Mosaic Problem Stands in the Way of Gene Editing Embryos
March 15, 2017
(New Scientist) – The team managed to correct mutations in three out of six embryos, suggesting CRISPR repair is more efficient in viable embryos. “It does look more promising than previous papers,” says Fredrik Lanner of the Karolinska Institute in Sweden. However, the study highlights a further roadblock to using gene editing to create healthy babies. Two of the edited embryos were mosaics – mixtures of edited and unedited cells. The team injected the CRISPR machinery when the embryos were just single cells, but it seems that, in these two embryos, it didn’t make repairs until after they had replicated their DNA. So when they divided, some cells inherited unrepaired DNA.