Anorexia nervosa (AN) seems to affect women 10 times more frequently than men and has the highest mortality rate of all psychiatric disorders. Patients suffering from this condition may have food refusal, weight loss, an irrational fear of weight gain even when emaciated, as well as distorted self-image of body weight and shape. Investigators from The Children’s Hospital of Philadelphia have supposedly found common and rare gene variants related to AN.
Scientists triggered a genome-wide association study on a large anorexia cohort in which a parallel search for copy number variations (CNVs) was performed. CNVs are known as rarer variants usually having a stronger impact on disease risk. During the investigation DNA sample of 1,003 AN patients was scrutinized by the experts. The average age of all the participants except for 24 women was 27 years. The results were then compared to a control group of 3,733 pediatric subjects with an average age of 13 years. It was observed that SNPs in the gene OPRD1 and near the gene HTR1D probably heighten risk for the disease.
Hakon Hakonarson, MD, PhD, director of the Center for Applied Genomics at The Children’s Hospital of Philadelphia and lead researcher, commented, “Our study suggests that both common SNPs and rare CNVs contribute to the pathogenesis of anorexia nervosa. The gene variants we discovered are worthy of further analysis in independent cohorts. However, the relatively modest number of anorexia cases explained by these results we found suggests that many other candidate genes remain unknown. Future studies will require much larger sample sizes to detect additional gene variants involved in this complex disorder.”
Also CNVs—deletions or duplications of DNA sequences was thoroughly examined in the investigation. Apparently CNVs have a major role in various other neuropsychiatric disorders like schizophrenia, bipolar disorder and autism. However, CNVs supposedly play a less important role during anorexia than that in schizophrenia and autism. Innumerable rare CNVs occurring only in AN cases namely deletion of DNA on a region of chromosome 13 were registered.
The research was published online in Molecular Psychiatry on November 16.