Australian volunteers wanted for eating disorders study

Australian researchers are calling for more than 3500 volunteers — with first-hand experience of an eating disorder — to enrol in a study investigating genetic predisposition to three complex eating disorders.

Reported to be the world’s largest genetic investigation into eating disorders, the Eating Disorders Genetics Initiative (EDGI) aims to identify the hundreds of genes that influence a person’s risk of developing anorexia nervosa, bulimia nervosa and binge-eating disorder, to improve treatment and, ultimately, save lives.

An EDGI investigator article published today in MJA Insight¹ outlines the substantial advances made in a recent international collaborative study — Anorexia Nervosa Genetics Initiative (ANGI) — which reveals the psychiatric and metabolic origins to anorexia nervosa and eight genetic variants associated with the illness.² EDGI will further the advances made in this study, in order to revolutionise future research into the causes, treatment and prevention of eating disorders.

“Identifying the genes that predispose individuals to the development of an eating disorder is like assembling a jigsaw puzzle,” said article co-author, EDGI Principal Investigator, Distinguished Professor of Eating Disorders, Department of Psychiatry, School of Medicine, University of North Carolina, Professor Cynthia Bulik.

“The more pieces we have on the table, the clearer the biological picture of the underlying causes of the disorder, and the better the chance of developing new and improved, personalised interventions and treatments.

“Genetically, our preliminary ANGI research — which compared 17,000 participants with more than 55,000 controls from 17 countries — revealed both psychiatric and metabolic origins to anorexia nervosa, explaining why people living with the disorder struggle to gain weight, despite their best efforts. The study also identified eight genetic variants significantly associated with anorexia nervosa.²

“Our new study, EDGI, offers us a unique opportunity to further investigate the complex interplay of genetic and environmental factors that contribute to eating disorders, in order to improve treatments and save lives,” Professor Bulik said.

Eating disorders are complex mental illnesses that can lead to severe and permanent physical complications and even death.³ Eating disorders have one of the highest mortality rates of any mental illness.^4-6 While family and twin studies have confirmed eating disorders run in families, only a handful of the responsible genes have been identified to date, leaving hundreds more to be found.

Australian Lead Investigator, Geneticist and Head of the Genetic Epidemiology Research Group at QIMR Berghofer Medical Research Institute, Professor Nick Martin is seeking more than 3500 Australians to volunteer for EDGI.

“We are looking for any Australians, aged 13 and over, with first-hand experience of an eating disorder, to volunteer for this important genetics study,” Professor Martin said.

“Decades of family and twin studies have confirmed that eating disorders run in families due to genetic factors.⁷

“Breakthroughs made possible with genome-wide association studies (GWAS), such as EDGI, use postage-stamp-sized ‘genetic chips’ to allow analysis of up to one million genetic markers.⁸ These markers investigate single letter variations in the DNA (A,C,G,T — the building blocks of DNA) across all 23 chromosomes.⁹

“Each of these variants can then be tested statistically for association with eating disorders, by comparing the genomes of large numbers of individuals with eating disorders to large numbers of individuals without the diseases,” Professor Martin explained.

“Analysing the DNA from study saliva samples will allow us to pinpoint specific genes associated with eating disorders, which will help us to determine why some people experience eating disorders, and why some people living with eating disorders respond to certain treatments, while others do not.

“Comparing the saliva samples of EDGI participants to samples collected for other disorders will also help us to understand the common conditions co-occurring with eating disorders, including obsessive-compulsive disorder, depression, anxiety, substance abuse disorders and personality disorders,” Professor Martin said.

According to Sydney-based Clinical Psychologist and Director of the InsideOut Institute for Eating Disorders Dr Sarah Maguire, eating disorders are not a choice, but rather, serious illnesses that can cause significant distress and affect the lives of individuals, their partners, families, carers and friends.

“For far too long, eating disorders have been perceived as illnesses that pivot around the external; a physical ideal and pursuit of beauty or body image. In reality, however, eating disorders are mental illnesses driven by what is going on in the mind, and involve a complex interplay of environmental and genetic factors,” Dr Maguire explained.

Volunteers must be aged 13 years or over* and have currently, or at any point in their lives, experienced, anorexia nervosa, bulimia nervosa or binge eating disorder.

*Children aged 13 to 17 years wishing to volunteer for the study must be supervised by a guardian.

To learn more or to register for the study, visit www.edgi.org.au.

References

1. Bulik, C., Martin, N. Finding pieces of the puzzle: Australia and New Zealand anchoring the Eating Disorders Genetics Initiative (EDGI) 2020.
2. Watson, H.J., et al., Genome-wide association study identifies eight risk loci and implicates metabo-psychiatric origins for anorexia nervosa. Nature Genetics, 2019. 51(8): p. 1207-1214.
3. National Eating Disorders Collaboration. What is an eating disorder? [cited October 2019]; Available from: https://www.nedc.com.au/eating-disorders/eating-disorders-explained/something/whats-an-eating-disorder/.
4. Ministry of Health. Future Directions for Eating Disorders Services in New Zealand. 2008. [cited Dec, 2019]; Available from: https://www.health.govt.nz/system/files/documents/publications/future-directions-eating-disorders-services-nz-v2.pdf.
5. Smink, F.R.E., D. van Hoeken, and H.W. Hoek, Epidemiology of eating disorders: incidence, prevalence and mortality rates. Current psychiatry reports, 2012. 14(4): p. 406-414.
6. Fichter, M. and N. Quadflieg, Mortality in eating disorders - Results of a large prospective clinical longitudinal study. The International journal of eating disorders, 2016. 49.
7. Wade, T.D., et al., Prevalence and long-term course of lifetime eating disorders in an adult Australian twin cohort. Aust N Z J Psychiatry, 2006. 40(2): p. 121-8.
8. Gene chips, in Rheumatology and Immunology Therapy, J.D. Abbott, et al., Editors. 2004, Springer Berlin Heidelberg: Berlin, Heidelberg. p. 347-347.
9. National Institutes of Health (US); Biological Sciences Curriculum Study. NIH Curriculum Supplement Series [Internet]. Bethesda (MD): National Institutes of Health (US); 2007. Understanding Human Genetic Variation. 2007 [July 2020]; Available from: https://www.ncbi.nlm.nih.gov/books/NBK20363/.

Image courtesy of EDGI.