statement saying “I will remain in China, my home country, and cooperate fully with all inquiries about my work. My raw data will be made available for third party review.”