Finding better genes- the Anorexia Nervosa Genetics Initiative

Recently, the University of North Carolina Eating Disorders Center announced the beginning of ANGI: the Anorexia Nervosa Genetics Initiative. The goal is to gain a better understanding of the genes involved in AN.

When I heard this announcement, I immediately wanted to know more. So I got in touch with lead investigator Cynthia Bulik and project coordinator Laura Thornton, who told me more about ANGI and what it means to the research community and those of us with EDs.

ANGI_Logo_Deliver

1) So what is ANGI? Why do we need it?

ANGI stands for the Anorexia Nervosa Genetics Initiative. It’s an international collaborative effort aimed at identifying genes that increase risk for anorexia nervosa and includes researchers from the US, Australia, Sweden, and Denmark.

We know anorexia is characterized by dangerously low body weight and can be deadly. It affects about one out of every 100 people, particularly girls and women, but we don’t know why. Because we do not have a full understanding of anorexia’s etiology, it is difficult to develop novel treatments. We think that by discovering which genes increase risk for anorexia we’ll be better able to understand why it develops, target prevention efforts, and develop new treatments. But we need help! To unlock the genetics of anorexia we need

16,000 people to participate, both people with and without a history of anorexia.

2) What types of questions do you hope ANGI answers?

The first goal of ANGI is to identify areas in the genome that contribute to the risk for anorexia nervosa.  This is a huge undertaking in and of itself!  Once we discover those genes, we can begin to figure out a lot about the biology of anorexia by examining the ways these genes interact with each other and with the environment.  We can also focus on the complicated ways these genes get expressed across the lifespan and evaluate if there are critical periods of time that we need to focus our intervention.

3) Why do you need so many participants?

It boils down to statistics.  When you’re looking at so many genes all at the same time, there’s a likelihood that you might find one that appears to be statistically related but really it’s just due to chance.  So, large numbers of people are needed in this study to ensure that the associations discovered between genes and the disease are, in fact, true associations. The more participants we can get around the world, the more likely we will yield results. Schizophrenia was in a similar state as anorexia about 6 years ago and, as they increased their sample size, they have been identifying more and more gene variants that contribute to that disorder. It is an exciting if not transformational time for the field and it is time for anorexia nervosa to join this exciting tide.

4) One of the many comments I get from people is that they have a hard time believing that AN (or EDs in general) have genetic influences because there’s no “anorexia gene.” Can you explain a bit more about what we know about AN genetics and why we don’t need an “anorexia gene”?

Over the last 30 years, a number of studies have demonstrated over and over again that anorexia is heritable.  For example, family studies show that risk to first-degree relatives of those with anorexia is dramatically elevated compared with the risk to the general population. That means that if you have an immediate family member with anorexia, like your mother, your brother, or your sister, that your risk of also having anorexia is higher.  Twin studies are another way to estimate the genetic risk for eating disorders.  In a twin, study identical twins (who share 100% of their genes) are compared with fraternal twins (who share 50% of their genes).  If both members of an identical twin pair are more likely to have anorexia (be concordant) than both members of a fraternal twin pair, we can assume that genetic factors are influencing that outcome.  Using these data, we estimate that the heritability of anorexia is over 60%. Lastly, studies exploring sociocultural theories have not been able to explain the fact that anorexia remains rare in cultures with a thin ideal.

So, why don’t we need an “anorexia gene?” Psychiatric illnesses are complex and are influenced by many genes, maybe even hundreds, each working together and each with a small effect.  However, if you put them together, along with environmental factors, they can increase your risk for the disease significantly. The Human Genome Project and advances in computer processing speed have moved the field of genetics forward and we can now look at the whole genome, which is amazing!

5) Can better genetic information lead to better treatments? If so, how? 

It’s not going to happen overnight, but certainly better genetic information can eventually lead to better treatments. Genetic information will help us know who is at risk for developing anorexia nervosa and help us with prevention and early identification.  This is a critical first step in understanding the biology of anorexia nervosa. It will inform future neuroscience research, the development of medications for anorexia and even help us personalize therapy.  Getting to that place is a very long road but everyone who participates in ANGI is a citizen scientist who will contribute immeasurably to helping children and adults avoid the heartache that anorexia wreaks on families and lives. We can’t do it without you.

6) What could these results tell us about preventing AN?

