Overview
- A Columbia team led by Dieter Egli posted a preprint on Friday reporting that they performed precise base edits in very early human embryos.
- The researchers used base editing to substitute single DNA letters without making double‑strand cuts, a method designed to lower some risks linked to CRISPR‑Cas9.
- The experiments targeted PCSK9, a gene tied to LDL cholesterol, and HBG1/HBG2, genes involved in fetal hemoglobin production.
- Results showed mosaicism, meaning not all embryonic cells carried the intended change, and the authors said they did not evaluate long‑term safety or endorse clinical use.
- Coverage has prompted scientists and ethicists to call for wide public discussion and clearer rules, with the 2018 He Jiankui case cited as a caution about rushing heritable edits.