In News:

• CRISPR, a genome-editing technology developed 10 years ago, has begun to deliver on the near limitless potential that scientists say essential to improve the quality of human life.
• The technology enables a simple but remarkably efficient method of 'editing' the genetic codes of living organisms.

What’s in today’s article:

• About the CRISPR technology

The CRISPR technology:

• 
• The Clustered Regularly Inter-spaced Short Palindromic Repeats (CRISPR) is a technology (unveiled in 2012) that can be used to edit genes.
  • Genome editing, also known as genome engineering or gene editing, is a type of genetic engineering in which DNA (deoxyribonucleic acid) in the genome of a living organism is inserted, deleted, modified or replaced.
• Jennifer Doudna and Emmanuelle Charpentier, the technology's creators, were awarded the Nobel Prize in Chemistry in 2020.
• The technology mimics a natural defense mechanism used by some bacteria to protect itself from virus attacks.

How does it work?

• Under the CRISPR technology, the first task is to identify the particular sequence of genes that is the cause of the trouble.
• Once that is done, an RNA (ribonucleic acid) molecule is programmed to locate this sequence on the DNA strand, just like the ‘find’ or ‘search’ function on a computer.
• After this, a special protein called Cas9, which is often described as ‘genetic scissors’, is used to break the DNA strand at specific points and remove the bad sequence that causes disease or disorder.

Significance:

• There were ways to edit the genomes of some plants (particularly in the field of agriculture) and animals before the CRISPR method.
  • But it took years and cost hundreds of thousands of dollars. CRISPR has made it cheap and simple.
• The tools used to achieve this are not mechanical, but biochemical - specific protein and RNA molecules.
  • Hence, CRISPR technology is far more accurate and it does not involve the introduction of any new gene from the outside.

Potential it offers:

• A vast number of diseases and disorders are genetic in nature. These include sickle cell anaemia, colour blindness, cancer, diabetes, HIV and liver and heart diseases. Many of these are hereditary as well.
• The CRISPR technology opens up the possibility of finding a permanent cure to many of these diseases.
• This can also cure deformities arising out of abnormalities in gene sequences, like stunted or slow growth, speech disorders or inability to stand or walk.
• Over the last two and a half years, as the coronavirus pandemic ravaged the world, exposing humans' vulnerabilities to new diseases, CRISPR offers potential for permanent cures to some of the most difficult health disorders.

Some success stories:

• An American national (Victoria Gray), suffering from sickle cell anaemia, is now considered cured of the disease, using CRISPR technology.
• In India, scientists at CSIR’s Institute of Genomics and Integrative Biology have indigenously developed a CRISPR-based therapeutic solution for sickle cell anaemia, which is now being readied for clinical trials.
• In India, several research groups are working on CRISPR-based enhancements for various crops including rice and banana.

Challenges:

• The entire process is programmable and has remarkable efficiency, though chances of error are not entirely ruled out.
• The ethical concerns:
  • Because CRISPR has the potential to cause dramatic changes in an individual, scientists have warned of the technology's misuse.
  • In 2018, a Chinese researcher revealed that he had altered the genes of a human embryo in order to prevent HIV infection. This was the first documented case of a 'designer baby,' and it sparked widespread concern among scientists.
    • Preventive interventions to obtain special traits are not something scientists currently want to use the technology for.
• Changes in genetic sequences caused by therapeutic interventions remain with the individual and are not passed onto offspring.