GENOMIC SEQUENCING

GENOMIC SEQUENCING

Subject : Science & tech

Context : Of the 14 Covid-19 samples processed by the National Centre for Disease Control (NCDC) to check genome sequencing, eight have tested positive for the new variant found in the UK, informed the Ministry of Health and Family Welfare.

Concept :

• Genome: It is an organism’s complete set of DNA, including all of its genes.
• Each genome contains all of the information needed to build and maintain that organism. In humans, a copy of the entire genome—more than 3 billion DNA base pairs—is contained in all cells that have a nucleus.

Genome sequencing:

• It is figuring out the order of DNA nucleotides, or bases, in a genome—the order of As, Cs, Gs, and Ts that make up an organism’s DNA. The human genome is made up of over 3 billion of these genetic letters.
• Sequencing the genome doesn’t immediately lay open the genetic information of an entire species. Even with a rough draft of the human genome sequence in hand, much work remains to be done. Scientists still have to translate those strings of letters into an understanding of how the genome works.

Methodology

• Genomes will be sequenced based on a blood sample.
• Every person whose genomes are sequenced will be given a report. The participants would be told if they carry gene variants that make them less responsive to certain classes of medicines.
• For instance, having a certain gene makes some people less responsive to clopidogrel, a key drug that prevents strokes and heart attack.
• The sequencing to be done at the CSIR-Institute of Genomics and Integrative Biology (IGIB) and the Centre for Cellular and Molecular Biology (CCMB).

Applications

• Determining genetic traits and gene-disease link: Ever since the human genome was first sequenced in 2003, it opened a fresh perspective on the link between disease and the unique genetic make-up of each individual.
• Nearly 10,000 diseases — including cystic fibrosis, thalassemia — are known to be the result of a single gene malfunctioning.
• While genes may render some insensitive to certain drugs, genome sequencing has shown that cancer too can be understood from the viewpoint of genetics, rather than being seen as a disease of certain organs.
• Mapping population diversity: Participants of genome-sample collections represent diversity of the country’s population.
• It will help us to compare causes of diseases across other countries. For instance, in developed countries diarrhoeal infections are rarer than in India. It will help understanding of role of genes in this and can track health changes over long periods.