Cell-free DNA promises to transform how we find diseases

Source: The post is based on the article “Cell-free DNA promises to transform how we find diseases”  published in The Hindu on 31st July 2023.

What is the News?

Scientists have been aware of cell-free DNA (cfDNA) since 1948.But only in the last two decades, since genome sequencing started to become more accessible, have they really figured out what to do with that knowledge.

What is cell-free DNA (cfDNA)?

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.

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).

How are cell-free DNA (cfDNA) produced?

Cell-free DNA can be produced and released from a cell in various situations, such as during cell death when nucleic acids degrade. 

The degradation is influenced by multiple processes causing variations in the amount, size, and origin of cfDNA. 

The release of cfDNA could occur together with a variety of processes, including those required for normal development, those related to the development of certain cancers and those associated with several other diseases. 

What are the applications of cell-free DNA (cfDNA)?

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 also useful in understanding why a body is rejecting a transplanted organ.

Further, cfDNA could also be used as a biomarker for neurological disorders like Alzheimer’s disease, neuronal tumours, stroke, traumatic brain injury.