Central Idea

Researchers worldwide are increasingly using Cell-free DNA (cfDNA) as a valuable tool to better comprehend human diseases, improve diagnosis, monitoring, and prognosis.

What is Cell-free DNA?

CfDNA refers to small fragments of nucleic acids that are released from cells and found outside the cell in body fluids.
Its discovery dates back to the late 1940s when it was first observed in the blood of pregnant women.
cfDNA can be generated and released from cells in various situations, such as cell death and other physiological processes.
The release of cfDNA is associated with several disease processes, including autoimmune diseases like systemic lupus erythematosus.

Cell-free DNA	Normal DNA
Found in the bloodstream and other bodily fluids	Found within the cell nucleus or mitochondria
Released from dying or dead cells into the circulation	Remains within the cell’s nucleus or mitochondria
Exists in a fragmented form	Exists as an intact double-stranded helix
Can be isolated and analyzed from blood samples	Requires cell extraction and purification for analysis
Provides valuable genetic information for personalized medicine	Forms the basis of genetic inheritance and traits
Valuable in infectious disease diagnosis and monitoring	Not used for infectious disease diagnosis
Used in forensics for DNA profiling and crime investigations	Not typically used in forensics

Non-Invasive Prenatal Testing (NIPT)	Detect genetic abnormalities in foetuses Screening for Down syndrome, Edwards syndrome, and Patau syndrome
Cancer Screening and Monitoring	Identify genetic mutations in tumour cells Determine cancer type Monitor treatment response and disease progression
Transplant Rejection Monitoring	Monitor immune response after organ transplantation Early detection of organ rejection
Infectious Disease Diagnosis	Identify viruses and bacteria in the bloodstream Aid in diagnosing infections and guiding treatment
Personalized Medicine	Provide genetic information for tailored treatment plans Enable precision medicine based on individual genetic profile
Tracking Tumour Mutations	Monitor drug-resistant mutations in cancer patients for treatment adjustments

GEMINI Test: Researchers at Johns Hopkins Kimmel Cancer Centre developed a new test called ‘GEMINI’ that uses cfDNA for early cancer detection. By analyzing genetic mutations and using machine learning, they achieved over 90% accuracy in detecting lung cancer, even in early-stage cases.
Potential Impact: Early detection of cancers using cfDNA could significantly improve patient outcomes and survival rates.