DNA breakthrough: Scientists repair genes in human embryos to prevent inherited diseases

This sequence of images shows the development of embryos after co-injection of a gene-correcting enzyme and sperm from a donor with a genetic mutation known to cause hypertrophic cardiomyopathy. (OHSU)

In a major scientific breakthrough, researchers have harnessed a gene-editing tool to correct a disease-causing gene mutation in human embryos, preventing the mutation from passing to future generations.

In the stunning discovery, a research team led by Oregon Health and Science University reported that embryos can fix themselves if scientists jump-start the process early enough.

There was no indication how soon ordinary patients could take advantage of this technique.

The new technique, which was tested on clinical-quality human eggs, uses the CRISPR-Cas9 gene-editing tool to target a mutation in nuclear DNA that causes hypertrophic cardiomyopathy, according to the researchers. Hypertrophic cardiomyopathy is a common genetic heart disease that can cause heart failure and sudden cardiac death. The disease affects approximately 1 in 500 people and is a common cause of sudden heart failure in young people, particularly young athletes.

The research was published Aug. 2 in the journal Nature.


While the procedure is nowhere near ready to be tried in a pregnancy, the research suggests that scientists might alter DNA in a way that protects not just one baby from a disease that runs in the family, but his or her offspring as well.

“Every generation on would carry this repair because we’ve removed the disease-causing gene variant from that family’s lineage,” said the report’s senior author, Dr. Shoukhrat Mitalipov, director of OHSU’s Center for Embryonic Cell and Gene Therapy, in a statement. “By using this technique, it’s possible to reduce the burden of this heritable disease on the family and eventually the human population.”

The research offers fresh insight into a technique that could apply to thousands of inherited genetic disorders affecting millions of people worldwide, according to the experts.

The team programmed the CRISPR-Cas9, which acts like a pair of molecular scissors, to find that mutation — a missing piece of genetic material. Researchers injected sperm from a patient with the heart condition along with those “molecular” scissors into healthy donated eggs at the same time. The scissors cut the defective DNA in the sperm.