Anorexia nervosa, bulimia nervosa and eating disorders are the three main eating disorders experienced by 4 out of 10 people living in western Europe at some point in their lives. In recent years, studies on the genetic basis of anorexia nervosa have highlighted the presence of predictive genetic markers, which are shared by other psychiatric disorders. Genome analysis of tens of thousands of British people, a team from the University of Geneva (UNIGE), University Hospitals of Geneva (HUG), King’s College London, University College London, University of North Carolina (UNC) and The School of Medicine Icahn at Mount Sinai has built on these initial findings by discovering similarities between the genetic underpinnings of these various eating disorders, and other mental disorders. Eating disorders vary in their genetic connection to anthropometric indicators, such as weight, waist circumference or body index. Thus, genetic predisposition to specific stress symptoms may be a characteristic feature of anorexia nervosa, bulimia nervosa or binge eating disorder. The study is published in the International Journal of Eating Disorders.
“Previous studies, which have identified a genetic link between high risk of anorexia nervosa and low risk of obesity, have begun to raise awareness of some aspects of how eating disorders develop that were largely neglected. part until then “, explains Nadia Micali, Professor in the Department of Psychology at UNIGE Faculty of Science and Head of the Department of Child and Adolescent Psychology at the HUG, who led this work. She continues,” But , the same work was not performed for the other two major eating disorders: bulimia nervosa and binge eating disorder. The aim of our study was to understand similiarites and differences among all eating disorders in the role of genes in regulating body weight. “
The genome of more than 20,000 people was studied
To understand the similarities and differences between the genetic patterns of anorexia nervosa, bulimia nervosa and binge eating disorder, the research team analyzed the genomes of more than 20,000 individuals. These were drawn from two large population-based studies conducted in the UK: Biobank UK and the Avon Longitudinal Study of Parents and Children.
The first author, Dr Christopher Hübel, of King’s College London, said: “We were able to access volunteer DNA, their basic health data (weight, age, etc.) and responses to health questionnaires, giving including psychiatric disorders and their history of eating disorders. We are grateful for this accessibility because we were able to perform multitasking analyzes and work out more than 250 polygenic scores per person. Each polygenic score takes into account the risk genes involved in a particular draw, such as depression, for example. We measured polygenic scores for psychiatric disorders, such as schizophrenia and obsessive-compulsive disorder, and metabolic and physical symptoms, including insulin sensitivity, obesity and high BMI. the higher the score, the greater the genetic risk, regardless of whether it is blue eyes or the development of a specific disease.
The research team then examined the associations between the polygenic scores of these volunteers (representing a genetic predisposition to mental disorders, metabolic and physical symptoms) and eating disorders.
A combination of genetic risk management of mental and physical stress
The study shows that while there are significant genetic similarities between anorexia nervosa, bulimia nervosa and binge eating disorder, there are also significant differences.
Nadia Micali details these findings: “The similarities lie in relation to psychiatric risks: anorexia nervosa, bulimia nervosa and binge eating disorder share a genetic risk with some psychiatric disorders, especially for schizophrenia and depression, thus confirming the strong psychological component of these. diseases. However, the major genetic differences are related to the management of body weight, which is the opposite of anorexia on the one hand, and bulimia nervosa and binge eating disorder on the other, with the one about end associated with high genetic risk of obesity, and high BMI. ”
A genetic shift to heavy weight versus light weight could be an important trait that pushes people with a genetic-minded genetic risk similar to various eating disorders.
“Thus the metabolic and physical part would lead the individual to anorexia nervosa or bulimia nervosa or binge eating disorder”, analyzes Nadia Micali. Furthermore, this study confirms a clear genetic relationship between binge eating disorder and attention deficit hyperactivity disorder (ADHD), which has already been clinically observed, which may be linked to greater impulsivity, which is shared by these disorders. ” The role of genetic patterns in the management of body weight identified in this study provides a better understanding of the genetic basis of eating disorders, and how they differ in genetic markers despite their similarity. . This work could lead to a better understanding of the development of eating disorders.
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This study was made possible with the support of funding from the United States National Institute of Mental Health and funding from the Maudsley Biomedical Research Center (BRC) of the National Institute for Health Research (NIHR).
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