Researchers at Columbia University reported the first near‑perfect edits of early‑stage human embryos using a newer technique called base editing. The team swapped single DNA letters in the PCSK9 and HBG genes, which influence cholesterol and fetal hemoglobin, without the extensive DNA damage typical of earlier CRISPR methods. The work, posted online, is pending peer‑review.

Base editing, pioneered in 2016, makes a tiny nick in one DNA strand, letting cells repair specific mutations. In the Columbia experiments, the edits succeeded in many embryos, though some showed mosaicism—mixed populations of edited and unedited cells. Critics warn that hidden risks may emerge only after birth, underscoring the need for rigorous safety studies.

Industry players see commercial potential. Nucleus Genomics, a firm that screens IVF embryos for genetic disease, will back the next research phase, aiming to eliminate mosaic embryos and test the technique on later‑stage embryos used in clinics. The study moves the prospect of repairing hereditary disorders in embryos closer to clinical reality.