Anorexia genes uncovered
Australian researchers have helped identify genes associated with anorexia.
It is the first evidence to suggest anorexia comes from both the body and the mind.
QIMR Berghofer researchers played a vital role in outlining first eight genes associated with the eating disorder.
Anorexia nervosa is a life-impairing illness characterised by dangerously low body weight, an intense aversion to gaining weight, and an inability or unwillingness to recognise the seriousness of the low body weight.
It is seen primarily in women, with as many as one in 200 expected to be affected in their lifetimes.
Researchers recruited nearly 3,000 Australians and New Zealanders who had lived with the chronic eating disorder to contribute DNA for the study of 16,992 anorexia cases from around the world.
The genetic information of people with lived experiences of the disorder was compared to DNA from 55,525 controls of European ancestry from 17 countries across North America, Europe, and Australasia.
Researcher Professor Nicholas Martin says it is a huge step forward in understanding the disorder.
“We’ve got the first eight genes, but we know there are hundreds more genes to find, and we can only do that by broadening the study and recruiting more participants. I am hoping that this success will encourage other Australians living with eating disorders to volunteer to help us find the responsible genes,” Professor Martin said.
“By showing the role genetics plays in anorexia nervosa we should be able to remove any remaining stigma associated with the condition for patients and their families – especially parents.
“Australians and New Zealanders provided a fifth of the information needed to confirm the genetic basis of this potentially life-threatening condition and I want us to continue to play a big role in expanding our knowledge of eating disorders.
“Our goal is to recruit 100,000 anorexia nervosa cases internationally with appropriate controls, and to also broaden our search beyond anorexia nervosa to include other eating disorders such as bulimia and binge eating disorder.”
Principal investigator Professor Cynthia Bulik says it will influence treatment.
“Until now, our focus has been on the psychological aspects of anorexia nervosa such as the patients’ drive for thinness. Our findings strongly encourage us to also shine the torch on the role of metabolism to help understand why individuals with anorexia frequently drop back to dangerously low weights, even after therapeutic renourishment,” Professor Bulik said.
“A failure to consider the role of metabolism may have contributed to the poor track record among health professionals in treating this illness.”
QIMR Berghofer’s Professor Sarah Medland said the wide-ranging research also uncovered other important information on the illness.
“The study found the genetic basis of anorexia nervosa overlapped with other psychiatric disorders such as obsessive-compulsive disorder, depression, anxiety, and schizophrenia, and this underscores the importance of taking a broad clinical focus in working with individuals who experience an eating disorder,” she said.
The study also found the genetic basis of anorexia nervosa overlapped with metabolic (including glycemic), lipid (fats), and anthropometric (body measurement) traits, and that was not due to genetic effects that influence BMI.
Professor Martin is encouraging anyone who has lived with anorexia nervosa, bulimia or other eating disorders to sign up to the next stage of the study and provide a saliva sample from which DNA can be extracted.