• With the recent explosion in the amount of data available, scientists have shed new light on somatic genetic variants.

HOW ARE THEY FORMED?

• The human genome has 23 pairs of chromosomes, one inherited from each of our parents.
• The genome is the blueprint of our genetic makeup.
• After fertilisation, the combined single cell, with the 23 chromosomes, starts to divide, copying the genetic material over and over to nearly a trillion cells – which make up the human body.
• As the cells divide, the DNA is copied with extremely high accuracy thanks to proteins that proofread and correct errors in the DNA.
• But despite this mechanism, there is still an error rate of 0.64-0.78 mutations per billion base pairs per division.
• The number and effect of these errors vary significantly, depending on the stage of development or the point in the life-cycle at which they occur.
• An error that occurs in the DNA after birth but during development is called a somatic genetic mutation.

Turnover means the replacement of old cells with new ones. Germline mutations are inherited from parents and are present in every cell of an individual’s body.

• Their occurrence is driven by the repeated ‘copy-pasting’ of the genome – which means there will be more somatic genetic mutations the older an individual is and the higher the turnover of the tissue.

IMPACTS

• Sometimes, a somatic genetic mutation can render a cell fitter than others, which lead to the formation of tumours. So these mutations are called driver mutations.
• Many genetic conditions arise from somatic genetic variants.
• Somatic genetic variants are important for a number of normal physiological processes like immune system

USE OF THIS INFORMATION-

• Can help with early detection, diagnosis, and prognosis of cancer.
• Detection of development of genetic diseases.
• Precision medicine