Scientists urge caution on human gene editing

An international group of scientists and ethicists said this week that it would be “irresponsible” to use a powerful tool for editing human genes until more is known about the consequences and ethics of passing genetic changes to future generations.

At the close of the three-day International Summit on Human Gene Editing in Washington, D.C., participants urged caution in moving forward with “any clinical use” of human gene editing — “unless and until the relevant safety and efficacy issues have been resolved” and “broad societal consensus” is reached on the issue. They also said the practice should take place only under “appropriate regulatory oversight.”

Tools to precisely edit genes inside living cells, especially a cheap and easy-to-use mechanism called CRISP-Cas9, are transforming biology. Potential treatments include a possible cure for sickle-cell anemia, and new ways to fight HIV and cancer. But this so-called germline editing — which can involve manipulating sperm, eggs or embryos — wouldn’t affect only a patient, but also his or her descendants.

And depending on how gene editing is used, it also could alter human...