New Delhi: Sixteen years ago, on 26 June, US President Bill Clinton announced in the White House that a consortium of more than 1,000 researchers across six nations as part of the International Human Genome Sequencing Consortium had produced a rough draft of the human genome, calling it a “wondrous map". The announcement came nearly 50 years after James Watson and Francis Crick discovered the double helix structure of the human DNA.

In April 2003, the International Human Genome Sequencing Consortium finally announced the finished version of the human genome sequence. This version is available to the public, and shares all the information needed to do research using the whole genome.

Explaining the implications of the decoding of the human genome, Clinton had said, “genome science will have a real impact on all our lives—and even more, on the lives of our children. It will revolutionize the diagnosis, prevention and treatment of most, if not all, human diseases."

Treatment of human diseases—that is where we have arrived, 16 years later, after path breaking research from scientists across the world. After the human genome was decoded, the next big breakthrough which took the scientific world by a storm was CRISPR-Cas9.

Molecular biologists Jennifer Doudna at the University of California (UC), Berkeley, and Emmanuelle Charpentier, now at the Max Planck Institute for Infection Biology in Berlin, published their initial study on CRISPR in 2012. Feng Zhang from Broad Institute of MIT and Harvard published a paper on multiplex genome engineering using CRISPR/Cas systems in 2013. While a a dispute is still on as to who among these gets the patent for CRISPR, the research for the gene editing technology has gained much momentum in the past few years.

Here is a Mint explainer to understand how the technology is used to edit genes. CRISPR is a technology that allows medical scientists to change DNA with greater precision than was possible before. DNA can be repaired or even taken out using this technology.

Last year, Chinese scientists surprised the world by announcing they had used CRISPR to try and make changes to human embryos, in a bid to modify the genes which cause the blood disorder beta-thalassemia. While this research paper triggered a major furore regarding the safety of the procedure, in February, UK’s Human Fertilisation and Embryology Authority approved an application from Kathy Niakan of the Francis Crick Institute to renew her laboratory’s research licence to include gene editing of embryos.

The regulatory authority, however, highlighted that as with all embryos used in research, it is illegal to transfer them to a woman for treatment.

Another path-breaking announcement came from the US National Institutes of Health, when on 21 June it approved the first-in-human use of gene editing via CRISPR/Cas9 technology involving a proposal from University of Pennsylvania to use CRISPR–Cas9 to help enhance novel cancer therapies using patients’ T cells which are a type of immune cells. The trial will be funded by Sean Parker, best known as co-founder of Napster music website, through the Parker Institute for Cancer Immunotherapy, MIT Tech Review reported.

“This T cell immunotherapy protocol involves the use of CRISPR/Cas9 to edit two genes in T cells also modified to express T cell receptors targeting myeloma, melanoma, and sarcoma tumor cells," NIH noted in a blog.

Eighteen patients with various types of cancers will be part of the trial. Here is how Nature explained the three edits that will be made on the patients. “One edit will insert a gene for a protein engineered to detect cancer cells and instruct the T cells to target them, and a second edit will remove a natural T-cell protein that could interfere with this process. Finally, an edit will remove the gene for a protein that identifies the T cells as immune cells and prevent the cancer cells from disabling them. The researchers will then infuse the edited cells back into the patient."

There are questions regarding the safety of the procedure.

“While the application of new gene editing technologies in this field has great potential to improve human health, it is not without concerns," NIH noted in its blog on 16 June. But this approval could be a leap in this field of biomedicine.

More such trials are in the pipeline.

Editas Medicine, a Cambridge, Massachusetts-based company, has also said that it is likely to begin a trial in 2017 using CRISPR to treat a rare eye disease.