March 21 2018

Scientists successfully 'edit' embryo genes to prevent inherited disease

March 21 2018, 12:42 | Irvin Gilbert

Scientists successfully 'edit' embryo genes to prevent inherited disease

Scientists successfully 'edit' embryo genes to prevent inherited disease

The UK received a licence in 2016 to carry out CRISPR on human embryos for research into early development.

Thousands of inherited diseases such as Huntington's Disease and Cystic Fibrosis could eventually be nipped in the bud after a major breakthrough in gene editing.

In the current study USA researchers targeted a faulty gene, MYBPC3, that causes hypertrophic cardiomyopathy. The National Institutes of Health has also barred spending funds on embryonic research.

An account of the research, complete with photos of the multiplying cells, was published in the prestigious British journal "Nature". "That's still true, but now it looks like it's going to be done safely soon". "So there is still a long road ahead, particularly if you want to do it in a regulatory way". As a result, only 28% of the resulting embryos carried genes for hypertrophic cardiomyopathy.

The efficiency of gene editing in the Nature paper is exciting, says stem-cell biologist George Daley of Boston Children's Hospital in MA. It's well known among cardiologists for killing young athletes.

Scientists estimate that more than 10,000 human diseases may result from mutations to a single gene occurring in all cells of the body, according to the World Health Organization. The researchers simultaneously injected CRISPR-Cas9 components with the sperm to fix the mutation and produce embryos with two healthy copies of the gene. He then introduced CRISPR to splice out the mutated gene in more than 50 embryos just after the sperm fertilized the eggs, when the embryos were still just one cell.

This latest paper is not the first time human embryos have been genetically modified, and is one of many examples of CRISPR being successfully applied to remove a target gene.

But in three previous Chinese studies, this has proven easier said than done. "Then, DNA fix of the embryos was assessed". The study that was conducted in United States 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. Some countries, especially in Europe, ban germline research. Typically, researchers wishing to edit a genome will insert DNA encoding CRISPR components into cells, and then rely on the cells' machinery to generate the necessary proteins and RNA. "I think it will be up to them to decide where to draw the line".

Pieces of RNA are engineered to be a guide that homes in on the targeted stretch of genetic material.

But the researchers say that method is expensive and hard on a mother. That condition, which strikes about one in every 500 people worldwide, can cause sudden heart failure. Her boy is a carrier, but her girl, Sofia, has the disease. "It is far too early to extrapolate this into any clinical application", Middleton said.

She was so moved by early reports of the research that she called OHSU last week to thank the researchers.

"I feel that the practical thing to do is deal with the diseases people have, not with the disease they may have", he said.

The work at OHSU was paid for by the hospital.

"This is the first that has been demonstrated as safe and working", said Belmonte, a professor at the Salk Institute for Biological Studies' gene expression laboratory in La Jolla, California.

The new CRISPR technique could be used to increase the number of viable embryos for implantation, said the team, thus reducing the number of eggs that have to be invasively harvested. When that was done, 42 out of 58 edited embryos were found to be free of the hypertrophic cardiomyopathy mutation.

Scientists not involved in the project hailed it a landmark in genetics. "It needs to be regulated very closely and needs to be done in a very responsible way". He is director of the Utah Center of Excellence in Ethical, Legal, Social Implications Research (UCEER) and professor of pediatrics and medical ethics at the University of Utah School of Medicine. They effectively corrected the problematic sperm gene 72 per cent of the time, and even in those instances where they did not correct it, the problematic gene was still deleted. Mitalipov would like 100 percent.

He's talking about "designer babies", in which genes are altered to give parents whatever traits they'd like. "This brings it closer to clinic, but there's still a lot of work to do".

"This technology, independent of the embryos that are there, it would go on and correct all of them".

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