Breakthrough blood test finally confirms chronic fatigue syndrome

The condition, which causes long-term and often debilitating fatigue, affects millions of people around the world, including more than 400,000 people in the UK. Despite its prevalence, ME/CFS has remained poorly understood and difficult to diagnose.

This new test, which has shown 96 percent accuracy, offers renewed hope to patients who have struggled to be identified and get reliable answers. Researchers believe this discovery could also lead to a similar test to identify long-term coronavirus.

Validation of a disease that has long been denied

“ME/CFS is a serious and often disabling disease characterized by extreme fatigue that cannot be alleviated by rest,” explained lead researcher Professor Dmitry Pshezhitsky from Norwich Medical School at the University of East Anglia.

“We know that some patients have reported being ignored or even told that their disease is ‘all in their heads.’ With no definitive tests, many patients have remained undiagnosed or misdiagnosed for years.

“We wanted to see if we could develop a blood test to diagnose the condition – and we did!

“Our discovery offers the potential for a simple, accurate blood test to help confirm the diagnosis, which could lead to earlier support and more effective management.”

“Post-Covid syndrome, commonly referred to as long Covid, is an example of ME/CFS, where a similar set of symptoms is triggered by the Covid-19 virus, and not by other known causes such as glandular fever. So we hope our research will also help pave the way for a similar test to accurately diagnose long Covid.”

Using DNA folding to detect disease

To develop the test, the researchers used Oxford BioDynamics’ advanced EpiSwitch® 3D Genomics technology, which studies how DNA folds inside cells. The study analyzed blood samples from 47 people with ME/CFS and compared them with 61 healthy volunteers.

Each human cell contains about two meters of DNA, intricately folded in three dimensions. These folds are not random; They form deliberate patterns that help control how genes are activated or silenced, keeping the body functioning properly.

“Chronic fatigue syndrome is not a genetic disease you’re born with,” said Alexander Akulichev, chief scientific officer at Oxford BioDynamics. “That’s why using EpiSwitch ‘epigenetic’ markers – which can change over the course of a person’s life, unlike a fixed genetic code – was key to reaching this high level of precision.”

“The EpiSwitch platform behind this test, coupled with OBD’s extensive 3D genomic knowledge base, has proven to deliver practical, rapid, and widely accessible blood diagnostics.

“With this achievement, we are proud to enable a first-of-its-kind test that can address an unmet need for rapid and reliable diagnosis of a complex, difficult-to-identify disease.”

Proven technology behind the discovery

EpiSwitch technology has previously helped identify blood-based biomarkers for other complex conditions, including rapidly progressive amyotrophic lateral sclerosis (ALS), rheumatoid arthritis, and several cancers. It also supports the EpiSwitch PSE test for prostate cancer, which offers world-leading accuracy and is already in clinical use across the UK and US.

In the ME/CFS study, researchers found that the distinct genomic pattern is only present in affected individuals and absent in healthy participants. This work looked beyond the linear DNA sequences explored in the large DecodeME study, which was the most comprehensive genetic investigation of ME/CFS to date.⁽¹⁾

By examining the 3D structure of DNA, the UEA and Oxford BioDynamics team uncovered hundreds of additional biological differences, including five of the eight genomic regions previously identified by DecodeME. This deeper insight could enhance scientific understanding of the disease.

Uncover biological evidence for future treatments

The new analysis demonstrated exceptional accuracy, achieving a sensitivity of 92 percent (correctly identifying people with ME/CFS) and a specificity of 98 percent (correctly identifying people without it).

The researchers also observed signs of involvement of the immune system and inflammatory pathways, suggesting potential biological targets for future treatments. These results may help identify patients who are most likely to benefit from specific treatments.

Towards more accurate diagnosis and personalized care

“This is an important step forward,” said Professor Pszczytsky, from the University of East Anglia. “For the first time, we have a simple blood test that can reliably identify ME/CFS – which could change the way we diagnose and manage this complex disease.”

“In addition, understanding the biological pathways associated with ME/CFS opens the door to developing targeted therapies and identifying patients who may benefit most from specific treatments.

“We hope that the Episwitch® CFS test will become a vital tool in clinical settings, paving the way for more personalized and effective care.”

Notes

1. Genetics Discovery Team, et al (2025). Preliminary results from the DecodeME genome-wide association study of myalgic encephalomyelitis/chronic fatigue syndrome. medRxiv, preprint. https://doi.org/10.1101/2025.08.06.25333109

The research was led by the University of East Anglia and Oxford BioDynamics in collaboration with the London School of Hygiene & Tropical Medicine and Royal Cornwall Hospitals NHS Foundation Trust.

“Development and validation of blood-based diagnostic biomarkers for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) using EpiSwitch® 3D genomic regulatory immune genotyping” was published in the journal Journal of Translational Medicine.