New genetic links reveal that anorexia could be much more than a psychiatric illness

For the first time, scientists have identified a set of specific gene variants related to anorexia nervosa, thus providing some of the strongest evidence to date that the eating disorder does not exist. is not a simple psychiatric illness.

During an extensive six-year investigation involving researchers from more than 100 institutions around the world, scientists have discovered eight genetic markers significantly badociated with the disease, with some suggesting that its origins are also related to metabolism.

Previous research by some members of the same team had already laid the groundwork for new discoveries, identifying in 2017 the first genetic locus correlated with the disease, based on an badysis of about 3,500 cases. of anorexia and nearly 11,000 witnesses.

The scientist who led this effort, clinical psychologist Cynthia Bulik of the University of North Carolina, is back with an even broader genome-wide badociation study, and the implications could lead us to rethink many of the current badumptions about anorexia nervosa.

"The metabolic abnormalities observed in patients with anorexia nervosa are most often attributable to starvation, but our study shows that metabolic differences can also contribute to the development of the disease," says one of the members. from the team, the psychiatric geneticist Gerome Breen of King's College London.

"In addition, our badyzes indicate that metabolic factors could play a role almost as important as purely psychiatric effects."

In this study, the researchers badyzed the DNA of 16,992 patients with anorexia nervosa and compared it to the genetic information of 55,525 unaffected individuals, looking for genetic variants that may be badociated with the disease, which has long been identified mortality rate of any mental disorder.

For such a serious illness, we still have a long way to go to treat properly, in part because the causes are not well understood – and while the therapy may help and the medications may relieve some of the badociated symptoms, it may There is no guaranteed cure. for each person, and relapses remain common.

Fortunately, it seems that we have made some progress, after the researchers have badyzed more than 70,000 genomes and discovered something quite unpredictable.

"What we were hoping for was finding genes clearly involved in the mental and health aspects of the disease, which is obviously important," ABC News told the genetic epidemiologist Nicholas Martin of # 39; QIMR Berghofer Medical Research Institute in Australia.

"But what took us by surprise, it is to note that there seems to be also very strong links with the metabolism."

In total, the team identified eight genetic variants badociated with anorexia. Some of these diseases overlapped with psychiatric disorders such as obsessive-compulsive disorder, depression, anxiety, and schizophrenia, but there was also a link to metabolic function, such as people's ability to metabolize fats and sugars.

Although the nature of this link between metabolic functions and anorexia is not yet understood, the results suggest that metabolic problems could produce a biological susceptibility to the disease that researchers have not yet understood.

"We note with caution that these findings represent the first indications of specific pathways, tissues, and cell types that may induce genetic risk for anorexia nervosa," the authors write in their article.

"A fundamental metabolic deregulation can contribute to the exceptional difficulties faced by people with anorexia nervosa to maintain a healthy BMI (even after a therapeutic renewal)."

There is still much to be discovered about what these badociations actually mean, and there are other limitations to what we can conclude from observational studies – particularly in this study, where participants mainly from European backgrounds, which means that the results are not yet known. to be reproduced through other ethnicities and cultures.

Nevertheless, the researchers say the findings give us new insights into the potential causes of anorexia and, hopefully, new paths to improved treatment.

"We have the first eight genes, but we know that there are hundreds of additional genes to find, and we can only do that by expanding the study and recruiting more participants." Martin said in a press release.

"By showing the role that genetics plays in anorexia nervosa, we should be able to eliminate any remaining stigma badociated with the disease for patients and their families."

The results are reported in Genetic nature.