Key genetic differences found in people with chronic fatigue syndrome

Genetic factors that could contribute to the risk of people to develop chronic fatigue syndrome (CFS), also known as the myalgic encephalomyelitis (ME), have been identified in a large study. Scientists have linked eight regions of the human genome on condition, based on DNA samples of more than 15,000 people who have it.

“Our study provides the first solid evidence of genetic contributions to me,” said Sonya Chowdhury during charitable action for me in the United Kingdom.

In the long term, the results could contribute to the development of new diagnostic and treatments for Me / CFS, which has been recognized for decades and is marked mainly by post-exertional discomfort, a severe and debilitating response to a even light effort.

But already, the results provide “validity and credibility” to people with the disease, explains Chowdhury. “Many people have experienced comments like” me is not real, “she says. “They went to doctors and were disbelieved and said it was not a real illness.”

“It will be enormous for the population of patients,” explains Andy Deveraux-Cooke, co-founder of The Science for Me Forum, which has been the condition for 45 years.

The study, called a decodem, compared DNA samples of just over 15,500 people with me / CFS and nearly 260,000 without him, which were all in the United Kingdom and European ancestry.

“We found eight genetic signals,” explains Chris Ponting at the University of Edinburgh in the United Kingdom. The eight regions of the genome involved seem significantly different in people with me / CFS, which indicates that genetic variants contribute to the risk of developing it. The University of Edinburgh announced the results in a press briefing, but they have not yet been published in a newspaper or on a pre-print server.

In these eight regions, the team identified 43 genes coding for proteins, including 29 seemed particularly promising. “When we rummage in these eight different genetic signals, we find genes linked to both the immune system and the nervous system,” explains Ponting. “Overall, the activities of the genes of these signals are enriched in brain tissues. They are more likely to be active in the brain than elsewhere, pointing towards an involvement of the nervous system. ”

Researchers also identified a gene linked to the immune system called Rabgap1l As a probable contributor to me / CFS risk. This corresponds to the testimony of most people with the condition, who say that an initial infection, which often seemed light, preceded the appearance of their symptoms.

“My thought has always been that there is something different in the immune system in people with me / CFS,” explains Jackie Cliff at the Brunel University of London, who adds that the study is “a good leap forward in research on me / CFS”.

The work has found no difference in the genetic risk between men and women, even if Me / CFS is much more common in women. However, the team has not yet analyzed the sex chromosomes X and Y.

The next step is to study the eight regions of the genome that have been highlighted in more detail, to try to understand how genetic alterations are translated into molecular and cellular process in people with and without CFS. This could one day lead to diagnostic tests and drug treatments that target the basic mechanisms of the condition. However, this will only happen if research donors support it. “There is an absolute shortage of financing,” explains Cliff.

The damage caused by Me / CFS is considerable, with around 67 million people affected by it worldwide. A 2017 Think Tank 20Health report estimated that it costs the British economy 3.3 billion pounds sterling per year in health care and lost productivity. “It is a forgotten and abandoned disease and, therefore, which deserves a lot of attention and investment of people,” explains Ponting.