Japan moves to ban gene editing for human reproduction

Japan is preparing to outlaw research and medical procedures involving the genetic modification of human fertilized eggs using genome-editing technology when intended for childbirth.

The proposed legislation, approved by the cabinet on April 10, would require researchers to report their plans and maintain detailed records of any work involving genetically edited embryos.

While gene editing holds potential for preventing hereditary diseases, it has also raised significant concerns over unforeseen risks and technological limitations. Critics warn that it could open the door to so-called "designer babies," in which traits such as height, appearance, or athletic ability are pre-selected through genetic manipulation.

Currently, the implantation of genetically edited embryos into a human uterus is restricted in Japan under government guidelines, but these rules lack enforceable penalties. By contrast, countries such as United Kingdom, Germany and France have already implemented formal legal bans on such practices.

The new bill would also cover the use of genetically modified unfertilized eggs or sperm, introducing penalties of up to 10 years in prison and/or fines of up to 10 million yen (approximately $62,800).

Under the proposed framework, the ban specifically targets genetic editing conducted for implantation into a female uterus and the subsequent birth of a child. Research itself would remain permitted, but scientists would be required to submit detailed proposals to the government. They would then be prohibited from editing, receiving, or importing genetically modified embryos for 60 days following approval.

Much of today’s gene-editing work focuses on somatic cells rather than reproductive cells such as eggs and sperm. This type of editing allows scientists to alter genes in specific tissues without passing those changes on to future generations.

Efforts to develop so-called "designer babies" are often framed around preventing inherited diseases. However, although technologies such as CRISPR-Cas9 exist, experts caution that they are not yet safe or reliable for widespread human use, as applications in humans remain experimental and largely confined to trial phases.

By Nazrin Sadigova