Could genetics be the key to treating anorexia?

Eating disorders are thought to affect nearly 1m Australians1, with anorexia nervosa, bulimia and binge eating disorders the most common.

All eating disorders can have serious consequences, and because of the typical symptoms of fear of weight gain and severely restricted eating, untreated anorexia is associated with devastating physical consequences and has a high mortality rate. The condition can affect people of any age but the most severe illness commonly occurs in the 20-45 year age group, and the disease is more common in women.2

Anorexia is often viewed as a condition based largely on external factors such as media and advertising featuring unrealistic images of the body. However in many cases the role of these external factors including trauma, abuse or societal pressure is to trigger the disease in a person who may be predisposed to anorexia because of their genetics.

It has long been known that family history is a risk factor for anorexia but a large global study has now been able to better pinpoint contributing factors.

Researchers at the University of North Carolina (pictured above) collaborated with institutions across the US and Europe bringing together 220 scientists to analyse genomic data from 3,495 people with anorexia nervosa and 10,982 unaffected people.

The researchers found genetic variations on chromosome 12 that were common to the participants with anorexia – this region of chromosome 12 is also associated with Type 1 diabetes and autoimmune disorders.2

Investigators also found genetic correlations with certain metabolic factors including a person’s Body Mass Index (BMI) and their insulin-glucose metabolism.

There are currently no drug treatments specifically for anorexia. Greater understanding of factors that contribute to a person’s risk of developing anorexia is important in developing effective treatments; either new therapies or existing drugs used for other conditions.

Lead Investigator Professor Cynthia Bulik from University of North Carolina said:

“Anorexia is a devastating illness and is not well understood in the community. This research is a big step in pinpointing where predisposition to the disease begins and encourages us to look more deeply at how metabolic factors increase the risk for anorexia. We want to find ways to target treatment and data like this is a key part of that process.”

Prof Bulik leads the Anorexia Nervosa Genetics Initiative (ANGI) which has joined with a project called AN25K, collecting 25,000 blood samples from people across the globe who have been diagnosed with anorexia nervosa.

Large sample sizes are critical when looking at the genetics of psychiatric illnesses as many genes may be involved in disease risk.

More research is needed but these latest findings mean that genetic testing could one day be part of guiding effective treatment for people with anorexia.

1 https://www.eatingdisorders.org.au/key-research-a-statistics

2 http://ajp.psychiatryonline.org/doi/abs/10.1176/appi.ajp.2017.16121402?journalCode=ajp