Genetics and Anorexia Nervosa – Anomalies on Chromosome 12

Eating disorders are biopsychosocial disorders, meaning, the behaviors are impacted by biology, psychology, and sociology.

Social aspects of eating disorders are often discussed. However, the biological aspect is one with which people are less familiar. Even so, the genetic aspects of anorexia nervosa (AN) are essential to better understanding the disease.

The Numbers
The genetics of Anorexia have been studied from many angles such as family and twin studies, linkage studies, and candidate gene studies. Many of these findings support the fundamental concept that there is a significant genetic contribution to the existence of AN.

One study found that “replicated heritability for AN have ranged between 48 and 64% [1].”

Not only that, studies have determined that, despite not being discussed as much as social and psychological aspects, “genes are approximately 60% responsible for the development of anorexia nervosa [2].”

Those statistics are incredible to consider, that over half of the responsibility for the existence of AN is the result of something one has no control over – their own DNA. This further solidifies the belief that many researchers and clinicians have that struggling with an eating disorder is not the result of individual choice.

New Horizons
Beyond this, for some time technology limited researcher’s ability to learn more or pinpoint precisely how/where this genetic predisposition or alteration occurs. However, technological and research advancements have allowed researchers to look further, with incredible results.

A study done by the University of North Carolina and published in the American Journal of Psychiatry has pinpointed that “anorexia nervosa is associated with genetic anomalies on chromosome 12.” [2]

This groundbreaking information has also led to other realizations about AN. Research has found that Chromosome 12 also played a significant role in other disorders such as Type 1 diabetes, autoimmune diseases, and insulin metabolism [2].

Black woman in Eating Disorder Treatment Specifically for WomenNot only that, it found genetic correlations between AN, neuroticism, and schizophrenia, “supporting the idea that anorexia is a psychiatric illness [2].”

Now What
These results have opened doors for future research as well as treatment.

This information shows a positive genetic correlation between schizophrenia and AN indicates “substantial evidence for partially shared genetic risk [3],” something to be considered when working with individuals showing symptoms or diagnoses of either.

This study provided further evidence that AN is “a complex, heritable phenotype with intriguingly large and significant genetic correlations not only with psychiatric disorders but multiple metabolic traits. [3].”

This changes treatment, as AN was previously considered predominantly to be a psychiatric disorder. Looking at AN from both a psychiatric and metabolic perspective may result in improved treatment methods and outcomes.