Somatic genetic variants

August 31, 2023

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

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