CRISPR-technology should not be used to repair genes in Human Embryos
On the 10th of February Dagens Medicin featured the news that CRISPR should be kept away from human embryos. It was based on research published in Cell, demonstrating how the technology can damage the genome to an extent which the cells cannot repair. This would impose a risk of gene- and chromosome errors, which children could end up fighting for the rest of their lives.
According to Professor Eva Hoffmann, who is also part of ReproUnion, there should be no doubt that CRISPR must be kept away from human eggs and embryos in all stages of their development.
“As scientists we have been divided in two groups when it comes to CRISPR technology to repair gene errors in embryos during the first cell divisions. Some have seen it as an obvious possibility to remove disease causing genes, whilst others have been worried about the risk of introducing new gene errors in the attempt to repair others. This study points in the direction that it isn’t possible to repair human embryos with CRISPR,” said Eva Hoffmann to Dagens Medicin, following her review of the study, which was also published in Cell.
In the study scientists fertilised donor eggs from healthy women, with semen from a man who was blind due to a mutation in a specific gene on chromosome six. They then used CRISPR to attempt cutting the defect gene from the genome. Only 7% of the embryos had the gene correctly repaired, however, only in some and not all the cells. In 50% of the cases had the cells completely removed chromosome six instead of repairing it with material from the mother. Another 43% of the attempted repairs failed, mostly because the cut chromosome six had come together again, sometimes even with mutations.
The study Allele-Specific Chromosome Removal after Cas9 Cleavage in Human Embryos was published in Cell in December 2020
Here you can read the full article in Dagens Medicin (requires subscription)