Crispr: What is genome editing? All you need to know about Nobel-winning controversial technology

Two women — Emmanuelle Charpentier and Jennifer Doudna — were awarded the 2020 Nobel Prize for chemistry by the Nobel Committee on Wednesday.

The duo received the Nobel Prize in chemistry award for developing a method of genome editing, or gene editing, likened to “molecular scissors” that offers the promise of one day curing inherited diseases and even cancer.

Working on opposite sides of the Atlantic, Frenchwoman Emmanuelle Charpentier and American Jennifer A. Doudna developed the method known as Crispr/Cas9 that can be used to change the DNA of animals, plants and microorganisms with extremely high precision.

WHAT IS CRISPR AND GENOME EDITING?

Genome editing (also called gene editing) is a group of technologies that give scientists the ability to change an organism’s DNA. These technologies allow genetic material to be added, removed, or altered at particular locations in the genome.

Genome editing is of great interest in the prevention and treatment of human diseases. Currently, most research on genome editing is done to understand diseases using cells and animal models.

Gene editing is being explored in research on a wide variety of diseases, including single-gene disorders such as cystic fibrosis, haemophilia, and sickle cell disease. It also holds promise for the treatment and prevention of more complex diseases, such as cancer, heart disease, mental illness, and human immunodeficiency virus (HIV) infection.

Several approaches to genome editing have been developed. A recent one known as Crispr-Cas9 has generated a lot of excitement in the scientific community because it is faster, cheaper, more accurate, and more efficient than other existing genome editing methods.

DNA is a string with up to 6 billion coded instructions that tell a cell what to do. The beauty of Crispr/Cas9 is that it can not only snip DNA at the right spot but also repair the join so that errors do not creep in.

How the Crispr/Cas9 technology works. (Graphic: Reuters)

Crispr is repeating sequences of genetic code and serve as part of the bacterial immune system, defending against invading viruses.

CRISPR: WHAT ARE THE ETHICAL CONCERNS?

The path from discovery to prize has taken less than a decade — a relatively short period by Nobel standards.

And, although Crispr had widely been tipped to win the Chemistry Nobel prize, there has also been concern about possible misuse of the technology, for example, to create made-to-order ‘designer babies’.

“There is enormous power in this genetic tool, which affects us all,” said Claes Gustafsson, chair of the Nobel Committee for Chemistry. But he cautioned that the “enormous power of this technology means we have to use it with great care.”

Crispr has already raised serious ethical questions in the scientific community.

CRISPR: CONTROVERSIAL PAST

Most of the world became more aware of Crispr in 2018 when Chinese scientist Dr He Jiankui revealed he had helped make the world’s first gene-edited babies in an attempt to engineer resistance to future infection from the AIDS virus.

He Jiankui, working at the Southern University of Science and Technology (SUSTech) in Shenzhen, China, started a project to help people with fertility problems, specifically involving HIV-positive fathers and HIV-negative mothers. Using Crispr, the embryos were edited in an attempt to confer genetic resistance to HIV.

The clinical project was conducted secretly until 25 November 2018 when an expose by the MIT Technology Review revealed the study. Compelled by the situation, He immediately announced the birth of genome-edited babies in a series of five videos on YouTube the same day.

The first babies, known by their pseudonyms Lulu and Nana are twin girls born in October 2018. He’s work with Crispr was denounced worldwide as unsafe human experimentation because of the risk of causing unintended changes that can pass to future generations.

Amid widespread criticism, the Chinese government shut down He’s research project. He was later sentenced to three years in prison in December 2019 and was slapped with a fine of 3 million yuan. The Chinese authorities also brought in stringent rules governing gene-editing techniques such as Crispr.

For all the condemnation, however, it is important to note that many objections were not over the principle of human genetic modification as such, but rather over the way the experiment was carried out.

2020 Nobel winner Jennifer Doudna then said she felt “horrified” at hearing He’s talk, adding she felt deeply concerned for the people affected and questioned whether they really understood the procedure.

In September this year, an international panel of experts issued a report saying it’s still too soon to try to make genetically edited babies because the science isn’t advanced enough to ensure safety, but they mapped a pathway for any countries that want to consider it.

(with inputs from Associated Press)



Source link

Leave a comment