Designer Baby On Way? US Scientists Modify Genes Of Human Embryo

Designer Baby On Way? US Scientists Modify Genes Of Human Embryo

Designer Baby On Way? US Scientists Modify Genes Of Human Embryo

An worldwide team of researchers has used CRISPR-Cas9 gene editing - a technique that allows scientists to make precise changes to genomes with relative ease - to correct a disease-causing mutation in dozens of viable human embryos.

Scientists at the Salk Institute in collaboration with colleagues in OR and South Korea have succeeded in correcting a disease-causing mutation in human embryos through gene editing.

The medical milestone announced Wednesday involved the use of a gene editing technique called CRISPR-Cas9 to remove a genetic mutation for a heart condition and replace it with a healthy version of the gene in viable human embryos. That's encouraging for one potential use of CRISPR in the future as a way to correct inherited genetic disease, says Mitalipov, since the embryo seems to have a built-in, reliable way of repairing the injury caused by splicing out an abnormal gene. They applied CRISPR at the earliest stage possible-when the embryo is still a single cell-to ensure that the genetic changes they introduced were propagated to every cell of the embryo as it divided and developed.

Forty-two (72.4 percent) of the resulting embryos contained two mutation-free copies of the MYBPC3 gene.

Federal agencies also ban funding of research that ultimately leads to the destruction of human embryos in research. This happens when CRISPR's genetic scissors make cuts to the genome in places the scientists weren't aiming for. About 40 nations, including the United States and the United Kingdom, effectively prohibit or outlaw using the method to genetically engineer babies. The discovery could mean that it will be hard for researchers to fix mutations in embryos if neither parent has a healthy copy of the gene.

Researchers reported no adverse affects in the unaltered DNA of the donor embryos.

The scientists say had the embryo been allowed to mature, the successive generations would have been free from the faulty gene.

He pointed to gene therapy trials for disorders such as sickle cell disease and cancer that show promise for treating hard disorders.

THE NEWS that researchers have carried out the first known attempt to create genetically modified human embryos is another signpost in an astounding revolution unfolding before our eyes. "With this particular mutation, we've already done the groundwork, so we're probably much closer to clinical applications", Mitalipov said during a conference call with journalists.

The procedure was most effective when CRISPR-Cas9 was injected into the eggs along with the sperm rather than immediately after.

The most recent work is particularly sensitive because it involves changes to the germ line - that is, genes that could be passed on to future generations.

Lanner is also editing genes in human embryos, as a way of learning more about developmental biology.

"It may be that some countries never permit germline genome editing because of moral and ethical concerns", said Professor Joyce Harper from University College London. "This would completely eradicate the gene mutation and this disease from the lineage of a family", Mitalipov says.

However, the authors say that, by increasing the number of healthy embryos from 50% to 70%, their work could provide couples with a larger number of healthy embryos, improving the chance of successful IVF. "The other barrier is, the (US Food and Drug Administration) is prohibited from considering any clinical trials related to germline genetic modification", she said. Last year, Britain said some of its scientists could edit embryo genes to better understand human development.

Though the researchers have expressed enthusiasm around their new study, they also noted that the findings must be replicated in followup research before this gene-editing approach can move forward to clinical trials. Genes in which dominant mutations manifest as late-onset adult disorders include BRCA1 and BRCA2, which are associated with a high risk of breast and ovarian cancers1, and MYBPC3, mutation of which causes hypertrophic cardiomyopathy (HCM) 2.

Sperm from a man with hypertrophic cardiomyopathy was injected into healthy donated eggs alongside Crispr technology to correct the defect.

The procedure was conducted on embryos created in the lab for the objective of testing the CRISPR-Cas9 treatment.

In this case, scientists can analyze the embryos in vitro to weed out any with the genetic defect before implantation into the womb.

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