Two Genes Found To Influence Anorexia
PITTSBURGH, May 19, 2003 An international team of researchers has identified two genes associated with anorexia in families and patients with the eating disorder. The study, in today's Molecular Psychiatry, provides a direct genetic connection between anorexia and the brain mechanisms controlling appetite and anxiety, two hallmarks of eating disorders.
Anorexia nervosa is a serious and potentially lethal illness. It is characterized by the relentless pursuit of thinness and emaciation, and the obsessive fear of gaining weight. It commonly begins during adolescence in girls and it runs in families. A number of traits, such as perfectionism, anxiety and obsessionality contribute to the risk of developing anorexia.
We used a process called candidate gene association analysis to identify two genes from a region on the short arm chromosome 1, previously identified as likely to contain genes contributing to anorexia nervosa, that may contribute to the risk of developing anorexia nervosa, said author Andrew W. Bergen, Ph.D., currently staff scientist at the National Cancer Institutes Core Genotyping Facility in Gaithersburg, Md. When we compared anorexia patients to control individuals, we found statistically significant association of sequence polymorphisms at these two genes to anorexia nervosa, with increasing risk to individuals carrying specific alleles for developing anorexia nervosa.
To perform the gene association analysis, the researchers focused on a region of the short arm of chromosome 1 that earlier studies by the same researchers found was likely to contain genes contributing to anorexia nervosa in families. The researchers used a process known as candidate gene analysis to investigate several genes in the chromosome 1 region, using both positional information and biological information about genes in this region to nominate three genes for detailed analysis. In the candidate gene association analysis, the researchers analyzed sequence polymorphisms in DNA samples from families with anorexia and other eating disorders and from individuals not affected with anorexia nervosa. Two genes in the chromosome 1 region, HTR1D, the gene that codes for the serotonin 1D receptor, and OPRD1, the gene that codes for the delta opioid receptor, demonstrated statistically significant association to anorexia nervosa.
This study is evidence that were on the right track in our search for genes that contribute to eating disorders, said Walter H. Kaye, M.D., professor of psychiatry at the University of Pittsburgh and principal investigator for the study. And, while we still have much work to do, these efforts could eventually lead to more effective treatments or preventive measures.
Funding for the study was provided by the Price Foundation, which has provided financial support for the research team for more than a decade, described at http://www.anbn.org.
For more information on how to participate in genetic studies for eating disorders, please call 1-888-895-3886 or visit the Web site at www.angenetics.org.