New Delhi: India has joined an elite group of six countries which have successfully decoded the human genome indigenously.
The discovery, which was announced by the Council of Scientific and Industrial Research (CSIR), will bring pharmaceutical companies a step closer to designing drugs accounting for the specific characteristics of the Indian physiology.
The US, the UK, China, Canada and South Korea are the five other countries to map the genetic code.
Every cell in the human body consists of strands of nucleic acid, called DNA (deoxyribonucleic acid), which are essentially made of permutations and combinations of four kinds of molecules, called bases.
The sequence of base pairs are a blueprint to the millions of proteins that are made up in the body and thus, the building blocks of every physiological process. These arrangements of base pairs that play some role in a protein’s fate and are usually consistent across individuals, are called genes.
A change in the base-pair sequence could mean certain proteins are not formed or some are processed in excess, causing mutations and thereby diseases.
The genome, as the bases, DNA and other hereditary molecules are collectively referred to, consists of around 3.1 billion base-pairs and 25,000 known genes. If all the DNA from every cell in the body were taken out and laid out end to end, it would stretch from the earth to sun 70 times and back.
Sequencing the entire genome essentially means photographing this chain of base pairs several times over, to accurately estimate an individual’s unique structure. The sequencing technique, Illumina-Solexa, used by CSIR, has been licensed from San Diego-based Illumina Inc.
Doing this fast enough requires enormous computing power and qualified manpower, adding to the cost. For sequencing the genome of the Indian, the Institute of Genomics and Integrative Biology (IGIB), which is part of CSIR, chose a 52-year-old male from Jharkhand, 167cm tall and weighing 52kg. The identity was not disclosed keeping with the ethical code laid down by the Indian Council for Medical Research.
Samir Brahmachari, CSIR head, said the sequencing was done in Delhi, between 25 September and 4 December, using a cluster of computers with one teraflop of processing power.
A teraflop refers to the processing speed of a computer and what IGIB employed is roughly 10,000 times more powerful than desktop computers available for Rs30,000 in India.
However, for scientists to be able to predict diseases, several more individuals would need to be sequenced.
“This is only the first step. A decade back, we couldn’t afford to do this and had to watch other scientists work at deciphering the human genome,” said Brahmachari. “Today we’ve basically bridged the technology gap. We can do this too, is our message.”
The next step would be to sequence 10 other Indians, said Rajesh Gokhle, director, IGIB, though he didn’t specify a time frame. China has an ongoing project to sequence the genomes of 100 citizens.
Experts say that the benefits of human genome sequencing will become apparent only after the cost of sequencing falls to $5,000 (Rs2.34 lakh) or less. It currently costs around $50,000 to commercially sequence the genome in the US.
“The good news is that just six years ago it cost a billion dollars to get a sequence done. Prices have fallen drastically since,” said Arjula Reddy, who co-chairs the genetic engineering approval comittee at the environment ministry. “When a lot of people sequence their genes, it will help scientists reliably predict disease probabilities.”
CSIR’s endeavour cost around $30,000, said Brahmachari, and that didn’t include the cost of infrastructure and manpower. Science minister Prithviraj Chavan likened CSIR’s achievement to Chandrayaan, India’s indigenously crafted moon mission. “It’s in the same league as Chandrayaan. When genetic tests become commonplace in the next few year, this will be a momentous day,” he said.