Crispr first as disease-causing mutation edited in human embryos

Crispr first as disease-causing mutation edited in human embryos

Crispr first as disease-causing mutation edited in 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.

A team of scientists led by Shoukhrat Mitalipov at Oregon Health and Science University announced this week that they used a technology known as CRISPR to edit sections of the human genome, performing the procedure on embryonic humans.

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. HCM is a disease of that causes an abnormal thickening of the heart muscle but can cause no symptoms and remain undetected until it causes sudden cardiac death. In addition, the National Institutes of Health does not fund research on human embryos, which is where CRISPR is most effective at preventing disease.

It is illegal in the United Kingdom to edit human embryos for anything other than research that is appropriately justified and supported by rigorous scientific and ethical review.

Further research is needed to determine the technique's safety, and to boost its accuracy to as close to 100 percent as possible before it can be used to create embryos meant to develop into healthy babies.

During the OHSU experiment, the CRISPR-Cas9 tool cut out the bad gene - and then the embryo replaced it with a copy of the good gene it had inherited from the mother.

Research using human embryos is highly regulated, and is different between countries. A patient with this mutation donated his sperm and skin cells for the study.

CRISPR-Cas9 works as a pair of genetic scissors created to cut the DNA near the position of the mutation and correct the hypertrophic cardiomyopathy mutation carried in the DNA of the sperm, it said.

In December 2015, an worldwide group of scientists convened by the us national Academy of sciences (NAS) in Washington had estimated that it would be "irresponsible" to use the technology of CRISPR to modify the embryo for therapeutic purposes as long as issues of safety and effectiveness have not been resolved.

CRISPR, which was introduced in 2012, precisely cuts DNA but does not fix it. Natural DNA-repair mechanisms in the cell follow up by filling in the missing pieces.

CRISPR allows scientists to make extremely targeted edits to the genome of humans, animals and other organisms.

The news of the successful gene editing technique was first reported last week.

This progress has come over the attempts by the federal government to prevent it by not funding any research that leads to changes in the "germ line" - sperm, cells etc., that transmit genetic information. According to the scientists, their technique could potentially be applied to "thousands of inherited genetic disorders affecting millions of people worldwide". In the new study, researchers discarded the embryos a few days after fertilisation.

In a first-ever experiment, geneticists have successfully modified a human embryo to remove a mutation that causes a life-threatening heart condition. But the prospect of editing a child's DNA before they are born remains very controversial.

In fact, current legislation in the US prohibits the implantation of edited embryos. The phenomenon of "mosaicism" (simultaneous presence of genes in healthy and defective in embryo) could not be avoided, the researchers of the new study have been able to do.

Tweaking the genes of human embryos that could theoretically be brought to term and grown to adulthood is a feat that sounded like science fiction - until this week.

In a report this year, a panel of the National Academy of Sciences addressed the potential and the risks of germline engineering, concluding that basic research should proceed, closely watched.

Asked about critics of genetic manipulation, he said his work has nothing to do with the creation of "designer babies" through genetic manipulation to give the children traits desired by the parents.

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