“So that’s pretty exciting, it’s the first clue we’ve got as to what the genetic processes are behind anorexia,” Professor Martin said.
“The results were interesting – we thought the genes would be mostly linked to behavioural genes and that’s true for some of them, there’s a strong [genetic] connection between anorexia and obsessive compulsive disorder, for example.
“But the other part we hadn’t expected to see is strong links to metabolism, both in terms of body build, body weight and genes involved in diabetes.”
Importantly, the genes linking anorexia with metabolism were not the common variants associated with body-mass index, meaning something more complex was going on at a genetic level.
‘It’s not all in my head’
Sarah Lady just started talking to her mother again earlier this year, after they had a falling-out over Ms Lady’s anorexia diagnosis.
“My mother was so angry at me, for the first five years she thought I was attention seeking, in her own words, she literally asked me why couldn’t I just eat a sandwich,” she said.
“If she could have known that there was a genetic predisposition there, her attitude would have been so different, I’m sure.”
She said following her diagnosis, her doctors worked backwards based on her own evidence and concluded she had had an eating disorder since she was a teenager, but the condition became full-blown anorexia following a relationship break-up when she was 31.
“Being diagnosed later in life means you’re really up against incredible habitual patterns both mentally and physically – skipping meals, judging yourself, paranoia,” she said.
This is a monster in society that has so many things feeding it.
Now 37 with three children, Ms Lady still struggles with anorexia and feels she’s “too fat” but is getting treatment for her condition and says she decided not to keep sacrificing parts of her life to it.
“I’m a singer in a punk band, and women would come up to me in the ladies’ toilets after the show and say, ‘You’re so lucky you’re so skinny’,” she said.
“I cut them off now, after years of therapy, and say, ‘No, this has robbed me of dinner with my children, of birthday cakes, of intimacy with my partner, I’m not lucky’.”
Potentially hundreds more genes
Professor Martin said the eight genes identified so far were the tip of the iceberg when it came to understanding the underlying physical causes of anorexia.
“I think there’ll be hundreds [more genes linked to anorexia], because for example with schizophrenia, we’re already up to almost 200, while depression it’s around 100 and bipolar it’s around 30.
“So we’re absolutely sure there’s a lot more to find, and it’s just a question of getting a large-enough sample size.”
He called on anyone who had had anorexia and wanted to participate in the follow-up study to come forward, with a goal of getting 100,000 participants worldwide.
It was hoped the more people to sample, the more genes could be identified, which could lead to possible drugs that could target the condition specifically, instead of doctors treating surrounding conditions such as depression.
Ms Lady, one of the original participants in the QIMR study, encouraged people with the condition to take part in future trials.
“This is a monster in society that has so many things feeding it,” she said.
Anyone wanting to take part in the future study can visit edgi.qimr.edu.au or phone 1800 257 179.
The research has been published this week in the journal Nature Genetics.
Stuart Layt covers health, science and technology for the Brisbane Times. He was formerly the Queensland political reporter for AAP.