In News:

• A researcher who claimed to have created the world’s first genetically-edited babies will face a Chinese police investigation, State media said, as authorities confirmed that a second woman fell pregnant during the experiment.

Explained:

• He Jiankui shocked the scientific community last year after announcing he had successfully altered the genes of twin girls born in November to prevent them from contracting HIV.
• The provincial government probe found He had “forged ethical review papers” and “deliberately evaded supervision
• He had “privately” organised a project team that included foreign staff and used “technology of uncertain safety and effectiveness” for illegal human embryo gene-editing,
• But such gene-editing work is banned in most countries, including China. Mr. He will be “dealt with seriously according to the law,” and his case will be “handed over to public security organs for handling
• He said the twins’ DNA was modified using CRISPR, a technique which allows scientists to remove and replace a strand with precision.

What is Gene 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. Several approaches to genome editing have been developed.
• A recent one is known as CRISPR-Cas9, which is short for clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9. The CRISPR-Cas9 system 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
• CRISPR-Cas9 was adapted from a naturally occurring genome editing system in bacteria. The bacteria capture snippets of DNA from invading viruses and use them to create DNA segments known as CRISPR arrays. The CRISPR arrays allow the bacteria to “remember” the viruses (or closely related ones).
• If the viruses attack again, the bacteria produce RNA segments from the CRISPR arrays to target the viruses’ DNA. The bacteria then use Cas9 or a similar enzyme to cut the DNA apart, which disables the virus.

Human Genome editing:

• 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. Scientists are still working to determine whether this approach is safe and effective for use in people.
• It is being explored in research on a wide variety of diseases, including single-gene disorders such as cystic fibrosis, hemophilia, 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.
• Ethical concerns arise when genome editing, using technologies such as CRISPR-Cas9, is used to alter human genomes. Most of the changes introduced with genome editing are limited to somatic cells, which are cells other than egg and sperm cells.
• These changes affect only certain tissues and are not passed from one generation to the next. However, changes made to genes in egg or sperm cells (germline cells) or in the genes of an embryo could be passed to future generations.
• Germline cell and embryo genome editing bring up a number of ethical challenges, including whether it would be permissible to use this technology to enhance normal human traits (such as height or intelligence). Based on concerns about ethics and safety, germline cell and embryo genome editing are currently illegal in many countries.