The results of the study will inform the next research steps. Prevention information is much further down the line, but each step we take is progress. Once we have identified variants, it may be possible to create a genetic risk profile that may help us understand who (genetically) is at greater risk for developing anorexia.

7) If people want to participate, what do they need to know? What about people (like me!) who want to participate but don’t live near a clinical center?

In the US, you have to be a girl or woman who at least 12 years of age to participate.  The first step is to speak with one of the researchers about ANGI (send an email to angi@unc.edu). We will give you a brief overview of ANGI and review the consent required to participate. The consent form is a document that explains everything about ANGI and covers the benefits and risks of participating.  After that, we’ll invite you to fill out an online survey (15-30 minutes) and submit a blood sample. If you do not live near North Carolina and can’t come to UNC, we’ll send you a package with detailed directions on how to send your blood sample. You can get your blood drawn at your local doctor’s office or lab, wherever you feel most comfortable. The box with your blood is then shipped back via FedEx with prepaid shipping. If your doctor’s office charges you to take your blood, just keep the receipt and we’ll send you a check to reimburse you for the cost of the blood draw. Once we get the blood sample, we’ll also send you a $25 Amazon.com gift card to say thank you!

If you live in Australia, the Queensland Institute for Medical Research and Flinders University are taking the lead.

If you live in Sweden, you can contact one of the quality registers, RIKSÄT or STEPWISE, to get more information.

We have already had a number of people contact us who want to participate but they live in Canada or the UK, or in another country.  One of the reasons we can’t just send them a package with instructions is that it is extremely hard to ship blood internationally.  If you’ve ever tried to bring an apple through customs, you can imagine what a headache it might be to send blood into a different country.  We’re working on ways for everyone to participate in the future though, so stay tuned for updates.  We’ll find a way to make it happen.


If you want to know more, please email angi@unc.edu!

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6 Responses to “Finding better genes- the Anorexia Nervosa Genetics Initiative”

  1. Sarah Stephenson May 24, 2013 at 5:05 pm

    Brilliant news – I think the more research, the better! Its just a shame that we Brits can’t offer our help with this one!

  2. Jacques Neher May 25, 2013 at 11:27 am

    This is huge. But we need some clarification:

    1. Why the 4-year timeline? Given the number of sufferers and the huge existing professional infrastructure — hospitals, treatment centers, local and national ED organizations — One would think that the necessary pool of participants could be gathered in 4 months rather than 4 years. I can’t imagine any parent of an AN sufferer not wanting their child to participate in such a research project.

    2. Why exclude males from the study? If the research succeeds in identifying genes at play in AN, wouldn’t it be logical to see those same genes in male sufferers?

    3. AN rarely manifests by itself. Are the researchers going to take note of the host of comorbid or associated disorders in their samples? What about other eating disorders that may come and go in the life of an AN sufferer? Might it be possible to make genetic sense of those disorders as well?

    4. Are parents and siblings of an AN sufferer invited to participate as part of the “normal” control group?

  3. Carli Whitchurch May 26, 2013 at 3:32 pm

    I’m participating in this study– I spoke with the researcher at length on the phone, getting the low-down and going through the consent process. Completed the survey and am expecting my package for the blood sample to arrive in the mail next week. Jacques, I can’t answer all of your questions but I can clarify a couple: The survey does not simply ask whether or not the individual has/has had anorexia nervosa– it asks many specific questions about eating disordered behaviors. I believe this current study is only looking at the genetic component in AN. It makes sense to me that this should be the first step– and yes, it would hopefully pave the way to future studies that would look at comorbidity and crossover! Parents and siblings ARE invited to participate as part of the “normal” control group and the researchers will be including that in their data, asking that they be informed about any relatives who are participating.

    • Jacques Neher May 27, 2013 at 7:52 pm

      “Parents and siblings ARE invited to participate as part of the “normal” control group and the researchers will be including that in their data, asking that they be informed about any relatives who are participating.”
      Thanks for this info.

  4. awesome, but why can’t the study focus on ALL eating disorders? anorexia is not the only one, and MOST eating disordered people are diagnosed with EDNOS.

    • Carrie Arnold May 31, 2013 at 6:52 pm

      EDNOS is too heterogeneous to do a good genetic analysis on. You need pretty strict criteria to do a gene search so any signals don’t get drowned out by white noise.