U.S. scientists from Oregon Health and Science University (OHSU) have succeeded in altering the genes of a human embryo to correct a disease-causing mutation.
Scientists used a technique known as CRISPR-Cas9 to correct a genetic mutation for hypertrophic cardiomyopathy.
CRISPR is an abbreviation of Clustered Regularly Interspaced Short Palindromic Repeats. A simple version of the CRISPR/Cas system, CRISPR/Cas9, has been modified to edit genomes.
CRISPR-Cas9 works as a type of molecular scissors that can selectively trim away unwanted parts of the genome, and replace it with new stretches of DNA.
Scientists introduced the genome editing components along with sperm from a male with the targeted gene defect during the in vitro fertilization process. They found that the embryo used the available healthy copy of the gene to repair the mutated part.
The Salk/OHSU team also found that its gene correction did not cause any detectable mutations in other parts of the genome – a major concern for gene editing.
Still, the technology was not 100 percent successful. It increased the number of repaired embryos from 50%, which would have occurred naturally, to 74%.
The embryos, tested in the laboratory, were allowed to develop for only a few days.