How will genome sequencing lead to customised treatments for Indians?

The samples were taken from 99 ethnic groups spanning 20 centres.

India recently achieved a significant milestone with researchers sequencing 10,000 healthy genomes from diverse communities across the country. The samples were taken from 99 ethnic groups spanning 20 centres.

Union Minister for science and technology, Jitendra Singh, described the event as a “watershed moment” which will lead to genetic-based development and improve India’s public healthcare system. “Genome study or sequencing is going to determine the future healthcare strategies across the world, both therapeutically and prophylactically,” the minister said while announcing the completion of the genome sequencing at an event in New Delhi recently.

The USA, UK and China are the only countries that have programmes to sequence at least 1,00,000 of their genomes. India’s 1.3 billion population consists of more than 4,600 population groups.

What is genome sequencing?

The human genome is the set of deoxyribonucleic acid (DNA) in the nucleus of every cell of each human body. The set has the complete genetic information responsible for the development and functioning of the organism. The human genome is the complete map of all 23 large DNA sequences that encode human beings.

The DNA consists of a double-stranded molecule built up by adenine (A), cytosine (C), guanine (G) and thymine (T). Every base on one strand is paired with a complementary base on the other strand (A with T and C with G). The genome reportedly is made up of approximately 3.05 billion such base pairs. The process of deciphering the order of base pairs and decoding the genetic fingerprint of a human is called genome sequencing.

Why is it important?

Genome sequencing is used to evaluate rare disorders, preconditions and even cancer from the viewpoint of genetics. Whole-genome sequencing enables us to read a person's individual genome. According to reports, the analysis of 5,750 genomes has helped in identifying 135 million genetic variants in India.

“For the common people, genome sequencing will help in identifying the genetic cause for various diseases. One can estimate the frequency of deleterious mutations and also help in improving diagnostic methods in terms of time and cost. It will also provide appropriate pre-natal and pre-marital counselling to avoid mutations passing to the next generation,” said Y Narahari, one of the joint coordinators of Genome India project.

What is India’s 10,000 genome project?

The project was launched in 2020. About 20 institutions across India are involved with the Indian Institute of Science (IISc), Bengaluru and the Centre for Cellular and Molecular Biology, Hyderabad being the lead institutions for the project. Beyond the sequencing of the genome, the project has paved the way for creation of a biobank housing 20,000 blood samples at the Centre for Brain Research, coupled with data archiving at the Indian Biological Data Centre. Creating a database means that researchers anywhere can learn about genetic variants that are unique to India's population groups and use that to customise treatment.

How did genome sequencing help during pandemic?

At the beginning of the Covid-19 outbreak in 2020, genomic sequencing became one of the first steps to track emerging variants. The purpose of genome sequencing was to understand the role of certain mutations in increasing the virus’s infectivity. India also put in place a sequencing framework and the Indian SARS-COV-2 Genomics Consortia, a consortium of labs across the country, was tasked with scanning coronavirus samples. In the later stage of the pandemic in 2022, sequencing helped in targeted efforts at ebbing infections.