A landmark study led by King’s College London, University of North Carolina and Stanford researchers identifies the first genetic variant for anorexia nervosa and reveals that there may also be metabolic underpinnings to this potentially deadly illness.
‘This is the largest and most statistically powerful genetic study of anorexia nervosa ever conducted. We have analysed over 10 million genetic variations across the genome in 3,495 individuals with anorexia nervosa and 10,982 unaffected individuals’, said lead geneticist Dr Gerome Breen, of King’s College London’s Institute of Psychiatry, Psychology & Neuroscience.
‘We identified one genetic variant associated with anorexia nervosa on chromosome 12, in a region previously shown to be associated with type 1 diabetes and autoimmune disorders,’ said lead investigator, Cynthia Bulik, PhD, FAED, founding director of the UNC Center of Excellence for Eating Disorders and a professor at Karolinska Institutet in Stockholm, Sweden.
‘We also calculated genetic correlations – the extent to which various traits and disorders are caused by the same genes,’ said Bulik. ‘Anorexia nervosa was significantly genetically correlated with neuroticism and schizophrenia, supporting the idea that anorexia is indeed a psychiatric illness.
‘But, unexpectedly, we also found strong genetic correlations with various metabolic features including body composition (BMI) and insulin-glucose metabolism. This finding encourages us to look more deeply at how metabolic factors increase the risk for anorexia nervosa’, Bulik said.
Dr Breen added: ‘In the era of team science, we brought together over 220 scientists and clinicians to achieve this large sample size. This shows the power of large scale genomics in large samples – without this study we would never have been able to discover that anorexia has both psychiatric and metabolic genetic roots.’
This study was conducted by the Psychiatric Genetics Consortium Eating Disorders Working Group – an international collaboration of researchers at multiple institutions worldwide.
Laramie Duncan, PhD, of Stanford University, who served as lead analyst on the project, said: ‘These results highlight the general mechanisms that are important in anorexia nervosa and our consortium will be carrying further, larger studies to characterise the many specific genes and biological pathways that are involved.’
The researchers are continuing to increase sample sizes and see this as the beginning of genomic discovery in anorexia nervosa. Viewing anorexia nervosa as both a psychiatric and metabolic condition could ignite interest in developing or repurposing medications for its treatment where currently none exist.
Institutions that participated in this research include the University of North Carolina at Chapel Hill; Karolinska Institutet; King’s College London; Stanford University; the Broad Institute of MIT and Harvard University; Massachusetts General Hospital; Charité-Universtätsmedizin Berlin; the Department of Child and Adolescent Psychiatry at the University Hospital Essen (or University of Duisburg-Essen).
Source: King’s College London