New CRISPR Technique Repairs Genetic Mutations in Human Embryos

engineering careers  New CRISPR Technique Repairs Genetic Mutations in Human Embryos

Researchers have revealed a new CRISPR technique which might prevent humans from passing on a potentially life-threatening genetic disorder.

Marfan Syndrome is estimated to affect 1-in-5,000 people worldwide. The genetic disorder causes issues with the body’s connective tissue. Causing issues with everything from a person’s eyes, to their heart and some of these issues are fatal.

Marfan Syndrome is caused by a mutation in a persons FBN1 gene. A single piece of DNA code has the wrong ‘letter’. What should be a healthy “A” is a “G”.

At the moment a person with Marfan Syndrome has a 1-in-2 chance of passing it onto their child.

A team of researchers from China published a new study in Molecular Therapy this week that shows how CRISPR can to improve the odds of not passing on Marfan Syndrome.

In the past CRISPR was used to ‘cut-and-paste’ existing DNA. A genetic-engineer could target a specific piece of code and cut it out; replacing it with new code from elsewhere or allowing the strands of DNA to heal themselves. The problem was that these cuts produced odd and unwanted edits. Researchers even feared they could cause cancer.

Instead, the team used a technique instead uses ‘base editing’. This technique is not new; it has been around since 2016. Rather than cutting DNA out, a researcher can simply change one DNA ‘letter’ to another. For instance, they could swap an “A” to a “T”. This causes fewer unwanted edits than the old cut-and-paste approach

Up to now, this technique had never been tested on human DNA and it was not known if it would work.

The researchers decided to test their technique by taking aim at the DNA mutation that causes Marfan Syndrome by correcting the mutated FBN1 gene’s “G” back to an “A”.

The team tested their technique on 20 viable human embryos. The team were able to correct the mutation in 18 embryos; with 2 embryos showing an unintended change in the FBN1 gene (a C also changed to a T).

Overall the results are incredibly promising for the new technology. The team will now look to further refine their technique.

Read Correction of the Marfan Syndrome pathogenic FBN1 mutation by base editing in human cells and heterozygous embryos