Anorexia nervosa, bulimia nervosa, and binge-eating disorders are some of the common eating disorders. will experience at some point in their lives. Some of the recent studies on the genetic basis of anorexia nervosa have found a strong link between genetics and eating disorders.
Recently, a team of researchers has analysed the genome of tens of thousands of British people, and has discovered that genetic bases of these various eating disorders have similarities with those of other psychiatric disorders.
The team comprises researchers from the University of Geneva (UNIGE), the University Hospitals of Geneva (HUG), King’s College London, the University College London, the University of North Carolina (UNC) and The Icahn School of Medicine at Mount Sinai.
According to the study, published in the International Journal of Eating Disorders, eating disorders differ in their genetic association with anthropometric traits, like weight, waist circumference or body mass index.
Genetic predisposition to certain weight traits may be a distinctive feature of anorexia nervosa, bulimia nervosa or binge-eating disorder, says the study.
“Previous studies, which highlighted a genetic association between a high risk of anorexia nervosa and a low risk of obesity, have begun to lift the veil on certain aspects of how eating disorders develop that had been mostly neglected until then,” explains Nadia Micali, Professor at the Department of Psychiatry at UNIGE Faculty of Medicine and Head of the Division of child and adolescent psychiatry at the HUG, who directed this work. She continues, “However, the same work has not been done for the two other major eating disorders: bulimia nervosa and binge-eating disorder. The goal of our study was to understand similiarities and differences amongst all eating disorders in the role of genes governing body weight.”
To understand the similarities and differences between the genetic patterns of anorexia nervosa, bulimia nervosa and binge-eating disorder, the research team analysed the genomes of more than 20,000 people. These were taken from two large population-based studies conducted in the UK: the UK Biobank and the Avon Longitudinal Study of Parents and Children.
A genetic predisposition to a heavy weight versus a light weight may constitute a determining factor that pushes individuals with similar psychiatric genetic risk to different eating disorders.
“The metabolic and physical component would therefore direct the individual either towards anorexia nervosa or towards bulimia nervosa or binge-eating disorder,” analyses Nadia Micali. “Moreover, this study confirms a clear genetic relationship between binge-eating disorder and attention deficit hyperactivity disorder (ADHD), that was already clinically observed, which might be linked to greater impulsivity, which is shared by these disorders.”