Computation Analysis of Indian Genes | 28 Oct 2020

Why in News

Recently, the results from the computation analysis of the 1029 sequenced genomes from India were published in the scientific journal, Nucleic Acid Research.

Key Points

  • The analysis has found that out of 55,898,122 single nucleotide variants in India 18,016,257 (32.23%) variants are unique and found only in the samples sequenced from India.
    • This emphasizes the need for an India centric population genomic initiative.
  • The analysis was carried out by CSIR constituent labs, Institute of Genomics and Integrative Biology (IGIB), Delhi and Centre for Cellular and Molecular Biology (CCMB), Hyderabad.

IndiGenomes Resource Database

  • It encompasses the genomic data from over 1000 whole genome sequences sequenced from across India as part of the IndiGen programme and represents diverse geographies and ethnicities.
    • The IndiGen Programme was launched in April 2019, under which genome sequencing of 1029 self-declared healthy Indians drawn from across the country has been completed.
    • Its objective was to enable genetic epidemiology and develop public health technologies applications using population genome data.
  • The resource provides access to over 55 million genetic variants representing the contemporary Indian population with an objective to classify variants involved in mendelian disorders and improve precision medicine outcomes.
    • Mendelian disorder is a type of genetic disorder, resulting due to alterations in a gene or due to abnormalities in the genome.
  • It enables the identification of markers for carrier screening, variations causing genetic diseases, prevention of adverse events and provides better diagnosis and optimal therapy through mining data.
  • This resource can provide useful insights for clinicians and researchers in comprehending genetics not only at the population level but at the individual level.

Background

  • Despite having this rich genetic diversity, India has been under-represented in global genome studies. Further, the population architecture of India has resulted in high prevalence of recessive alleles.
  • In the absence of large-scale whole genome studies from India, the population-specific genetic variants are not adequately captured and catalogued in global medical literature.
  • In order to fill the gap of whole genome sequences from different populations in India, CSIR initiated the IndiGen Programme.

Genome

  • A genome is all the genetic matter in an organism. It is defined as an organism’s complete set of Deoxyribose Nucleic Acid (DNA), including all of its genes.
    • Every organism’s genetic code is contained in its DNA, the building blocks of life.
  • Each genome contains all of the information needed to build and maintain that organism.
  • In humans, a copy of the entire genome contains more than 3 billion DNA base pairs.

Genome sequencing

  • Genome sequencing is figuring out the order of DNA nucleotides, or bases, in a genome—the order of Adenine, Cytosine, Guanines, and Thymine that make up an organism's DNA.
  • Application:
    • Genome sequencing can play a crucial role for new advancements in medical science (like predictive diagnosis and precision medicine, genomic information) and in disease management.
    • Through genome sequencing methodology, researchers and clinicians can easily detect the disease related to genetic disorder.
  • Importance of Genome Sequencing:
    • The study of entire genome sequences will help understand how the genome as a whole works—how genes work together to direct the growth, development and maintenance of an entire organism.
    • The genes account for less than 25% of the DNA in the genome, and so knowing the entire genome sequence will help scientists study the parts of the genome outside the genes.

Source: PIB