USA scientists have corrected a genetic heart mutation in embryos using CRISPR

USA scientists have corrected a genetic heart mutation in embryos using CRISPR

USA scientists have corrected a genetic heart mutation in embryos using CRISPR

The work focused on an inherited form of heart disease, but scientists believe the same approach could work for other conditions caused by single gene mutations, such as cystic fibrosis and certain kinds of breast cancer.

WASHINGTON-Altering human heredity? In a first, researchers safely repaired a disease-causing gene in human embryos, targeting a heart defect best known for killing young athletes - a big step toward one day preventing a list of inherited diseases.

Mitalipov now wants to replicate the study with other mutations and other donors, to improve efficiency.

Hereditary hypertrophic cardiomyopathy occurs in about one out of every 500 adults, and is passed along when a person winds up with one good copy and one mutated copy of a gene called MYBPC3, the researchers said.

"Every generation on would carry this fix because we've removed the disease-causing gene variant from that family's lineage", Dr Shoukhrat Mitalipov, a key member of the team, said. In the same article, Hank Greely, Ph.D., director of Stanford's Center for Law and the Biosciences, pointed out that gene editing could be used to fix defective embryos before implantation, reducing the number of embryos that are ultimately discarded.

They co-authored a study published on August 3.in the scientific journal Nature, showing that a mutation linked with a deadly, hereditary heart disease can be corrected in early stage embryos using the CRISPR-Cas9 "gene editing" tool.

In a lab dish, the researchers used CRISPR, a gene-editing technique, to remove the harmful MYBPC3 mutation from the human zygotes.

Several teams in China have already reported using CRISPR-Cas9 to alter disease-related genes in human embryos.

Embryos used by the scientists were allowed to develop for five days before the experiment was stopped.

"At this stage, I would say this is still basic research", Wu said.

For the latest Nature paper, embryo experiments were conducted in the United States and led by Shoukhrat Mitalipov, a reproductive-biology specialist at the Oregon Health and Science University in Portland.

The Mitalipov-led team is the first to demonstrate error-free editing of human embryos. The study that was conducted in USA comes just months after a national scientific committee recommended new guidelines for modifying embryos, easing blanket prescriptions but urging the technique be used only for dire medical problems, the report added.

The Salk scientists and their colleagues say they never meant to implant any of the embryos used in their research, much less to bring any of those embryos to term.

Genome editing has potential for the targeted correction of germline mutations.

"Really we didn't edit anything". "Cas9 is rapidly degraded", he says.

According to the release, "There were no off-target mutations".

Not all the embryos were perfectly fixed, though: 16 showed erroneous fixes to their MYBPC3 gene. She said that characteristics that some parents might desire, such as intelligence and athleticism, are influenced by multiple genes and that researchers don't understand all the components of how such characteristics are inherited, much less have the ability to redesign them.

Medical ethicist Jeffrey Botkin, M.D., M.P.H. is available to comment on the ethics of editing genes with CRISPR in human embryos.

The timing of the CRISPR-Cas9 introduction - injecting it simultaneously with the defective sperm into the healthy egg - was also found to have raised the chances of success in gene fix. Only one was a mosaic. That meant half the fertilised embryos would be normal; half defective. In the USA, taxpayer funds can not pay for research that destroys human embryos. Mitalipov also carries the distinction of being the first to crack the long-standing problem of cloning human embryos and deriving embryonic stem cells.

From a purely research perspective, this paper is an exciting advance. "But it's still very premature". "It's unclear when we'd be allowed to move on". Since then, reports have rolled in of other clinicians performing the technique.

"This is definitely a leap forward", agreed developmental geneticist Robin Lovell-Badge of Britain's Francis Crick Institute.

The technique could be used through in vitro fertilization to cure thousands of diseases caused by mutations in single genes. In their experiments, Mitalipov's team provided a strand of DNA to serve as a template for rewriting the disease-causing mutation.

However, in a complete surprise to the researchers, this did not happen. "N$3 o matter what anybody says, this is not the dawn of the era of the designer baby".

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