This summer, American scientists reported successfully editing out a harmful gene from the genomes of human embryos.
Researchers led by Shoukhrat Mitalipov—a reproductive biology specialist at the Oregon Health and Science University—used CRISPR gene editing to achieve this result. The process enables biologists to precisely cut out and replace bits of the DNA that make up the genes of microbes, plants, and animals. In this case, the researchers mended a deleterious gene variant that causes enlarged hearts and often results in sudden death early in life.
Unlike earlier research in China, the Oregon team reported getting the repaired genes into every cell in 42 out of the 58 embryos they edited. In most of the cases, the process did not create new off-target mutations. Since Congress has banned the National Institutes of Health from funding research using gene-editing technologies in human embryos, this proof-of-concept research was underwritten by private foundations and universities.
The embryos developed for three days and were never intended to be used to create pregnancies.
Other researchers a month later challenged the results, suggesting that they need further validation. But for now Mitalipov stands by his findings, writes Ronald Baily for Reason.