Cell-free DNA

August 1, 2023

In the human body, most of the DNA in a genome is neatly packed inside cells with the help of specific proteins, protecting it from being degraded.
However, in a variety of scenarios, some fragments of DNA are ‘released’ from their containers and are present outside the cell, in body fluids.
- These small fragments of nucleic acids are widely known as cell-free DNA (cfDNA).
cfDNA can be generated and released from a cell in a number of possible situations, including when a cell is dying and the nucleic acids become degraded.
Scientists have been aware of such degraded fragments of nucleic acids in body fluids since 1948.
But only in the last two decades or so, since genome sequencing technologies started to become more accessible, have they really figured out what to do with that knowledge.
Applications
- By far, one of the most widely used applications of cfDNA has been in screening foetuses for specific chromosomal abnormalities, an application known as non-invasive prenatal testing.
- Another emerging application of cfDNA is in the early detection, diagnosis, and treatment of cancers.
- It is useful in understanding why a body is rejecting a transplanted organ.
- This could be used as a biomarker for neurological disorders like Alzheimer’s disease, neuronal tumours, stroke, traumatic brain injury.